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Background: Alterations in the bacteria, such as the periodontal bacteria, might be considered potential risk factors for nonalcoholic fatty liver disease (NAFLD). Most studies analyzing this association have focused mainly on a specific periodontal bacteria (Porphyromonas gingivalis) and have involved relatively small study populations (tens or hundreds of individuals). To address this gap, a sizable, nationally representative adult population was utilized to investigate the association between the incidence of NAFLD and high serum IgG antibodies for 19 periodontal bacteria. Methods: To explore this association, data from the Third National Health and Nutrition Examination Survey (NHANES III)—which provides a cross-sectional representation of the noninstitutionalized U.S. population, encompassing 33,994 individuals—were analyzed. Participants aged 40 years and above with data on NAFLD—determined by the gold standard of ultrasound examination (USON)—as well as comprehensive records of serum IgG antibodies against periodontal bacteria, were included, resulting in a final analysis subset of 6,330 individuals. Results: Using a cluster analysis based on the Socransky classification scheme for oral microorganisms, antibody titers for the 19 bacteria were grouped into four clusters—Red-Green, Orange-Blue, Yellow-Orange, and Orange-Red. When these clusters, as well as individual antibody relationships with NAFLD, were examined, the adjusted odds ratios (ORs) ranged from 0.958 [95% confidence interval (CI): 0.916, 1.003] to 1.021 [95% CI: 0.987, 1.055]. This indicated that no statistically significant associations were found (P > 0.05), underscoring the absence of a meaningful link. Conclusions: In summary, it was discovered that there is currently no evidence to correlate serum antibodies to periodontal pathogens with NAFLD in the nationally representative NHANES III. Clinical trial number: Not applicable. [ABSTRACT FROM AUTHOR]

Abstract Background Alterations in the bacteria, such as the periodontal bacteria, might be considered potential risk factors for nonalcoholic fatty liver disease (NAFLD). Most studies analyzing this association have focused mainly on a specific periodontal bacteria (Porphyromonas gingivalis) and have involved relatively small study populations (tens or hundreds of individuals). To address this gap, a sizable, nationally representative adult population was utilized to investigate the association between the incidence of NAFLD and high serum IgG antibodies for 19 periodontal bacteria. Methods To explore this association, data from the Third National Health and Nutrition Examination Survey (NHANES III)—which provides a cross-sectional representation of the noninstitutionalized U.S. population, encompassing 33,994 individuals—were analyzed. Participants aged 40 years and above with data on NAFLD—determined by the gold standard of ultrasound examination (USON)—as well as comprehensive records of serum IgG antibodies against periodontal bacteria, were included, resulting in a final analysis subset of 6,330 individuals. Results Using a cluster analysis based on the Socransky classification scheme for oral microorganisms, antibody titers for the 19 bacteria were grouped into four clusters—Red-Green, Orange-Blue, Yellow-Orange, and Orange-Red. When these clusters, as well as individual antibody relationships with NAFLD, were examined, the adjusted odds ratios (ORs) ranged from 0.958 [95% confidence interval (CI): 0.916, 1.003] to 1.021 [95% CI: 0.987, 1.055]. This indicated that no statistically significant associations were found (P > 0.05), underscoring the absence of a meaningful link. Conclusions In summary, it was discovered that there is currently no evidence to correlate serum antibodies to periodontal pathogens with NAFLD in the nationally representative NHANES III. Clinical trial number Not applicable.

Neutralizing antibodies (NAbs) are considered the primary mechanism of vaccine‐mediated protection against human papillomaviruses (HPV), the causative agent of cervical cancer. However, the minimum level of NAb needed for protection is currently unknown. The HPV pseudovirion‐based neutralization assay (PBNA) is the gold standard method for assessing HPV antibody responses but is time‐consuming and labor‐intensive. With the development of higher valency HPV vaccines, alternative serological assays with the capacity for multiplexing would improve efficiency and output. Here we describe a multiplex bead‐based immunoassay to characterize the antibody responses to the seven oncogenic HPV types (HPV16/18/31/33/45/52/58) contained in the current licensed nonavalent HPV vaccine. This assay can measure antibody isotypes and subclasses (total IgG, IgM, IgA1–2, IgG1–4), and can be adapted to measure other antibody features (e.g., Fc receptors) that contribute to vaccine immunity. When tested with serum samples from unvaccinated and vaccinated individuals, we found high concordance between HPV‐specific IgG using this multiplex assay and NAbs measured with PBNA. Overall, this assay is high‐throughput, sample‐sparing, and time‐saving, providing an alternative to existing assays for the measurement and characterization of HPV antibody responses. [ABSTRACT FROM AUTHOR]

Rabies, a viral disease spread by infected animal bites that causes encephalitis in humans and other mammals, is a neglected infectious disease present on all continents except Antarctica. Spain has been free of terrestrial rabies since 1978. However, due to its geographical situation, it represents a bridge for imported cases from an endemic continent such as Africa to Europe. Rabies vaccination in dogs is an essential preventive tool against this zoonosis. The aim of this study was to determine the state of the immune response against rabies virus in dogs in Spain and to demonstrate whether several factors that have been previously related to the influence of the seroprevalence of this species are involved here. The seroconversion level of this zoonotic virus was assessed in a total of 1060 animals. Indirect ELISA was used to obtain data for statistical analysis to evaluate the studied variables. Working under the concept of One Health, this study provides relevant information to be taken into consideration not only to prevent re-emergence in countries free of this disease but also for prevention and control in endemic countries. [ABSTRACT FROM AUTHOR]

