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Background: This study aimed to evaluate loss of protective anti-hepatitis B (HBs) titers and seroconversion to hepatitis B vaccine (HBV) during chemotherapy in children with acute lymphoblastic leukemia (ALL)., Methods: Anti-HBs titers were done at diagnosis. Patients were divided into two groups. Group I (protective titers >10 mIU/ml) received single double dose of HBV as booster. Titers were repeated at three time points: end of phase 1b, beginning of re-induction, and start of maintenance chemotherapy. Group II (nonprotective titers <10 mIU/L) received hepatitis B immunoglobulin (HBIG), prior to start of chemotherapy, followed by three double doses of HBV as booster. Titers were repeated at two time points: prior to first dose, and 4 weeks after third dose of vaccine., Results: Total 125 patients were included: 88 in group I; 37 in group II. Among group I patients, 98.7%, 90%, and 84% retained protective titers at the three points, respectively. Subgroup analysis showed that those with initial titers greater than 100 mIU/L retained protective titers better than those with titers between 11 and 100 mIU/L (p = .0001). Among group II patients, 62% and 64% attained protective titers at the two points, respectively., Conclusions: HBV boosters helped maintain protective titers during intensive ALL chemotherapy in immunized children having titers more than 10 mIU/L, and more so if titer was more than 100 mIU/L. Therefore, we propose that cut off for protective anti-HBs titers be changed to greater than or equal to 100 mIU/L. Titers between 11 and 100 mIU/L may require combined active and passive immunization. Around one-third of group II patients who fail to attain protective titers may need frequent doses of HBIG., (© 2022 Wiley Periodicals LLC.)

Marek's disease (MD) vaccines are cell-associated and require special handling and care during administration. Vaccine dose is evaluated by plaque assay and is indicated as the number of plaque-forming units (PFUs) per dose. The objectives of this study were to evaluate the dose variability within each vial of MD vaccines and to assess those factors (from both manufacturing and handling and administration of the vaccine) that could affect vaccine dose variability. Three experiments were conducted. Experiment 1 was to evaluate dose variability in 36 MD vaccine vials and the effect of manufacturing factors on dose variability. Vaccines were titrated 10 times. Dose variability was measured as the coefficient of variability (CV) calculated as standard deviation divided by average PFU and multiplied by 100. Our results showed that all evaluated vaccines had levels of CV ranging from 10% to 34%. Variability existed regardless of manufacturer, vaccine serotype, and batch. Experiment 2 was conducted to evaluate the effect of infectivity rate (IR) on CV. IR was artificially reduced by adding noninfected chicken embryo fibroblast to the reconstituted vaccine before titration. Our results showed that decreased IR results in higher CV. Experiment 3 was to evaluate the handling and administration factors (time and mixing during administration) on CV. Our results showed that CV tends to increase with time and that this effect is more remarkable if vaccines were not mixed. Our study emphasizes the relevance of proper handling of MD vaccines and shows that dose variability can jeopardize the uniformity of vaccination in a flock and therefore the success of vaccination.

COVID‐19 vaccine became available in Tanzania during the first wave of the Omicron variant. During that time community seroprevalence of SARS‐CoV‐2 was already at 50%–80%. To date, it remains largely unknown whether ongoing vaccination with the primary series vaccines has any meaningful immune‐boosting effects against newer Omicron subvariants. Therefore, we tested cross‐neutralizing capacity of antibodies elicited by infection, vaccination, or both against SARS‐CoV‐2 Omicron subvariants BA.1, and the newer subvariants BQ.1.1 and XBB.1.5. that were unexperienced by this population. Participants who were either SARS‐CoV‐2 infected‐only (n = 28), infected vaccinated (n = 22), or vaccinated‐only (n = 73) were recruited from Dar‐es‐Salaam, Tanzania, between April and December 2022. Plasma 50% neutralization titers (NT50) against SARS‐CoV‐2 wild‐type strain and Omicron subvariants were quantified by a lentiviral‐based pseudo‐virus assay. Percentage of participants with neutralizing activity against WT and BA.1 was high (>85%) but was reduced against BQ.1.1 (64%–77%) and XBB.1.5 (35%–68%) subvariants. The low median cross‐neutralization titer was slightly higher in the infected vaccinated group compared to vaccine‐only group against BQ.1.1 (NT50 148 vs. 85, p = 0.032) and XBB.1.5 (NT50 85 vs. 37 p = 0.022) subvariants. In contrast, vaccine‐boost among the infected vaccinated did not result to increased cross‐neutralization compared to infected‐only participants (BQ.1.1 [NT50 of 148 vs. 100, p = 0.501] and XBB.1.5 [NT50 86 vs. 45, p = 0.474]). We report severely attenuated neutralization titers against BQ.1.1 and XBB.1.5 subvariants among vaccinated participants, which marginally improved in the infected vaccinated participants. Our findings call for further studies to evaluate effectiveness of the primary series vaccines in preventing severe infection and mortality against the newer variants. [ABSTRACT FROM AUTHOR]

While gilts and sows are regularly vaccinated against the porcine parvovirus (PPV), little is known on the presence of antibodies in vaccinated sows nor the decline of maternally derived antibodies (MDA) in their offspring. On twelve farms serum samples were taken from 180 gilts and sows vaccinated at least twice with one of three different commercial PPV vaccines. On nine farms, additional 270 serum samples were collected from growing pigs of three different age categories. All 450 samples were examined for PPV antibodies (Abs) by ELISA and haemagglutination inhibition (HI) assay. In total, 65% of all gilts vaccinated twice with either vaccine 1 or vaccine 3 were seronegative by HI assay. In each farm, there were at least three animals with high Ab titres (≥ 1:1280) indicating the presence of PPV in all twelve study farms. However, PPV DNA could not be detected in collected faecal samples. While low to moderately high Ab titres (1:10–1:640) were measured in 98% of twelve-weeks-old pigs, ELISA was only positive in 30% of the same pigs. Though, the statement on the duration of MDA may depend on the applied test, we could confirm an exponential decay of MDA. In addition, we could demonstrate that applied serological tools are insufficient for the confirmation of successful vaccination. [ABSTRACT FROM AUTHOR]

The emergence of new SARS-CoV-2 variants continues to cause challenging problems for the effective control of COVID-19. In this study, we tested the hypothesis of whether a strategy of multivalent and sequential heterologous spike protein vaccinations would induce a broader range and higher levels of neutralizing antibodies against SARS-CoV-2 variants and more effective protection than homologous spike protein vaccination in a mouse model. We determined spike-specific IgG, receptor-binding inhibition titers, and protective efficacy in the groups of mice that were vaccinated with multivalent recombinant spike proteins (Wuhan, Delta, Omicron), sequentially with heterologous spike protein variants, or with homologous spike proteins. Trivalent (Wuhan + Delta + Omicron) and sequential heterologous spike protein vaccinations were more effective in inducing serum inhibition activities of receptor binding to spike variants and virus neutralizing antibody titers than homologous spike protein vaccination. The higher efficacy of protection was observed in mice with trivalent and sequential heterologous spike protein vaccination after a challenge with a mouse-adapted SARS-CoV-2 MA10 strain compared to homologous spike protein vaccination. This study provides evidence that a strategy of multivalent and sequential heterologous variant spike vaccination might provide more effective protection against emerging SARS-CoV-2 variants than homologous spike vaccination and significantly alleviate severe inflammation due to COVID-19. [ABSTRACT FROM AUTHOR]