Introduction: The purpose of this study was to investigate whether the inactivated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine has a similar effectiveness and safety profile in patients with rheumatic and musculoskeletal diseases (RMDs) and healthy controls (HCs). Methods: Between August 10, 2021 and September 30, 2021, 134 HCs and 269 patients with RMDs were recruited. All participants who tested negative for COVID-19 were vaccinated with SARS-CoV-2 inactivated vaccine. Next, 150 patients with RMDs and 30 HCs infected with the SARS-CoV-2 Omicron variant within the previous 12 weeks were recruited between February 20, 2023 and March 1, 2023. Serum samples were collected from each participant, and the serum immunoglobulin G (IgG) and immunoglobulin M (IgM) antibody titers against SARS-CoV-2 were determined using a chemiluminescence assay. Results: No statistically significant difference was found in the titer of anti-SARS-CoV-2 IgG and IgM antibodies, or in the incidence of vaccination-related adverse events between the RMD and HC groups (P = 0.183, P = 0.903, and P = 0.27, respectively). Serum IgG titers of SARS-CoV-2 neutralizing antibodies were significantly higher in patients who received two or more doses of inactivated vaccine than in patients who were unvaccinated or had received one dose of vaccine (244.36 ± 109.79 vs. 66.20 ± 82.50; P < 0.001). Conclusions: SARS-CoV-2 inactivated vaccines have similar protective effects in HCs and patients with RMDs, with an appreciable safety profile. Fully vaccinated patients with RMDs infected with the Omicron variant were able to produce effective neutralizing antibody concentrations. [ABSTRACT FROM AUTHOR]

Abstract Introduction The purpose of this study was to investigate whether the inactivated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine has a similar effectiveness and safety profile in patients with rheumatic and musculoskeletal diseases (RMDs) and healthy controls (HCs). Methods Between August 10, 2021 and September 30, 2021, 134 HCs and 269 patients with RMDs were recruited. All participants who tested negative for COVID-19 were vaccinated with SARS-CoV-2 inactivated vaccine. Next, 150 patients with RMDs and 30 HCs infected with the SARS-CoV-2 Omicron variant within the previous 12 weeks were recruited between February 20, 2023 and March 1, 2023. Serum samples were collected from each participant, and the serum immunoglobulin G (IgG) and immunoglobulin M (IgM) antibody titers against SARS-CoV-2 were determined using a chemiluminescence assay. Results No statistically significant difference was found in the titer of anti-SARS-CoV-2 IgG and IgM antibodies, or in the incidence of vaccination-related adverse events between the RMD and HC groups (P = 0.183, P = 0.903, and P = 0.27, respectively). Serum IgG titers of SARS-CoV-2 neutralizing antibodies were significantly higher in patients who received two or more doses of inactivated vaccine than in patients who were unvaccinated or had received one dose of vaccine (244.36 ± 109.79 vs. 66.20 ± 82.50; P

Abstract The available differentiating tests for Chlamydia are based on detection of genetic material and only give information about the actual infection status, but reveal nothing of past infections. As the use of serological methods increases the window of detection, the goal of this study was to investigate if it is possible to develop a differentiating serological test for antibodies against Chlamydia species in chicken sera. Focus was on C. psittaci, C. gallinacea, and two closely related species, i.e. C. abortus and C. avium. To enable differentiating serology, a bead-based Luminex suspension array was constructed, using peptides as antigens, derived from known immunoreactive Chlamydia proteins. For the majority of these peptides, species-specific seroreactivity in mammalian sera has been reported in literature. The suspension array correctly identified antibodies against various Chlamydia species in sera from experimentally infected mice, and was also able to differentiate between antibodies against C. psittaci and C. gallinacea in sera from experimentally infected chickens. In field sera, signals were difficult to interpret as insufficient sera from experimentally infected chickens were available for evaluating the seroreactivity of all peptides. Nevertheless, results of the suspension array with field sera are supported by published data on the occurrence of C. gallinacea in Dutch layers, thereby demonstrating the proof of concept of multiplex serology for Chlamydial species in poultry.

Rabies, a viral disease spread by infected animal bites that causes encephalitis in humans and other mammals, is a neglected infectious disease present on all continents except Antarctica. Spain has been free of terrestrial rabies since 1978. However, due to its geographical situation, it represents a bridge for imported cases from an endemic continent such as Africa to Europe. Rabies vaccination in dogs is an essential preventive tool against this zoonosis. The aim of this study was to determine the state of the immune response against rabies virus in dogs in Spain and to demonstrate whether several factors that have been previously related to the influence of the seroprevalence of this species are involved here. The seroconversion level of this zoonotic virus was assessed in a total of 1060 animals. Indirect ELISA was used to obtain data for statistical analysis to evaluate the studied variables. Working under the concept of One Health, this study provides relevant information to be taken into consideration not only to prevent re-emergence in countries free of this disease but also for prevention and control in endemic countries.

The available differentiating tests for Chlamydia are based on detection of genetic material and only give information about the actual infection status, but reveal nothing of past infections. As the use of serological methods increases the window of detection, the goal of this study was to investigate if it is possible to develop a differentiating serological test for antibodies against Chlamydia species in chicken sera. Focus was on C. psittaci, C. gallinacea, and two closely related species, i.e. C. abortus and C. avium. To enable differentiating serology, a bead-based Luminex suspension array was constructed, using peptides as antigens, derived from known immunoreactive Chlamydia proteins. For the majority of these peptides, species-specific seroreactivity in mammalian sera has been reported in literature. The suspension array correctly identified antibodies against various Chlamydia species in sera from experimentally infected mice, and was also able to differentiate between antibodies against C. psittaci and C. gallinacea in sera from experimentally infected chickens. In field sera, signals were difficult to interpret as insufficient sera from experimentally infected chickens were available for evaluating the seroreactivity of all peptides. Nevertheless, results of the suspension array with field sera are supported by published data on the occurrence of C. gallinacea in Dutch layers, thereby demonstrating the proof of concept of multiplex serology for Chlamydial species in poultry. [ABSTRACT FROM AUTHOR]

Extensively drug-resistant Acinetobacter baumannii is considered one of the most dangerous threats to global health, requiring novel therapeutic interventions. The outer membrane protein A (OmpA) is an immunogenic agent that triggers immune responses. The current study evaluated serum antibody levels against previously determined immunogenic OmpA peptides from A baumannii in ICU staff. Serum samples were collected from 62 ICU staff members (representing the exposed group), healthy controls (representing the nonexposed group), and patients with systemic lupus erythematosus (SLE) (as controls for nonspecific antibody reactions). After excluding the cross-reactive antibodies via Escherichia coli lysate pretreatment, all the samples were assessed in the vicinity of A baumannii lysate by enzyme-linked immunosorbent assay (ELISA). All the positive samples were assessed for interaction with previously designed and selected peptides using ELISA. The protective potential of positive serum antibodies was surveyed in vitro using an opsonophagocytic study. The most antibody positive samples against one of the dominant peptides were determined in the ICU personnel (75%). SLE serum samples did not react with candidate peptides. The strongest positive reaction was observed in serum treatment with one of the OmpA peptides (No. 5) with significant differences compared to other designed peptides. Our findings showed that ICU samples have substantially higher antibody levels than the nonexposed group; Positive samples show strong results in the opsonophagocytosiis assay. This study demonstrates A baumannii colonization at human mucosal surfaces, especially in exposed healthy workers. Novel OmpA-derived peptides could be used to identify immunogenic vaccine candidates. Therefore, more studies are needed before this peptide and antibody levels are used in diagnosis, prevention, or treatment. [ABSTRACT FROM AUTHOR]

In this retrospective cohort study, we investigated the formation of individual classes of antibodies to SARS-CoV-2 in archived serial sera from hospitalized patients with the medium–severe (n = 17) and severe COVID-19 (n = 11). The serum/plasma samples were studied for the presence of IgG, IgM and IgA antibodies to the recombinant S- and N-proteins of SARS-CoV-2. By the 7th day of hospitalization, an IgG increase was observed in patients both with a positive PCR test and without PCR confirmation of SARS-CoV-2 infection. Significant increases in the anti-spike IgG levels were noted only in moderate COVID-19. The four-fold increase of IgM to N-protein was obtained more often in the groups with mild and moderate infections. The IgA levels decreased during the infection to both the S- and N-proteins, and the most pronounced decrease was in the severe COVID-19 patients. The serum IgG to S-protein one week after hospitalization demonstrated a high-power relationship (rs = 0.75) with the level of RBD antibodies. There was a medium strength relationship between the levels of CRP and IgG (rs = 0.43). Thus, in patients with acute COVID-19, an increase in antibodies can develop as early as 1 week of hospital stay. The SARS-CoV-2 antibody conversions may confirm SARS-CoV-2 infection in PCR-negative patients. [ABSTRACT FROM AUTHOR]

Background: Monitoring antibody response following SARS-CoV-2 vaccination is strategic, and neutralizing antibodies represent the gold standard. The neutralizing response to Beta and Omicron VOCs was evaluated versus the gold standard by a new commercial automated assay. Methods: Serum samples from 100 healthcare workers from the Fondazione Policlinico Universitario Campus Biomedico and the Pescara Hospital were collected. IgG levels were determined by chemiluminescent immunoassay (Abbott Laboratories, Wiesbaden, Germany) and serum neutralization assay as the gold standard. Moreover, a new commercial immunoassay, the PETIA test Nab (SGM, Rome, Italy), was used for neutralization evaluation. Statistical analysis was performed with R software, version 3.6.0. Results: Anti-SARS-CoV-2 IgG titers decayed during the first ninety days after the vaccine second dose. The following booster dose significantly (p < 0.001) increased IgG levels. A correlation between IgG expression and neutralizing activity modulation was found with a significant increase after the second and the third booster dose (p < 0.05. Compared to the Beta variant of the virus, the Omicron VOC was associated with a significantly larger quantity of IgG antibodies needed to achieve the same degree of neutralization. The best Nab test cutoff for high neutralization titer (≥1:80) was set for both Beta and Omicron variants. Conclusion: This study correlates vaccine-induced IgG expression and neutralizing activity using a new PETIA assay, suggesting its usefulness for SARS-CoV2 infection management. [ABSTRACT FROM AUTHOR]