An important consideration for biopharmaceutical processes is the cost of goods (CoGs) of biotherapeutics manufacturing. CoGs can be reduced by dramatically increasing the productivity of the bioreactor process. In this study, we demonstrate that an intensified process which couples a perfused N‐1 seed reactor and a fully automated high inoculation density (HID) N stage reactor substantially increases the bioreactor productivity as compared to a low inoculation density (LID) control fed‐batch process. A panel of six CHOK1SV GS‐KO® CHO cell lines expressing three different monoclonal antibodies was evaluated in this intensified process, achieving an average 85% titer increase and 132% space–time yield (STY) increase was demonstrated when comparing the 12‐day HID process to a 15‐day LID control process. These productivity increases were enabled by automated nutrient feeding in both the N‐1 and N stage bioreactors using in‐line process analytical technologies (PAT) and feedback control. The N‐1 bioreactor utilized in‐line capacitance to automatically feed the bioreactor based on a capacitance‐specific perfusion rate (CapSPR). The N‐stage bioreactor utilized in‐line Raman spectroscopy to estimate real‐time concentrations of glucose, phenylalanine, and methionine, which are held to target set points using automatic feed additions. These automated feeding methodologies were shown to be generalizable across six cell lines with diverse feed requirements. We show this new process can accommodate clonal diversity and reproducibly achieve substantial titer uplifts compared to traditional cell culture processes, thereby establishing a baseline technology platform upon which further increases bioreactor productivity and CoGs reduction can be achieved. [ABSTRACT FROM AUTHOR]

As use of the ferret model to study influenza A virus (IAV) pathogenicity increases, periodic assessment of data generated in this model is warranted, to identify features associated with virus replication throughout the respiratory tract and to refine future analyses. However, protocol-specific differences present between independent laboratories limit easy aggregation of virological data. We compiled viral titer and clinical data from >1,000 ferrets inoculated with 125 contemporary IAV under a consistent experimental protocol (including high- and low-pathogenicity avian, swine-origin, and human viruses, spanning H1, H2, H3, H5, H7, and H9 subtypes) and examined which meaningful and statistically supported associations were present among numerous quantitative measurements. Viral titers correlated positively between ferret nasal turbinate tissue, lung tissue, and nasal wash specimens, though the strength of the associations varied, notably regarding the particular nasal wash summary measure employed and properties of the virus itself. Use of correlation coefficients and mediation analyses further supported the interconnectedness of viral titer measurements taken at different sites throughout the respiratory tract. IAV possessing mammalian host adaptation markers in the HA and PB2 exhibited more rapid growth in the ferret upper respiratory tract early after infection, supported by quantities derived from infectious titer data to capture infection progression, compared with viruses bearing hallmarks of avian IAV. Collectively, this work identifies summary metrics most closely linked with virological and phenotypic outcomes in ferrets, supporting continued refinement of data analyzed from in vivo experimentation, notably from studies conducted to evaluate the public health risk posed by novel and emerging IAV. IMPORTANCE Ferrets are frequently employed to study the pandemic potential of novel and emerging influenza A viruses. However, systematic retrospective analyses of data generated from these experiments are rarely performed, limiting our ability to identify trends in this data and explore how analyses can be refined. Using logarithmic viral titer and clinical data aggregated from one research group over 20 years, we assessed which meaningful and statistically supported associations were present among numerous quantitative measurements obtained from influenza A virus (IAV)- infected ferrets, including those capturing viral titers, infection progression, and disease severity. We identified numerous linear correlations between parameters assessing virus replication at discrete sites in vivo, including parameters capturing infection progression not frequently employed in the field, and sought to investigate the interconnected nature of these associations. This work supports continued refinement of data analyzed from in vivo experimentation, notably from studies which evaluate the public health risk posed by IAV. [ABSTRACT FROM AUTHOR]

To analyze the relationship between homologous and heterologous serological titers of immunized pigs and their protection statuses against FMD virus challenges, in the present study, the correlation between the virus neutralization titers at 21 and 28 dpv and the protection statuses at 28 dpv against challenge with FMD virus was analyzed using data sets comprising five different combinations of homologous or heterologous challenge experiments in pigs vaccinated with type O (n = 96), A (n = 69), and Asia 1 (n = 74). As a result, the experiments were divided into three groups (21D-1, 21D-2, and 21D-3) in the 21-dpv model and two groups (28D-1 and 28D-2) in the 28-dpv model. Each response curve of groups 21D-1 and 21D-2 in the 21-dpv model was very similar to each curve of groups 28D-1 and 28D-2 in the 28-dpv model, respectively, even though there was an exceptional extra group (21D-3) in the 21-dpv model. The average titers estimating 0.75 probability of protection ranged from 1.06 to 1.62 log10 in the 21-dpv model and from 1.26 to 1.64 log10 in the 28-dpv model. In summary, we demonstrated that the serological method is useful for predicting the homologous and heterologous protection statuses of vaccinated pigs. [ABSTRACT FROM AUTHOR]

Although the anti-COVID-19 vaccination has proved to be an effective preventive tool, "breakthrough infections" have been documented in patients with complete primary vaccination courses. Most of the SARS-CoV-2 neutralizing antibodies produced after SARS-CoV-2 infection target the spike protein receptor-binding domain which has an important role in facilitating viral entry and the infection of the host cells. SARS-CoV-2 has demonstrated the ability to evolve by accumulating mutations in the spike protein to escape the humoral response of a host. The aim of this study was to compare the titers of neutralizing antibodies (NtAbs) against the variants of SARS-CoV-2 by analyzing the sera of recovered and vaccinated healthcare workers (HCWs). A total of 293 HCWs were enrolled and divided into three cohorts as follows: 91 who had recovered from SARS-CoV-2 infection (nVP); 102 that were vaccinated and became positive after the primary cycle (VP); and 100 that were vaccinated with complete primary cycles and concluded the follow-up period without becoming positive (VN). Higher neutralization titers were observed in the vaccinated subjects' arms compared to the nVP subjects' arms. Differences in neutralization titers between arms for single variants were statistically highly significant (p < 0.001), except for the differences between titers against the Alpha variant in the nVP and in VP groups, which were also statistically significant (p < 0.05). Within the nVP group, the number of subjects with an absence of neutralizing antibodies was high. The presence of higher titers in patients with a complete primary cycle compared to patients who had recovered from infection suggested the better efficacy of artificial immunization compared to natural immunization, and this further encourages the promotion of vaccination even in subjects with previous infections. [ABSTRACT FROM AUTHOR]

While new vaccines for SARS-CoV-2 are authorized based on neutralizing antibody (nAb) titer against emerging variants of concern, an analogous pathway does not exist for preventative monoclonal antibodies. In this work, nAb titers were assessed as correlates of protection against COVID-19 in the casirivimab + imdevimab monoclonal antibody (mAb) prevention trial (ClinicalTrials.gov #NCT4452318) and in the mRNA-1273 vaccine trial (ClinicalTrials.gov #NCT04470427). In the mAb trial, protective efficacy of 92% (95% confidence interval (CI): 84%, 98%) is associated with a nAb titer of 1000 IU50/ml, with lower efficacy at lower nAb titers. In the vaccine trial, protective efficacies of 93% [95% CI: 91%, 95%] and 97% (95% CI: 95%, 98%) are associated with nAb titers of 100 and 1000 IU50/ml, respectively. These data quantitate a nAb titer correlate of protection for mAbs benchmarked alongside vaccine induced nAb titers and support nAb titer as a surrogate endpoint for authorizing new mAbs. Here the authors assess neutralizing antibody (nAb) levels as correlate of protection in a monoclonal antibody prevention trial and a vaccine trial for COVID-19 and show that nAb titers correlate with clinical protection against COVID-19 supporting nAb titer as a surrogate endpoint for authorization of monoclonal antibodies. [ABSTRACT FROM AUTHOR]

Objectives: Recently, a number of studies have explored the possible attenuation of the immune response by disease-modifying antirheumatic drugs (DMARDs) in patients with rheumatoid arthritis (RA). Our study objective was to investigate the presumed attenuated humoral response to vaccination against SARS-CoV-2 in patients with RA treated with Janus kinase (JAK) inhibitors with or without methotrexate (MTX). The immune responses were compared with controls without RA. Method: The humoral vaccination response was evaluated by determining titres of neutralising antibodies against the S1 antigen of SARS-CoV-2. One hundred and thirteen fully vaccinated individuals were included at 6 ± 1 weeks after second vaccination (BioNTech/Pfizer (69.9%), AstraZeneca (21.2%), and Moderna (8.9%)). In a cross-sectional and single-centre study design, we compared titres of neutralising antibodies between patients with (n = 51) and without (n = 62) medication with JAK inhibitors. Results: Treatment with JAK inhibitors led to a significantly reduced humoral response to vaccination (P = 0.004). A maximum immune response was seen in 77.4% of control patients, whereas this percentage was reduced to 54.9% in study participants on medication with JAK inhibitors (effect size d = 0.270). Further subanalyses revealed that patients on combination treatment (JAK inhibitors and MTX, 9 of 51 subjects) demonstrated an even significantly impaired immune response as compared to patients on monotherapy with JAK inhibitors (P = 0.028; d = 0.267). Conclusions: JAK inhibitors significantly reduce the humoral response following dual vaccination against SARS-CoV-2. The combination with MTX causes an additional, significant reduction in neutralising IgG titres. Our data suggest cessation of JAK inhibitors in patients with RA in the context of vaccination against SARS-CoV-2. Key Points • It was shown that DMARD therapy with JAK inhibitors in patients with rheumatoid arthritis leads to an attenuation of the humoral vaccination response against SARS-CoV-2. • The effect under medication with JAK inhibitors was significant compared to the control group and overall moderate. • The combination of JAK inhibitors with MTX led to an additive and significant attenuation of the humoral response. [ABSTRACT FROM AUTHOR]

Successful vaccination (adequate elevation of anti-spike protein antibodies) is attributed with sufficient protection against a severe course of coronavirus disease 2019 (COVID-19). For patients with chronic inflammatory diseases (CID) and immunosuppression the success of vaccination is an ongoing scientific discourse. Therefore, we evaluated the antibody titer against the S1 antigen of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) 2 weeks after complete immunization in patients with an underlying neuromuscular disease (NMD), who presented to our neurological day clinic and outpatient department for regular infusions of immunoglobulins. The data show that patients with chronic autoimmune NMD and simultaneous immunosuppressive or immune modulating treatment show an antibody response after vaccination with both mRNA and vector vaccines. In comparison to healthy subjects there is a comparable number of seroconversions due to the vaccination. A correlation between immunoglobulin dose and vaccination response could not be found; however, in contrast, there was a significant reduction of specific antibody synthesis, especially for the combination of mycophenolate mofetil (MMF) and prednisolone. [ABSTRACT FROM AUTHOR]

OBJECTIVES To compare initial titers, duration, and residual clinical protection of passively transferred bovine respiratory syncytial virus (BRSV) nasal immunoglobulin (Ig) G-1 and IgA, and serum neutralizing (SN) antibodies. ANIMALS 40 three-month-old beef steers born either to unvaccinated or vaccinated cows. PROCEDURES During the last trimester of gestation, cows were assigned randomly to either vaccinated or unvaccinated groups. Calves were grouped on the basis of whether they nursed colostrum from unvaccinated dams (NO-VACC group; n = 20) versus dams vaccinated with 2 doses of an inactivated BRSV vaccine (VACC group; n = 20). At 3 months of age, calves were challenged with BRSV. Respiratory signs were scored. Nasal BRSV IgG-1 and IgA and SN antibodies were compared before and after the challenge. The presence of BRSV in nasal secretions was evaluated by reverse transcription-PCR assays. RESULTS Respiratory scores after BRSV challenge were similar between treatment groups. Nasal BRSV IgG-1 and SN antibodies were significantly greater in VACC calves at 48 hours of life; however, by 3 months of age, titers had decayed in both groups. Nasal BRSV IgA titers were minimal after colostrum intake and before the BRSV challenge, and increased in both groups after the challenge. The NO-VACC group had a significantly greater probability of shedding BRSV compared with VACC calves. CLINICAL RELEVANCE At 3 months of age, titers of passively transferred BRSV antibodies in VACC and NO-VACC calves had decayed to nonprotective levels. Calves born to vaccinated dams had a decreased probability of BRSV shedding; however, this was not related to differences in SN or nasal BRSV antibody titers. [ABSTRACT FROM AUTHOR]

Background: Up to now, information on the levels of maternally-derived antibodies (MDA) against PCV-2 in suckling piglets born to sows vaccinated with different strategies is scarce in the literature. In the present observational study, the PCV-2-specific MDA titres from piglets from 109 farms (thirty 3-day-old and thirty 21-day-old piglets per farm) across four different European countries (France n = 30, Germany n = 27, Italy n = 22 and Spain n = 30) using different sow vaccination strategies (during gestation, as a gilt, as a piglet or never) were assessed. Results: In all four countries, mean log PCV-2 MDA titres were higher in 3-day-old piglets than in the 3-week-old ones, being significant in most of all the comparisons performed. Within each country, the highest PCV-2-specific MDA titres were observed in the 3-day-old piglets born to sows vaccinated during gestation. Indeed, in the four countries, more than 60% of this subpopulation (3-day-old piglets from sows vaccinated during pregnancy) had the highest log PCV-2 titres detectable with the ELISA technique used in this study. The lowest MDA titres were more variable. Whereas in France and Germany the lowest titres corresponded to 21-day-old piglets born from sows vaccinated as a piglet, in Italy, they corresponded to 21-day-old piglets derived from sows vaccinated as a gilt and in Spain to 21-day-old piglets born from non-vaccinated sows. In this study, PCV-2-specific MDA titres at 3 and 21 days of age were not affected by sow parity. Conclusions: Data obtained could be considered as a European global overview of PCV-2-specific MDA titres present in the pre-vaccinated piglet populations in different European countries, with titres tending to be higher in younger piglets, but with values variable among countries and sow vaccination strategies. [ABSTRACT FROM AUTHOR]

In this study, the duration of immunity following a single-dose vaccination using an attenuated live goatpox vaccine (GTPV/Uttarkashi/1978 strain) was evaluated in goatpox-seronegative goats for 52 months. Long-term immunity was evaluated by clinical protection upon virulent virus challenge and serum neutralization assay applied to serum samples. The rise in the level of GTPV-specific antibodies was found to reach a maximum at 21 days post-vaccination, and these antibodies were maintained for 1 to 2 years after immunization, with a steady decline. Upon virulent virus challenge at 12, 24, 42, and 52 months post-vaccination, protection in all the vaccinated animals was evident (100%), whereas, the control animals developed severe clinical disease. This is the first time that the long-term immunity of a live goatpox vaccine has been investigated up to 52 months after vaccination in goats by virulent virus challenge and demonstration of serum neutralization titres. This vaccine has immense potential for controlling and eradicating goatpox from an enzootic region. [ABSTRACT FROM AUTHOR]

Background: IgG anti-spike (S) antibodies arise after SARS-CoV-2 infection as well as vaccination. Levels of IgG anti-S are linked to neutralizing antibody titers and protection against (re)infection. Methods: We measured IgG anti-S and surrogate neutralizing antibody kinetics against Wild Type (WT) and 4 Variants of Concern (VOC) in health care workers (HCW) 3 and 10 months after natural infection ("infection", n=83) or vaccination (2 doses of BNT162b2) with ("hybrid immunity", n=17) or without prior SARS-CoV-2 infection ("vaccination", n=97). Results: The humoral immune response in the "vaccination" cohort was higher at 3 months, but lower at 10 months, compared to the "infection" cohort due to a faster decline. The "hybrid immunity" cohort had the highest antibody levels at 3 and 10 months with a slower decline compared to the "vaccination" cohort. Surrogate neutralizing antibody levels (expressed as %inhibition of ACE-2 binding) showed a linear relation with log10 of IgG anti-S against WT and four VOC. IgG anti-S corresponding to 90% inhibition ranged from 489 BAU/mL for WT to 1756 BAU/mL for Beta variant. Broad pseudoneutralization predicted live virus neutralization of Omicron BA.1 in 20 randomly selected high titer samples. Conclusions: Hybrid immunity resulted in the strongest humoral immune response. Antibodies induced by natural infection decreased more slowly than after vaccination, resulting in higher antibody levels at 10 months compared to vaccinated HCW without prior infection. There was a linear relationship between surrogate neutralizing activity and log10 IgG anti-S for WT and 4 VOC, although some VOC showed reduced sensitivity to pseudoneutralization. [ABSTRACT FROM AUTHOR]