Extensively drug-resistant Acinetobacter baumannii is considered one of the most dangerous threats to global health, requiring novel therapeutic interventions. The outer membrane protein A (OmpA) is an immunogenic agent that triggers immune responses. The current study evaluated serum antibody levels against previously determined immunogenic OmpA peptides from A baumannii in ICU staff. Serum samples were collected from 62 ICU staff members (representing the exposed group), healthy controls (representing the nonexposed group), and patients with systemic lupus erythematosus (SLE) (as controls for nonspecific antibody reactions). After excluding the cross-reactive antibodies via Escherichia coli lysate pretreatment, all the samples were assessed in the vicinity of A baumannii lysate by enzyme-linked immunosorbent assay (ELISA). All the positive samples were assessed for interaction with previously designed and selected peptides using ELISA. The protective potential of positive serum antibodies was surveyed in vitro using an opsonophagocytic study. The most antibody positive samples against one of the dominant peptides were determined in the ICU personnel (75%). SLE serum samples did not react with candidate peptides. The strongest positive reaction was observed in serum treatment with one of the OmpA peptides (No. 5) with significant differences compared to other designed peptides. Our findings showed that ICU samples have substantially higher antibody levels than the nonexposed group; Positive samples show strong results in the opsonophagocytosiis assay. This study demonstrates A baumannii colonization at human mucosal surfaces, especially in exposed healthy workers. Novel OmpA-derived peptides could be used to identify immunogenic vaccine candidates. Therefore, more studies are needed before this peptide and antibody levels are used in diagnosis, prevention, or treatment.

Summary: Background: The higher hospitalisation rates of those aged 0–19 years (referred to herein as ‘children’) observed since the emergence of the immune-evasive SARS-CoV-2 Omicron variant and subvariants, along with the persisting vaccination disparities highlighted a need for in-depth knowledge of SARS-CoV-2 sero-epidemiology in children. Here, we conducted this systematic review to assess SARS-CoV-2 seroprevalence and determinants in children worldwide. Methods: In this systematic review and meta-analysis study, we searched international and preprinted scientific databases from December 1, 2019 to July 10, 2022. Pooled seroprevalences were estimated according to World Health Organization (WHO) regions (at 95% confidence intervals, CIs) using random-effects meta-analyses. Associations with SARS-CoV-2 seroprevalence and sources of heterogeneity were investigated using sub-group and meta-regression analyses. The protocol used in this study has been registered in PROSPERO (CRD42022350833). Findings: We included 247 studies involving 757,075 children from 70 countries. Seroprevalence estimates varied from 7.3% (5.8–9.1%) in the first wave of the COVID-19 pandemic to 37.6% (18.1–59.4%) in the fifth wave and 56.6% (52.8–60.5%) in the sixth wave. The highest seroprevalences in different pandemic waves were estimated for South-East Asia (17.9–81.8%) and African (17.2–66.1%) regions; while the lowest seroprevalence was estimated for the Western Pacific region (0.01–1.01%). Seroprevalence estimates were higher in children at older ages, in those living in underprivileged countries or regions, and in those of minority ethnic backgrounds. Interpretation: Our findings indicate that, by the end of 2021 and before the Omicron wave, around 50–70% of children globally were still susceptible to SARS-CoV-2 infection, clearly emphasising the need for more effective vaccines and better vaccination coverage among children and adolescents, particularly in developing countries and minority ethnic groups. Funding: None.

Human influenza virus evolves to escape neutralization by polyclonal antibodies. However, we have a limited understanding of how the antigenic effects of viral mutations vary across the human population and how this heterogeneity affects virus evolution. Here, we use deep mutational scanning to map how mutations to the hemagglutinin (HA) proteins of two H3N2 strains, A/Hong Kong/45/2019 and A/Perth/16/2009, affect neutralization by serum from individuals of a variety of ages. The effects of HA mutations on serum neutralization differ across age groups in ways that can be partially rationalized in terms of exposure histories. Mutations that were fixed in influenza variants after 2020 cause greater escape from sera from younger individuals compared with adults. Overall, these results demonstrate that influenza faces distinct antigenic selection regimes from different age groups and suggest approaches to understand how this heterogeneous selection shapes viral evolution. [Display omitted] • Measure how mutations to influenza hemagglutinin affect neutralization by human sera • Compare antigenic effects of mutations on sera from individuals of different ages • Evolution of virus appears to be especially driven by sera from teenagers Welsh et al. measured how mutations to H3N2 influenza hemagglutinin affected neutralization by sera from individuals of different age groups. The mutations that affected neutralization varied among age groups. During its natural evolution, the H3N2 influenza virus especially acquires mutations that escape neutralization by sera from teenagers. [ABSTRACT FROM AUTHOR]