[Display omitted] • Two-stage seeding strategy and its multi-response optimization. • Developed strategy for improved xylitol titer and yield at 24 h lesser time. • 1.7- fold increase in volumetric productivity. • XR activity improved by 1.67-folds, with 1.3-fold decrease in XDH activity. The aim was to develop a two-stage seeding strategy and its optimization to enhance the conversion of xylose to xylitol by Debaryomyces nepalensis NCYC 3413. To develop efficient seed, multi-response optimization was employed to obtain optimal inoculum age and volume where xylitol concentration, yield and productivity were maximized. The optimal conditions of inoculation age and volume were 5.86 h and 11.66 % (v/v), respectively. Maximized results were observed at 48 h as compared to 72 h pre-optimization. Xylitol concentration slightly improved from 56 g/L to 59.71 g/L (p -value = 0.043). Yield improved from 0.56 g/g to 0.66 g/g (p -value = 0.044), whereas, productivity showed a significant increase from 0.76 g/L.h to 1.24 g/L.h (p -value = 0.008). Xylose Reductase activity improved by 1.67-folds and Xylitol Dehydrogenase activity decreased by 1.3 folds. This work suggests a simple inoculum strategy that could expedite the enzyme system required for xylitol production, enabling a 1.7-fold increase in productivity. [ABSTRACT FROM AUTHOR]

Despite the remarkable efficacy of currently approved COVID-19 vaccines, there are several opportunities for continued vaccine development against SARS-CoV-2 and future lethal respiratory viruses. In particular, restricted vaccine access and hesitancy have limited immunization rates. In addition, current vaccines are unable to prevent breakthrough infections, leading to prolonged virus circulation. To improve access, a subunit vaccine with enhanced thermostability was designed to eliminate the need for an ultra-cold chain. The exclusion of infectious and genetic materials from this vaccine may also help reduce vaccine hesitancy. In an effort to prevent breakthrough infections, intranasal immunization to induce mucosal immunity was explored. A prototype vaccine comprised of receptor-binding domain (RBD) polypeptides formulated with additional immunoadjuvants in a chitosan (CS) solution induced high levels of RBD-specific antibodies in laboratory mice after 1 or 2 immunizations. Antibody responses were durable with high titers persisting for at least five months following subcutaneous vaccination. Serum anti-RBD antibodies contained both IgG1 and IgG2a isotypes suggesting that the vaccine induced a mixed Th1/Th2 response. RBD vaccination without CS formulation resulted in minimal anti-RBD responses. The addition of CpG oligonucleotides to the CS plus RBD vaccine formulation increased antibody titers more effectively than interleukin-12 (IL-12). Importantly, generated antibodies were cross-reactive against RBD mutants associated with SARS-CoV-2 variants of concern, including alpha, beta and delta variants, and inhibited binding of RBD to its cognate receptor angiotensin converting enzyme 2 (ACE2). With respect to stability, vaccines did not lose activity when stored at either room temperature (21-22°C) or 4°C for at least one month. When delivered intranasally, vaccines induced RBD-specific mucosal IgA antibodies, which may protect against breakthrough infections in the upper respiratory tract. Altogether, data indicate that the designed vaccine platform is versatile, adaptable and capable of overcoming key constraints of current COVID-19 vaccines. [ABSTRACT FROM AUTHOR]

Salmonella Heidelberg (SH) has been reported in broiler flocks of many countries. The ability of some SH strains of poultry origin to cause foodborne infections in humans is a concern. Usually, infection of broiler flocks by SH occurs in the first days of life. Therefore, control measures should start early post-hatch. One of the strategies is to generate high titres of anti-Salmonella IgY in breeders by using bacterins to provide passive immunity to their progeny. In this study, three broiler breeder flocks were submitted to three Salmonella vaccination regimes (two doses of vaccine 1, two doses of vaccine 2, and non-vaccinated). When breeders were 30 or 55 weeks old, some of their offspring were separated and challenged with an SH strain at 3 days of age. Dissemination to organs, caecal colonization, and faecal excretion of SH were evaluated over a period of 20 days. Chicks from vaccinated 30-week-old breeders presented lower amounts of SH in caecal contents at 1, 3, and 6 days post-infection, correlating with high titres of maternal anti-Salmonella IgY in their yolk. In contrast, there were no differences in counts of SH in caecal contents of chicks when their parents were 55 weeks old and titres of IgY were reduced. Amounts of SH in liver and spleen were low and there were no differences among birds throughout the experiment. Progeny from a 30-week-old flock vaccinated with vaccine 1 also showed lower SH faecal shedding than the remaining birds. Apparently, the maternal IgY was associated with reduction in intestinal infection by SH. Progeny from vaccinated 30-week-old breeders presented less SH in caecal content compared to the control. High titres of maternal anti-Salmonella IgY could be associated with lower SH faecal shedding. [ABSTRACT FROM AUTHOR]

Background and aims: Patients with chronic kidney disease (CKD) on maintenance hemodialysis (MHD) have a higher prevalence of Hepatitis B. Hepatitis B is preventable by vaccination, however, the seroconversion response is less effective in patients of CKD. Since diabetes is an important cause of CKD, this study aimed to compare seroconversion rates after Hepatitis B vaccination in normal individuals, patients with non-diabetic CKD (NDCKD) on MHD and patients with diabetic chronic kidney disease (DCKD) on MHD. We also aimed to determine whether an association existed between seroconversion rates and the duration of diabetes. Materials and methods: This was a case-control study conducted on the following subjects who had completed the Hepatitis B immunization schedule--normal subjects, patients with NDCKD stage 5, and patients with DCKD stage 5 on MHD. Anti-HBS levels were measured in the three groups and seroconversion rates were measured and compared. Result: Of 132 subjects, 44 each were normal controls, NDCKD, and DCKD on MHD. 100% of normal individuals seroconverted. Among the subjects on MHD, more NDCKD (72.7%) seroconverted when compared to DCKD (52.3%, p-value 0.048). Non-responders had diabetes for more than 10 years. Conclusion: Among patients on MHD, those with DCKD have lower rates of seroconversion compared to those with NDCKD. Older age, less dialysis, and longer duration of diabetes adversely influenced seroconversion. [ABSTRACT FROM AUTHOR]

Health care workers (HCW) are a high-risk population for Hepatitis B infection. Hepatitis B vaccine which is 95% effective confers long-term protection and anti-HBs titre is a marker for protective immune response. Our objective was to assess the status of hepatitis B vaccination and to evaluate the anti-HBsAg titres among health care workers in a tertiary care hospital, Tamil Nadu. It was an observational study conducted among 610 Health care workers in a tertiary care teaching hospital from June to December 2018 after obtaining clearance from IEC. Workers were assessed for their HBV vaccination status and for their anti-HBsAg titre after getting informed consent. The antibody titres were measured using CLIA (chemiluminescent Immunoassay) supplied by Abbott diagnostics. The data was entered and analyzed using a Microsoft Excel sheet. In our study, 80.5% were fully vaccinated, 18.5% of them were defaulters which comprised the HCW with 2 doses and 1 dose of vaccine and 0.9% were not vaccinated. In the fully vaccinated group, 37% showed Anti HBs titres of 10-100 mIU/ml, 59.2% showed the titre of > 100 mIU/ml and 3.6% did not show the protective antibody titre (<10 mIU/ml ). The 3.6% who did not show protective antibody titre were given the booster dose of vaccine. Among those who received a booster dose, 61.1% responded with the titre of 10-100 mIU/ml and 22.2% responded with the titre of > 100 mIU/ ml and 16.6% did not respond even with the booster dose. In the defaulters 86.7% had titres < 10 mIU/ml, 9.7% had titres of 10 mIU/ml and 3.6% had titres > 10 mIU/ml. In the non vaccinated group all had titres < 10 mIU/ml. The present study emphasizes the importance of screening of anti-HBsAg titres to be made mandatory for all the health care workers along with HBV Vaccination. [ABSTRACT FROM AUTHOR]

Levels of 50% neutralizing titer (NT50) reflect the a vaccine-induced humoral immunity after the vaccination against the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Measurements of NT50 are difficult to implement in large quantities. A high-throughput laboratory test is expected for determining the level of herd immunity against SARS-CoV-2. We analyzed samples from 168 Japanese healthcare workers who had completed two doses of the BNT162b2 vaccine. We analyzed immunoglobulin G (IgG) index values against spike protein (SP) using automated chemiluminescent enzyme immunoassay system AIA-CL and analyzed the background factors affecting antibody titer. SP IgG index was compared with 50% neutralization titers. The median SP IgG index values of the subjects (mean age = 43 years; 75% female) were 0.1, 1.35, 60.80, and 97.35 before and at 2, 4, and 6 weeks after the first dose, respectively. At 4 and 6 weeks after the first dose, SP IgG titers were found to have positive correlation with NT50 titer (r = 0.7535 in 4 weeks; r = 0.4376 in 6 weeks). Proportions of the SP IgG index values against the Alpha, Beta, Gamma, and Delta variants compared with the original strain were 2.029, 0.544, 1.017, and 0.6096 respectively. Older age was associated with lower SP IgG titer index 6 weeks after the first dose. SP IgG index values were rised at 3 weeks after two doses of BNT162b2 vaccination and have positive correlation with NT50. SP IgG index values were lower in the older individuals and against Beta and Delta strain. [ABSTRACT FROM AUTHOR]

Keywords: antibodies; vaccination; SARS-CoV-2 EN antibodies vaccination SARS-CoV-2 356 359 4 02/07/22 20220201 NES 220201 Sera of vaccines were assessed by surrogate virus neutralization tests for their capacity to neutralize the SARS-CoV-2 Delta variant. Interestingly, of all vaccination regimens tested in the present study, homologous immunization with the MOD vaccine appears to induce the highest levels of antibodies able to neutralize the Delta variant of SARS-CoV-2 and that even heterologous immunization with ChAd/MOD induces titers similar to those found after vaccination with BNT/BNT. Robust induction of neutralizing antibodies against the SARS-CoV-2 Delta variant after homologous Spikevax or heterologous Vaxzevria-Spikevax vaccination In contrast, after heterologous immunization with MOD, the median RBD-blocking titers increased to 1/540 and 1/180 at day 14 and day 28 after boosting, respectively, indicating a high immunogenicity of this mRNA vaccine for induction of neutralizing antibodies against the Delta variant (Fig. [Extracted from the article]

The immune response promoted by SARS-CoV-2 vaccination is relevant to develop novel vaccines and optimized prevention strategies. We analyzed the adaptive immunity in healthy donors (HD) and convalescent individuals (CD), before and after administering BNT162b2 vaccine. Our results revealed specific changes in CD4+ T cell reactivity profile in vaccinated HD and CD, with an increase in S1 and S2 positive individuals, proportionally higher for S2. On the contrary, NCAP reactivity observed in HD and CD patients was no longer detectable after vaccination. Despite the substantial antibody response in CD, MPro-derived peptides did not elicit CD4+ lymphocyte activation in our assay in either condition. HD presented an increment in anti-S and anti-RBD IgG after first dose vaccination, which increased after the second vaccination. Conversely, anti-S and anti-RBD IgG and IgA titers increased in already positive CD after first dose administration, remaining stable after second dose inoculation. Interestingly, we found a strong significant correlation between S1-induced CD4+ response and anti-S IgA pre-vaccination, which was lost after vaccine administration. [ABSTRACT FROM AUTHOR]

Diagnosis and surveillance of pathogenic Leptospira is difficult as organisms may be intermittently shed and in small numbers. Therefore, serologic testing by the microscopic agglutination test (MAT) is the primary screening method for leptospirosis. While a MAT titer ≥1:100 is considered to be a positive result, interpretation is complicated by the use of commercial vaccines in pigs. Most guidelines for interpretation of MAT titers in pigs were published in the 1970's and 1980's, prior to the development of the current multivalent vaccines. We evaluated MAT titers in routinely vaccinated healthy research pigs compared to their unvaccinated cohorts. Our study confirmed previous reports that the Pomona serovar elicits minimal antibody response even after a second booster 6 months after initial vaccination. However, MAT titers of ≥1:3,200 were detected as early as 4 weeks post initial vaccination for serovars Bratislava and Icterohaemorrhagiae and remained as high as ≥1:1,600 prior to booster at 24 weeks post vaccination. Our study determined that high levels of MAT titers can occur from vaccination alone and high titers are not necessarily indicative of infection. Therefore, the interpretation of MAT titers as indicators of Leptospira infection should be readdressed. [ABSTRACT FROM AUTHOR]

Effective parenteral vaccines are available to control rabies in dogs. While such vaccines are successfully used worldwide, the period between vaccine boosters required to guarantee protection of the population against rabies varies between vaccines and populations. In Flores Island, Indonesia, internationally and locally produced rabies vaccines are used during annual vaccination campaigns of predominantly free-roaming owned domestic dogs. The study objective was to identify the duration of the presence and factors associated with the loss of adequate level of binding antibodies (≥0.5 EU/ml) following rabies vaccination in a domestic dog population on Flores Island. A total of 171 dogs that developed an antibody titre higher or equal to 0.5 EU/ml 30 days after vaccination (D30), were repeatedly sampled at day 90, 180, 270, and 360 after vaccination. On the day of vaccination (D0), an interview was performed with dog owners to collect information on dog characteristics (age, sex, body condition score (BCS)), history of rabies vaccination, kind of daily food, frequency of feeding, and origin of the dog. Serum samples were collected and the level of antibodies was quantitatively assessed using ELISA tests. Dogs were categorized as having an adequate level of binding antibodies (≥0.5 EU/ml) or inadequate level of binding antibodies (<0.5 EU/ml) at each time points examined. A total of 115, 72, 23, and 31 dogs were sampled at D90, D180, D270, and D360, respectively, with the highest proportion of antibodies ≥ 0.5 EU/ml (58%, 95% CI, 49–67%) at D90, which reduced gradually until D360 (35%, 95% CI, 19–52%). Multivariable logistic regression models showed that loss of adequate level of binding antibodies is significantly associated with dogs having no history of vaccination or vaccination applied more than 12 months before D0, being less than 12 months of age, and having a poor BCS. These results highlight the importance of BCS regarding the immune response duration and provide insights into frequency of vaccination campaigns required for the internationally available vaccine used on Flores Island. For dogs without vaccination history or vaccination being applied more than 12 months before D0, a booster is recommended within 3 months (a largest drop of antibodies was detected within the first 90 days) after the first vaccination to guarantee measurable protection of the population that lasts at least for one year. Author summary: Rabies is a zoonotic disease, caused by a lyssavirus, resulting in thousands of deaths every year, particularly in low-resource endemic regions in Asia and Africa. High quality rabies vaccines have been available since decades to guarantee protection of the dog population against rabies. Furthermore, maintaining a high vaccination coverage and herd immunity until the subsequent vaccination campaign is essential for preventing circulation of rabies virus within dog populations. However, the percentage of dogs that maintain an adequate level of rabies antibodies one year after vaccination and factors influencing such a maintenance is unknown for the dog populations on Flores Island, Indonesia. This study aimed at understanding the risk factors associated with loss of adequate level of binding antibodies amongst vaccinated dogs that developed antibody titre ≥0.5 EU/ml after parenteral vaccination, following a longitudinal study over one year. The study identified body condition score of the dogs, their previous vaccination, and their age as factors that influence the maintenance of an adequate level of antibodies. For dogs without previous vaccination and vaccination being applied more than 12 months ago, a booster is recommended within 3 months after the first vaccination to guarantee an antibody levels that lasts for at least one year. In addition, a low BCS should be considered as one of the risk factors of losing measurable immunity. Therefore, improving the dogs' poor BCS should also be promoted to enhance immune response and ensure longer presence of antibodies against rabies. [ABSTRACT FROM AUTHOR]