MBCs (MBCs) generated in T-dependent immune responses can persist for a lifetime and rapidly react upon secondary antigen exposure to differentiate into plasma cells (PCs) and/or to improve the affinity of their BCR through new rounds of hypermutation in germinal centers (GCs). The fate of a MBC in secondary immune reactions appears to depend upon multiple parameters, whose understanding is mandatory for the design of efficient vaccine strategies. We followed the behavior of MBCs in recall responses to SRBCs using an inducible AID fate mapping mouse model in which B cells engaged in a germinal center (GC) response are irreversibly labeled upon simultaneous tamoxifen ingestion and immunization. We used different schemes of mouse immunization and tamoxifen feeding in adoptive-transfer experiments of total splenic B cells into congenic mice that have been pre-immunized or not, to assess the contribution of the different effector subsets in a physiological competitive context. We were able to show that naive B cells can differentiate into GC B cells with kinetics similar to MBCs in the presence of previously activated T follicular helper (TFH) cells and a primed microenvironment. We also showed that MBCs are recruited into secondary GCs, together with naive B cells. In contrast, PC differentiation, which dominated secondary MBC responses, was not dependent upon a previous TFH activation. We observed that the presence of persisting germinal centers and circulating antibody levels are key factors determining the germinal center versus plasma cell fate in a recall response. Notably, disruption of persistent germinal center structures by a lymphotoxin beta-receptor fusion protein or a longer timing between the prime and the boost, which correlated with reduced antigen-specific immunoglobulin levels in serum, were two conditions with an opposite impact, respectively inhibiting or promoting a GC fate for MBCs. Altogether, these studies highlight the complexity of recall responses, whose outcome varies according to immunization contexts. [ABSTRACT FROM AUTHOR]

Whether people living with HIV (PLWH) are at greater risk of acquiring SARS‐CoV‐2 infection is currently unknown. Prospective serologic studies may allow seroincidence analyses, where all infections are accurately identified. Because of this, we evaluated the incidence of associated factors with and the clinical outcome of SARS‐CoV‐2 infection in PLWH in Southern Spain. This prospective cohort study included PLWH from a Tertiary University Hospital in Southern Spain. Patients were enrolled in the study if (1) they had attended as outpatients our Unit from 1 August 2019 to 8 February 2020 and (2) had two subsequent evaluations from 9 February 2020 to 4 March 2021. SARS‐CoV‐2 infections were diagnosed by PCR, antigen detection or serology. Seven hundred and nine PLWH were included in the study. Of them, 55 [7.8%, 95% confidence interval (95% CI) 5.9%–9.9%] patients developed SARS‐CoV‐2 infection. Between 18 May and 29 November 2020, the rate of seroconversion was 5.3% (95% CI: 3.1%–9.0%) for the general population in the area of Seville and 2.3% (95% CI: 1.3%–2.6%) for PLWH in this study (p =.001). After multivariable analysis, adjusted by age, sex, and risk factors for HIV infection, active tobacco use and CDC stage, active tobacco smoking was the only factor independently associated with lower risk of SARS‐Cov‐2 infection [Incidence rate ratio: 0.29 (95% CI 0.16–0.55) p <.001]. In conclusion, the incidence of SARS‐CoV‐2 infection among PLWH in Southern Spain during the ongoing pandemic was lower than that reported for the general population in the same area. [ABSTRACT FROM AUTHOR]

MBCs (MBCs) generated in T-dependent immune responses can persist for a lifetime and rapidly react upon secondary antigen exposure to differentiate into plasma cells (PCs) and/or to improve the affinity of their BCR through new rounds of hypermutation in germinal centers (GCs). The fate of a MBC in secondary immune reactions appears to depend upon multiple parameters, whose understanding is mandatory for the design of efficient vaccine strategies. We followed the behavior of MBCs in recall responses to SRBCs using an inducible AID fate mapping mouse model in which B cells engaged in a germinal center (GC) response are irreversibly labeled upon simultaneous tamoxifen ingestion and immunization. We used different schemes of mouse immunization and tamoxifen feeding in adoptive-transfer experiments of total splenic B cells into congenic mice that have been pre-immunized or not, to assess the contribution of the different effector subsets in a physiological competitive context. We were able to show that naive B cells can differentiate into GC B cells with kinetics similar to MBCs in the presence of previously activated T follicular helper (TFH) cells and a primed microenvironment. We also showed that MBCs are recruited into secondary GCs, together with naive B cells. In contrast, PC differentiation, which dominated secondary MBC responses, was not dependent upon a previous TFH activation. We observed that the presence of persisting germinal centers and circulating antibody levels are key factors determining the germinal center versus plasma cell fate in a recall response. Notably, disruption of persistent germinal center structures by a lymphotoxin beta-receptor fusion protein or a longer timing between the prime and the boost, which correlated with reduced antigen-specific immunoglobulin levels in serum, were two conditions with an opposite impact, respectively inhibiting or promoting a GC fate for MBCs. Altogether, these studies highlight the complexity of recall responses, whose outcome varies according to immunization contexts.

Objectives: We explored the effect of antiretroviral treatment (ART) history on clinical characteristics of patients with SARS-CoV-2 and HIV co-infection. Methods: We retrospectively reviewed 20 patients with laboratory-confirmed co-infection of SARS-CoV-2 and HIV in a designated hospital. Patients were divided into medicine (n = 12) and non-medicine (n = 8) groups according to previous ART history before SARS-CoV-2 infection. Results: The median age was 46.5 years and 15 (75%) were female. Ten patients had initial negative RT-PCR on admission, five of which had normal computed tomography (CT) appearance and four were asymptomatic. Lymphocytes were low in nine patients (45%); CD4 cell count and CD4/CD8 were low in all patients. The predominant CT features in 19 patients were multiple (42%) ground-glass opacities (58%) and consolidations (32%). Erythrocyte sedimentation rate was significantly lower in the medicine than the non-medicine group [median (interquartile range, IQR): 14.0 (10.0–34.0) vs 51.0 (35.8–62.0), P = 0.005]. Nineteen patients (95%) were discharged with a median hospital stay of 30 days (IQR 26–30). Conclusions: Most patients with SARS-CoV-2 and HIV co-infection exhibited mild to moderate symptoms. The milder inflammatory response to SARS-CoV-2 infection might be associated with a previous history of ART in HIV-infected patients.

Background: Monitoring antibody response following SARS-CoV-2 vaccination is strategic, and neutralizing antibodies represent the gold standard. The neutralizing response to Beta and Omicron VOCs was evaluated versus the gold standard by a new commercial automated assay. Methods: Serum samples from 100 healthcare workers from the Fondazione Policlinico Universitario Campus Biomedico and the Pescara Hospital were collected. IgG levels were determined by chemiluminescent immunoassay (Abbott Laboratories, Wiesbaden, Germany) and serum neutralization assay as the gold standard. Moreover, a new commercial immunoassay, the PETIA test Nab (SGM, Rome, Italy), was used for neutralization evaluation. Statistical analysis was performed with R software, version 3.6.0. Results: Anti-SARS-CoV-2 IgG titers decayed during the first ninety days after the vaccine second dose. The following booster dose significantly (p < 0.001) increased IgG levels. A correlation between IgG expression and neutralizing activity modulation was found with a significant increase after the second and the third booster dose (p < 0.05. Compared to the Beta variant of the virus, the Omicron VOC was associated with a significantly larger quantity of IgG antibodies needed to achieve the same degree of neutralization. The best Nab test cutoff for high neutralization titer (≥1:80) was set for both Beta and Omicron variants. Conclusion: This study correlates vaccine-induced IgG expression and neutralizing activity using a new PETIA assay, suggesting its usefulness for SARS-CoV2 infection management.

In this retrospective cohort study, we investigated the formation of individual classes of antibodies to SARS-CoV-2 in archived serial sera from hospitalized patients with the medium–severe (n = 17) and severe COVID-19 (n = 11). The serum/plasma samples were studied for the presence of IgG, IgM and IgA antibodies to the recombinant S- and N-proteins of SARS-CoV-2. By the 7th day of hospitalization, an IgG increase was observed in patients both with a positive PCR test and without PCR confirmation of SARS-CoV-2 infection. Significant increases in the anti-spike IgG levels were noted only in moderate COVID-19. The four-fold increase of IgM to N-protein was obtained more often in the groups with mild and moderate infections. The IgA levels decreased during the infection to both the S- and N-proteins, and the most pronounced decrease was in the severe COVID-19 patients. The serum IgG to S-protein one week after hospitalization demonstrated a high-power relationship (rs = 0.75) with the level of RBD antibodies. There was a medium strength relationship between the levels of CRP and IgG (rs = 0.43). Thus, in patients with acute COVID-19, an increase in antibodies can develop as early as 1 week of hospital stay. The SARS-CoV-2 antibody conversions may confirm SARS-CoV-2 infection in PCR-negative patients.

Experimental studies demonstrated antibodies against matrix and coating of polyester‐based vascular prostheses. Thus, this study examined associations of these antibodies with serum cytokines (IL‐2, IL‐4, and IL‐10) and local inflammatory reactions. Rats (n = 8/group) intramuscularly received prosthesis segments [PET‐C, PET‐G, and PET‐A groups: polyethylene terephthalate (PET)‐based prostheses coated with bovine collagen and gelatin or human serum albumin, respectively; uncoated polytetrafluoroethylene‐based (PTFE) prosthesis], with sham‐operated controls. Blood was drawn pre‐operatively and weekly until day 22. Polymer‐specific or coating‐specific antibodies and cytokines were detected by enzyme immunoassays, inflammatory reactions were immunohistochemically evaluated on day 23. Polymer‐specific antibodies were detected in all PET‐groups using uncoated PET as antigenic target, but not for PTFE or controls, coating‐specific antibodies only for PET‐A. IL‐10 was increased in all PET‐groups and correlated with polymer‐specific antibodies for PET‐G and PET‐A. IL‐2 was increased for PET‐A, but overall correlated with PET‐specific antibodies. IL‐4 remained unchanged in all groups. Intense local inflammatory reactions (ED1+/ED2+ macrophages and T lymphocytes) were found within all PET‐groups, but only minor for PTFE or controls. In conclusion, PET‐specific antibodies were associated with increased IL‐10 and along with concurrent coating‐specific antibodies also with increased IL‐2, indicating a specific T cell response. Thus, matrix and/or coating of polymeric vascular prostheses elicit distinct systemic immune reactions, probably influencing local inflammatory reactions. [ABSTRACT FROM AUTHOR]