Objectives: To elucidate veterinarians' and horse owners' perceptions towards the use of Hendra virus (HeV) antibody titre testing and how it influences veterinary advice. Methods: Six semi‐structured phone interviews were conducted with veterinarians who have submitted samples for HeV antibody titre testing. Interviews were recorded, transcribed and thematically analysed to identify and report common themes within the data. Results: Veterinarians are predominantly using the titre tests as an alternative to vaccination due to clients' fear of vaccine reactions. The high cost of titre testing, the difficulty interpreting titre results and a lack of titre test recognition by authorities were the major barriers reported to using this test. Some veterinarians detailed difficulties communicating titre test procedures and results to their clients. The majority of veterinarians accepted titres of 64 or greater as evidence of protective immunity and would rely on those results for 12 months. However, there was discrepancy of these values and the level of confidence veterinarians had in interpreting the results of HeV antibody titre tests varied. Conclusion: This study has provided an overview of the attitudes of horse owners and veterinarians towards HeV antibody titre testing. Although evidence for HeV vaccination titres as an indication of protective immunity is still inadequate, it will assist veterinarians in interpreting and communicating titre results. [ABSTRACT FROM AUTHOR]

BackgroundEfficacy of vaccines and disease activity linked to immunization are major concerns among people with multiple sclerosis (pwMS).ObjectiveTo assess antibody responses to seasonal influenza antigens and vaccine-associated neuroaxonal damage utilizing serum neurofilament light chain (sNfL) in pwMS receiving dimethyl fumarate (DMF).MethodsIn this prospective study, the 2020/2021 seasonal tetravalent influenza vaccine was administered to 20 pwMS treated with DMF and 15 healthy controls (HCs). The primary endpoints were responder rate of strain-specific antibody production (seroconversion or significant (4-fold) increase in influenza-antibody titers for ≥2/4 strains) at 30 days post-vaccination and changes in sNfL levels.ResultsAll patients treated with DMF fulfilled the responder criteria for immunization compared with 53% of the controls. However, higher proportions of HCs already had influenza-antibody titers ≥1:40 at baseline (53% vs. 41%, p = 0.174). sNfL levels were comparable among both groups at baseline and did not increase 34 days after vaccination. In addition, no clinical or radiological disease reactivation was found.ConclusionDMF-treated patients mount an adequate humoral immune response to influenza vaccines. Within the limits of the small cohort investigated, our data suggest that influenza immunization is not associated with clinical or subclinical disease reactivation.

Background: Efficacy of vaccines and disease activity linked to immunization are major concerns among people with multiple sclerosis (pwMS). Objective: To assess antibody responses to seasonal influenza antigens and vaccine-associated neuroaxonal damage utilizing serum neurofilament light chain (sNfL) in pwMS receiving dimethyl fumarate (DMF). Methods: In this prospective study, the 2020/2021 seasonal tetravalent influenza vaccine was administered to 20 pwMS treated with DMF and 15 healthy controls (HCs). The primary endpoints were responder rate of strain-specific antibody production (seroconversion or significant (4-fold) increase in influenza-antibody titers for ≥2/4 strains) at 30 days post-vaccination and changes in sNfL levels. Results: All patients treated with DMF fulfilled the responder criteria for immunization compared with 53% of the controls. However, higher proportions of HCs already had influenza-antibody titers ≥1:40 at baseline (53% vs. 41%, p = 0.174). sNfL levels were comparable among both groups at baseline and did not increase 34 days after vaccination. In addition, no clinical or radiological disease reactivation was found. Conclusion: DMF-treated patients mount an adequate humoral immune response to influenza vaccines. Within the limits of the small cohort investigated, our data suggest that influenza immunization is not associated with clinical or subclinical disease reactivation. [ABSTRACT FROM AUTHOR]

Contamination of fomites by human norovirus (HuNoV) can initiate and prolong outbreaks. Fomite swabbing is necessary to predict HuNoV exposure and target interventions. Historically, swab recovered HuNoV has been measured by molecular methods that detect viral RNA but not infectious HuNoV. The recent development of HuNoV cultivation in human intestinal enteroids (HIEs) enables detection of infectious HuNoV. It is unknown if the swabbing process and swab matrix will allow for cultivation of fomite recovered HuNoV. We used HIEs to culture swab-recovered HuNoV GII.4 Sydney from experimentally infected surfaces—a hospital bed tray (N = 32), door handle (N = 10), and sanitizer dispenser (N = 11). Each surface was swabbed with macrofoam swabs premoistened in PBS plus 0.02% Tween80. Swab eluate was tested for infectious HuNoV by cultivation in HIE monolayers. Infectious HuNoV can be recovered from surfaces inoculated with at least 105 HuNoV genome equivalents/3 cm2. In total, 57% (N = 53) of recovered swabs contained infectious HuNoV detected by HIEs. No difference in percent positive swabs was observed between the three surfaces at p = 0.2. We demonstrate that fomite swabbing can be combined with the HIE method to cultivate high titer infectious HuNoV from the environment, filling a significant gap in HuNoV detection. Currently, high titers of HuNoV are required to measure growth in HIEs and the HIE system precludes absolute quantification of infectious viruses. However, the HIE system can provide a binary indication of infectious HuNoV which enhances existing detection methods. Identification of infectious HuNoVs from swabs can increase monitoring accuracy, enhance risk estimates, and help prevent outbreaks. [ABSTRACT FROM AUTHOR]

Emerging severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants have raised concerns about resistance to neutralizing antibodies elicited by previous infection or vaccination. We examined whether sera from recovered and naïve donors, collected before and after immunizations with existing messenger RNA (mRNA) vaccines, could neutralize the Wuhan-Hu-1 and B.1.351 variants. Prevaccination sera from recovered donors neutralized Wuhan-Hu-1 and sporadically neutralized B.1.351, but a single immunization boosted neutralizing titers against all variants and SARS-CoV-1 by up to 1000-fold. Neutralization was a result of antibodies targeting the receptor binding domain and was not boosted by a second immunization. Immunization of naïve donors also elicited cross-neutralizing responses but at lower titers. Our study highlights the importance of vaccinating both uninfected and previously infected persons to elicit cross-variant neutralizing antibodies. [ABSTRACT FROM AUTHOR]

Vaccination for SARS-CoV-2 provides significant protection against the infection in the general population. However, only limited data exist for patients with cancer under systemic therapy. Based on this, our site has initiated a study evaluating safety and efficacy of SARS-CoV-2 vaccination in patients with solid and hematological malignancies under several systemic therapies. The initial results of the cohort of 59 patients receiving Immune Checkpoint Inhibitors are presented here. Despite no new safety issues have been noticed, the levels of SARS-CoV-2 neutralizing antibodies are significantly lower in comparison to matched healthy volunteers up to day 22 post the first dose. These results should be taken into consideration for the patients under treatment. [ABSTRACT FROM AUTHOR]

Fewer than half of organ transplant recipients receiving antimetabolite therapies developed antibodies after 2 doses of mRNA vaccine ([2]). Patients with inflammatory bowel disease (IBD) receiving infliximab were less likely than those receiving vedolizumab to develop antibodies after 1 dose of BNT162b2 (Pfizer-BioNTech) or ChAdOx1 nCoV-19 (Oxford-AstraZeneca) vaccine ([3]), although other researchers have shown that seroconversion occurs in most patients with IBD after 2 doses of mRNA vaccine ([4], [5]). I Background: i The effects of immunosuppression on responses to SARS-CoV-2 vaccine are unclear given that patients receiving immune-modifying therapies, who constitute 2.8% of commercially insured adults, were underrepresented in vaccine trials ([1]). [Extracted from the article]

In vitro determination of severe acute respiratory syndrome coronavirus 2 neutralizing antibodies induced in serum samples from recipients of the CoronaVac vaccine showed a short protection period against the original virus strain and limited protection against variants of concern. These data provide support for vaccine boosters, especially variants of concern circulate. [ABSTRACT FROM AUTHOR]