With limited vaccine supplies, an informed position on the status of SARS-CoV-2 infection in people can assist the prioritization of vaccine deployment. We performed a systematic review and meta-analysis to estimate the global and regional SARS-CoV-2 seroprevalences around the world. We systematically searched peer-reviewed databases (PubMed, Embase and Scopus), and preprint servers (medRxiv, bioRxiv and SSRN) for articles published between 1 January 2020 and 30 March 2021. Population-based studies reporting the SARS-CoV-2 seroprevalence in the general population were included. People of different age groups, occupations, educational levels, ethnic backgrounds and socio-economic status from the general population. There were no interventions. We used the random-effects meta-analyses and empirical Bayesian method to estimate the pooled seroprevalence and conducted subgroup and meta-regression analyses to explore potential sources of heterogeneity as well as the relationship between seroprevalence and socio-demographics. We identified 241 eligible studies involving 6.3 million individuals from 60 countries. The global pooled seroprevalence was 9.47% (95% CI 8.99–9.95%), although the heterogeneity among studies was significant (I 2 = 99.9%). We estimated that ∼738 million people had been infected with SARS-CoV-2 (as of December 2020). Highest and lowest seroprevalences were recorded in Central and Southern Asia (22.91%, 19.11–26.72%) and Eastern and South-eastern Asia (1.62%, 1.31–1.95%), respectively. Seroprevalence estimates were higher in males, persons aged 20–50 years, in minority ethnic groups living in countries or regions with low income and human development indices. The present study indicates that the majority of the world's human population was still highly susceptible to SARS-CoV-2 infection in mid-2021, emphasizing the need for vaccine deployment to vulnerable groups of people, particularly in developing countries, and for the implementation of enhanced preventive measures until 'herd immunity' to SARS-CoV-2 has developed. [ABSTRACT FROM AUTHOR]

Abstract Background Serum antibody detection has potential as a complementary diagnostic tool in animal tuberculosis (TB) control, particularly in multi-host systems. The objective of the present study was to assess the specificity (Sp) of an enzyme-linked immunosorbent assay (ELISA) based on the new multiprotein complex P22 for the detection of specific antibodies against the Mycobacterium tuberculosis complex (MTC) in the four most relevant domestic animals acting as MTC hosts: cattle, goat, sheep and pig. We used sera from an officially TB-free (OTF) country, Norway, and from a non-OTF one, Spain. The samples included sera from goats that had been vaccinated against M. avium subsp. paratuberculosis (MAP) and sheep from a herd in which Corynebacterium pseudotuberculosis had been isolated. Results In cattle, the Sp ranged from 92.5 (IC95% 90.7–94) to 99.4% (IC95% 98.3–99.8) depending on the cut-off used and the origin of the samples (Spain or Norway). Sp in cattle (cut-off point 100) was significantly higher (P

The ongoing SARS-CoV-2 pandemic infecting millions of people globally has given rise to serious public health threats. The need for early detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in asymptomatic pregnant women is compelling to detect vertical transmission timely. Here, 11 SARS-CoV-2 asymptomatic pregnant cases from Wuhan China were investigated. All the patients were initially tested negative for SARS-CoV-2 on RT-PCR, so a chest CT scan was performed. Also, serum antibody (IgM and IgG) titers were estimated. CT scan of patients revealed typical abnormalities related to SARS-CoV-2, indicating ground-glass opacity and infection lesions suggesting viral pneumonia. Elevated IgM and IgG antibodies levels (p

Objective. To determine the prevalence of antibodies against Neospora caninum (PSA) in beef and dual-purpose cattle from the Central and Southern Gulf of Mexico regions, as well as to evaluate its association with the reproductive status (RS) of the cow (pregnant, not pregnant). Materials and methods. Blood samples were taken from 422 cows. Antibodies were detected with a commercial ELISA kit. PSA was analyzed with a logistic regression model that included state, township nested within state, and ranch nested within township. Results. The states of Tabasco, Puebla and Veracruz had similar PSA (p>0.05). The mean PSA for the three states was 24.0%. The PSA varied from 7.8 to 43.3% across townships. In Puebla, the PSA in cattle from San José Acateno township was more than two-fold greater than that in cattle from Hueytamalco and Nauzontla townships (p0.05) PSA. In Veracruz, cows from Cotaxtla and Medellín de Bravo townships presented higher (p0.05) to that of seronegative females. Conclusions. The three states had similar PSA. All the herds had antibodies against N. caninum, suggesting that this parasite is amply distributed in the three states. In addition, great variation existed among herds and among townships; finally, the presence of N. caninum antibodies was not associated with the RS of the cow.