One of the major goals of vaccination is to prepare the body to rapidly secrete specific Abs during an infection. Assessment of the vaccine quality is often difficult to perform, as simple measurements like Ab titer only partly correlate with protection. Similarly, these simple measurements are not always sensitive to changes in the preceding immunization scheme. Therefore, we introduce in this paper a new, to our knowledge, method to assay the quality of immunization schemes for mice: shortly after a recall with pure Ag, we analyze the frequencies of IgG-secreting cells (IgG-SCs) in the spleen, as well as for each cells, the Ag affinity of the secreted Abs. We observed that after recall, appearance of the IgG-SCs within the spleen of immunized mice was fast (<24 h) and this early response was free of naive IgG-SCs. We further confirmed that our phenotypic analysis of IgG-SCs after recall strongly correlated with the different employed immunization schemes. Additionally, a phenotypic comparison of IgG-SCs presented in the spleen during immunization or after recall revealed similarities but also significant differences. The developed approach introduced a novel (to our knowledge), quantitative, and functional highly resolved alternative to study the quality of immunizations. [ABSTRACT FROM AUTHOR]

Background: A previous phase 2 study demonstrated the immunogenicity of a single dose of meningococcal A, C, W, Y-tetanus toxoid conjugate (MenACWY-TT) or polysaccharide (MenACWY-PS) vaccine for up to 5 years in individuals aged 11-55 years. This follow-up study evaluated long-term antibody persistence up to 10 years and the immunogenicity and safety of a single MenACWY-TT booster dose given 10 years after primary vaccination.Methods: Blood draws were conducted annually in Years 7-10. At Year 10, all subjects received a MenACWY-TT booster dose. Blood was drawn at 1 month and safety data were collected ≤6 months postbooster. Study endpoints included immunogenicity during the persistence phase (primary), and immunogenicity and safety during the booster phase (secondary). Statistical analyses were descriptive.Results: A total of 311 subjects were enrolled in the persistence phase (MenACWY-TT, 235; MenACWY-PS, 76); 220 were enrolled in the booster phase (MenACWY-TT, 164; MenACWY-PS, 56). Descriptive analyses indicated that at Years 7-10, the percentages of subjects achieving serum bactericidal antibody assay using baby rabbit complement (rSBA) titers ≥1:8 and ≥1:128 were higher for serogroups A, W, and Y in the MenACWY-TT versus MenACWY-PS group; percentages were similar across groups for serogroup C. rSBA geometric mean titers (GMTs) for serogroups A, W, and Y were higher in the MenACWY-TT group and slightly higher in the MenACWY-PS group for serogroup C. One month postbooster, all primary MenACWY-TT and ≥98.1% of primary MenACWY-PS recipients had rSBA titers ≥1:8. For all serogroups, rSBA GMTs postbooster were higher in the MenACWY-TT versus MenACWY-PS group. Most local and general reactogenicity events were similar between groups and mild to moderate in severity. Adverse events at 1 month postbooster were 9.1% for the MenACWY-TT and 3.6% for the MenACWY-PS groups; all were nonserious.Conclusions: Immune responses to a single MenACWY-TT primary dose administered at age 11-55 years persisted in >70% of individuals evaluated at Years 7-10. A MenACWY-TT booster dose administered at Year 10 was safe and immunogenic with no new safety signals observed. These results provide important insights regarding long-term protection from primary vaccination and the benefits of booster dosing.Trial Registration: Clinicaltrials.gov, NCT01934140. Registered September 2013. [ABSTRACT FROM AUTHOR]

Background Although high-dose (HD) vaccines have been reported to stimulate higher antibody responses compared with standard-dose (SD) influenza vaccines, there have been limited studies on the impact of frailty on such responses. Methods We conducted a randomized, double-blind trial (2014/2015 to 2017/2018) of SD versus HD trivalent split-virus vaccine (Fluzone) in 612 study participants aged 65+ over 4 influenza seasons. Hemagglutination inhibition antibody titers for influenza H1N1, H3N2, and B vaccine subtypes were measured at baseline and at 4, 10, and 20 weeks postvaccination and frailty was measured using a validated frailty index. Results Geometric mean antibody titers were significantly higher in HD compared with SD vaccine recipients for all influenza subtypes at all time points postvaccination. However, frailty was positively correlated with 4-week titers and was associated with increased odds of being a vaccine responder. For influenza A subtypes, this was mostly limited to HD recipients. Conclusions Frailty was associated with higher titers and increased antibody responses at 4 weeks after influenza vaccination, which was partially dependent on vaccine dosage. Chronic inflammation or dysregulated immunity, both of which are commonly observed with frailty, may be responsible, but it requires further investigation. [ABSTRACT FROM AUTHOR]

Cladribine (CLAD) is a lymphodepleting agent approved for active relapsing multiple sclerosis (MS). The impact of CLAD on the adaptive humoral immune system has not sufficiently been studied. This study aimed to assess the influence of CLAD treatment on specific antibody titers to common pathogens. We included 18 MS patients treated with CLAD. Serum IgG antibody levels to measles, mumps, rubella, hepatitis B and varicella zoster virus (VZV), as well as diphtheria and tetanus toxins, were measured prior to the initiation of treatment and at 12 and 24 months after first CLAD administration. Moreover, specimens were longitudinally analyzed regarding absolute blood concentrations of IgG and main lymphocyte subsets. No reduction in antibody levels against measles, mumps, rubella, VZV, hepatitis B, diphtheria toxin and tetanus toxin associated with CLAD treatment was observed. Loss of seroprotection occurred in p < 0.00001 and p < 0.000001). This study suggests that CLAD does not interfere with the pre-existing humoral immunologic memory in terms of pathogen-specific antibody titers.

Highlights • Complications caused by the VZV virus (high-risk population). • Interest of post-exposure prophylaxis. • Impact of routine vaccination on the incidence, complications, and avoided costs. • One dose versus two doses of vaccine. • Combined vaccine: tolerability and immunogenicity. • Impact on the incidence of herpes zoster infection. Abstract Despite its benign characteristics, chickenpox is a childhood disease responsible for complications and deaths, particularly in the high-risk population. VariZIG®, not commercialized in France, is a good alternative for seronegative individuals exposed to the virus and not eligible for vaccination. The efficacy of routine vaccination has been demonstrated with a decrease in chickenpox incidence and with the development of herd immunity. Over time, the protective antibody titer of vaccinated people decreases and can be maintained by two doses of the vaccine. A tetravalent measles-mumps-rubella-chickenpox vaccine, used in the United States, has a good tolerability in spite of the occurrence of fever and febrile seizures. Routine vaccination would contribute to make savings in France, by reducing direct and indirect costs of chickenpox. [ABSTRACT FROM AUTHOR]

Summary: Pregnant women and infants are at an increased risk of severe disease after influenza infection. Maternal immunization is a potent tool to protect both these at‐risk groups. While the primary aim of maternal influenza vaccination is to protect the mother, a secondary benefit is the transfer of protective antibodies to the infant. A recent study using the tetanus, diphtheria and acellular pertussis (Tdap) vaccine indicated that children born to mothers immunized in the second trimester of pregnancy had the highest antibody titres compared to children immunized in the third trimester. The aim of the current study was to investigate how the timing of maternal influenza immunization impacts infant antibody levels at birth. Antibody titres were assessed in maternal and cord blood samples by both immunoglobulin (Ig)G‐binding enzyme‐linked immunosorbent assay (ELISA) and haemagglutination inhibition assay (HAI). Antibody titres to the H1N1 component were significantly higher in infants born to mothers vaccinated in either the second or third trimesters than infants born to unvaccinated mothers. HAI levels in the infant were significantly lower when maternal immunization was performed less than 4 weeks before birth. These studies confirm that immunization during pregnancy increases the antibody titre in infants. Importantly, antibody levels in cord blood were significantly higher when the mother was vaccinated in either trimesters 2 or 3, although titres were significantly lower if the mother was immunized less than 4 weeks before birth. Based on these data, seasonal influenza vaccination should continue to be given in pregnancy as soon as it becomes available. Maternal immunization is a potent tool to protect pregnant women and their newborn infants against influenza. In this study we investigated the effect of different timing of influenza immunization in pregnancy on the transfer of antibody to the infant. Antibody levels in cord blood were significantly higher when the mother was vaccinated in either trimesters 2 or 3, although titres were significantly lower if the mother was immunized less than 4 weeks before birth. [ABSTRACT FROM AUTHOR]

Abstract Background Global elimination of vaccine preventable diseases, such as measles, mumps and rubella is a priority. Many countries have reported diminishing of antibody titres against these diseases among young population as immunization coverage of adolescents and adults in not monitored. The objective of this study was to determine the susceptibility against measles, mumps and rubella among young adults. Methods In this cross-sectional study serological evidence of susceptibility to measles, mumps and rubella was determined by qualitative detection of IgG antibody titres by commercially available enzyme linked florescence assay (VIDAS, bioMerieux) in serum samples young adults. Results A total of 335 young individuals (mean age: 20.54 ± 1.37 years) participated voluntarily between May 2017 to September 2018, of which 183 (54.63%) were males. Seroprotection against measles, mumps and rubella were 87.16%, 82.69% and 79.10% respectively. Conclusion Serological surveillance is important to monitor immune status in population. Susceptibility of young adults to measles, mumps, and rubella indicates need for booster vaccination. With the recent launch of measles-rubella vaccination campaign in India, country specific data will be required to plan periodicity of such campaign, which in turn would be based on accumulation of susceptible individuals in a community. Lastly, inclusion of mumps vaccine in the national universal immunization program needs consideration. [ABSTRACT FROM AUTHOR]

Canine core vaccine titer screenings are becoming increasingly popular in veterinary practice as a tool to guide vaccination decisions, despite a lack of supportive, peer-reviewed evidence-based literature. Additionally, it has been suggested that the canine core vaccine duration of host protective immunity can persist past the currently recommended vaccination interval. Thus, this study evaluated serum antibody titers against three core antigens in dogs with known vaccination histories and lifestyles, analyzing the effect of life stage, exposure risk, and time since last vaccination (TSLV). Clinically healthy dogs (n = 188) presenting to the primary care services of three colleges of veterinary medicine were selected to represent a variety of ages, breeds, and vaccination history. Serum antibody titers for canine parvovirus (CPV), canine distemper virus (CDV), and canine adenovirus-2 (CAV2) were measured via virus neutralization and hemagglutination inhibition. CAV2 and CPV titers decreased, while CDV titers had a decreasing trend with increasing time since last vaccination or vaccination interval. When assessing circulating antibody levels historially associated with protective immunity across various vaccination intervals, 62% (95%CI 36–82%; 8/13) of dogs had positive titers for CDV 5 years post last vaccination, while 92% (95%CI 67–99%; 12/13) of dogs were positive for CAV2 and CPV. Both advanced age and life stage were associated with lower titers and thus, identify a canine population cohort likely at higher disease risk. The results of this study revealed that patient duration of core vaccine-mediated immunity changes with a number of variables, with animal aging and time since vaccination influencing host humoral immunity. This provides further support for the performance of canine core antibody titers to assess whether a vaccine booster and/or specific type of booster is warranted. [ABSTRACT FROM AUTHOR]

Background: Hepatitis B virus (HBV) infection is the most common cause of liver disease in endemic areas such as South Korea. After HBV vaccination, hepatitis B surface antibody (HBsAb) titers gradually decrease. Trends in HBsAb titers have not been evaluated among children in South Korea over the past decade.Methods: We screened 6155 patients (aged 7 months to 17 years) who underwent HBV antigen/antibody testing at Chung-Ang University Hospital from May 2012 to April 2015. Titer criteria were defined as follows: positive, titer ≥100 IU/L; weakly positive, titer 10-99 IU/L; and negative, titer <10 IU/L. We also compared titers before and 1 month after a single booster vaccination.Results: Of the 5655 patients included, 3016 were male and 5 (0.09%) tested positive for HBV surface antigen. A marked reduction in antibody titer was observed until 4 years of age. Thereafter, the titers showed fluctuating decreases. HBsAb titers reached their lowest levels by 14 years of age. After 7 years of age, 50% of patients tested negative for HBsAb. Simple linear analysis showed that the titer reached levels of <10 IU/L and zero at 12.9 and 13.4 years of age, respectively. 1 month after a single booster vaccination was administered to those who were HBsAb-negative (n = 72), 69 children (96%) had developed antibodies while 3 (4%) remained HBsAb-negative.Conclusions: In conclusion, the continuous reduction in HBsAb titers over time and in each age group was confirmed. The titer level was shown significant decline until age 4. More than half of the sample had negative titers after age 7 years. After booster vaccination, most of child significantly increase titer level. [ABSTRACT FROM AUTHOR]

• Mumps IgG levels to vaccine and outbreak strains were reduced in the older cohorts. • Mumps-specific IgG3 levels were increased in mumps cases. • Neutralization titres were lower to the outbreak strain in all cohorts. • Mumps cases showed reduced neutralization titres compared to healthy controls. Despite widespread use of the mumps vaccine resulting in significant reduction in the incidence of symptomatic mumps infection, large outbreaks continue to occur in highly vaccinated populations. We examined the mumps-specific IgG, IgG subclasses and neutralization titres to the outbreak Genotype G5 and Jeryl Lynn vaccine (Genotype A) mumps strains. Sera from 207 individuals were classified into five distinct cohorts: healthy controls and mumps cases of 5–17 years and 18–25 years, and naturally infected individuals of 50+ years. Mumps specific IgG and IgG subclass levels were measured using modified ELISA assays with lysates and nucleoprotein antigens from both the mumps vaccine and circulating Genotype G5 strains. All sera were investigated for in vitro neutralizing antibody titres (GMT) using focus reduction neutralization assays. Data was analysed using the Kruskal-Wallis test and pairwise Wilcoxon tests. Mumps cases had higher mumps IgG levels compared to controls, to both the vaccine and outbreak strains, however levels decreased with age. Mumps IgG3 levels were significantly raised in mumps cases (p < 0.001). Neutralization titres were lower to the outbreak strain in all cohorts with titres markedly lower in the mumps cohorts compared to healthy controls. Mean GMT to the vaccine strain increased with age. The naturally infected group displayed the highest GMT to the JL vaccine and the lowest GMT to the outbreak strain. Antigenic differences between mumps vaccine strain and circulating mumps viruses decrease the cross-neutralization capacity of vaccine-induced antibodies which may play a role in breakthrough infection. [ABSTRACT FROM AUTHOR]

With the goal of developing a virus-like particle-based vaccine based on dense bodies (DB) produced by human cytomegalovirus (HCMV) infections, we evaluated scalable culture, isolation, and inactivation methods and applied technically advanced assays to determine the relative purity, composition, and immunogenicity of DB particles. Our results increase our understanding of the benefits and disadvantages of methods to recover immunogenic DB and inactivate contaminating viral particles. Our results indicate that (i) HCMV strain Towne replicates in MRC-5 fibroblasts grown on microcarriers, (ii) DB particles recovered from 2-bromo-5,6-dichloro-1-beta-D-ribofuranosyl benzimidazole riboside (BDCRB)-treated cultures and purified by tangential flow filtration (TFF-DB) or glycerol tartrate gradient sedimentation (GT-DB) constitute 92% or 98%, respectively, of all particles in the final product, (iii) epithelial cell-tropic DB particles are recovered from a single round of coinfection by AD169 and Towne strain viruses, consistent with complementation between the UL130 and UL131A expressed by these strains and restoration of gH/gL/UL128-UL131A (gH pentamer), (iv) equivalent neutralizing antibody titers are induced in mice following immunization with epithelial cell-tropic DB or gH pentamer-deficient DB preparations, (v) UV-inactivated residual virus in GT-DB or TFF-DB preparations retained immunogenicity and induced neutralizing antibody, preventing viral entry into epithelial cells, and (vi) GT-DB and TFF-DB induced cellular immune responses to multiple HCMV peptides. Collectively, this work provides a foundation for future development of DB as an HCMV-based particle vaccine. [ABSTRACT FROM AUTHOR]