Background and Aim: Leishmania spp. are known to cause disease in man and animals. Rats are considered important reservoir hosts and transmission takes place through the bite of female sand fly, Phlebotomus spp. To the best of our knowledge, there is no published information on Leishmania infection in rats in Grenada. This study was conducted to estimate the antibodies for visceralizing Leishmania spp. (VL) in rats (Rattus norvegicus) from Grenada. Materials and Methods: A total of 146 brown rats (R. norvegicus) were trapped live from two parishes (St. George and St. David) in Grenada. Following anesthesia, blood was collected from the heart through thoracic puncture. The serum was collected after the centrifugation of blood. Serum was tested for antibodies to VL. with a commercially available immunochromatographic dipstick test which is licensed for use in animals and humans. Results: The seroprevalence of antibodies against Leishmania spp. was found in 34 of 146 rats (23.3%; CI 95% from 16.70 to 30.99). No significant differences were found between sexes and young or adults. The prevalence between parishes (St. George and St. David) was also not significant. Conclusion: The results show that rats (R. norvegicus) in Grenada are exposed to Leishmania spp. The rats could play an important role in the transmission of leishmaniasis to humans and other animals in Grenada.

Objective. To determine the prevalence of antibodies against Neospora caninum (PSA) in beef and dual-purpose cattle from the Central and Southern Gulf of Mexico regions, as well as to evaluate its association with the reproductive status (RS) of the cow (pregnant, not pregnant). Materials and methods. Blood samples were taken from 422 cows. Antibodies were detected with a commercial ELISA kit. PSA was analyzed with a logistic regression model that included state, township nested within state, and ranch nested within township. Results. The states of Tabasco, Puebla and Veracruz had similar PSA (p>0.05). The mean PSA for the three states was 24.0%. The PSA varied from 7.8 to 43.3% across townships. In Puebla, the PSA in cattle from San José Acateno township was more than two-fold greater than that in cattle from Hueytamalco and Nauzontla townships (p<0.05). In Tabasco, Cunduacán, Huimanguillo and Ranchería El Puente townships showed similar (p>0.05) PSA. In Veracruz, cows from Cotaxtla and Medellín de Bravo townships presented higher (p<0.05) PSA than those from San Rafael township. The RS of seropositive females was similar (p>0.05) to that of seronegative females. Conclusions. The three states had similar PSA. All the herds had antibodies against N. caninum, suggesting that this parasite is amply distributed in the three states. In addition, great variation existed among herds and among townships; finally, the presence of N. caninum antibodies was not associated with the RS of the cow. [ABSTRACT FROM AUTHOR]

Backyard chickens in rural communities of developing countries provide a potential means for the production of resilient, integrated small poultry farming systems. Despite this, they are often affiliated with the transmission of the economically important Newcastle disease virus (NDV). Presently, in Trinidad, information gaps exist regarding the backyard chicken population. To promote a better understanding of the serological status to NDV in this farming system, 303 unvaccinated backyard chickens from 11 farms across five counties in Trinidad were assessed for the presence of serum NDV antibodies using two commercial enzyme-linked immunosorbent assays (ELISAs). The study also explored the potential application of egg yolk samples for serological testing using a chloroform-free technique. In addition, data on farm locations, demographics, vaccination status, general management and biosecurity practices were obtained using a cross-sectional survey. An association was identified between the ID Screen® Newcastle Disease Conventional Vaccines (NDVS-CV) ELISA and the ID Screen® Newcastle Disease Nucleoprotein Indirect (NDVNP) ELISA (X2 1df, P = 0.001). The results indicate the presence of two different NDV antibody types in the serum of unvaccinated backyard chickens across farms in Trinidad. Differences in test seropositivity are suggestive of the influence of geospatial, general management, biosecurity and husbandry factors. These results can provide a useful background in the design of prospective NDV studies that aim at bridging the knowledge gap to promote situational awareness. [ABSTRACT FROM AUTHOR]

• Compared with SARS-CoV-2 infected general population, patients with HIV co-infection mostly have milder clinical presentation. • A single test of viral RNA test and antibodies against SARS-CoV-2 might be insufficient to exclude COVID-19 infection in patients with HIV. • The milder extent of inflammatory response to SARS-CoV-2 infection might be associated with a previous history of ART in HIV-infected patients. We aimed to explore the effect of antiretroviral treatment (ART) history on clinical characteristics of patients with co-infection of SARS-CoV-2 and HIV. We retrospectively reviewed 20 patients with laboratory-confirmed co-infection of SARS-CoV-2 and HIV in a designated hospital. Patients were divided into medicine group (n = 12) and non-medicine group (n = 8) according to previous ART history before SARS-CoV-2 infection. The median age was 46.5 years and 15 (75%) were female. Ten patients had initial negative RT-PCR on admission, 5 of which had normal CT appearance and 4 were asymptomatic. Lymphocytes were low in 9 patients (45%), CD4 cell count and CD4/CD8 were low in all patients. The predominant CT features in 19 patients were multiple (42%) ground-glass opacities (58%) and consolidations (32%). Erythrocyte sedimentation rate (ESR) in the medicine group was significantly lower than that in the non-medicine group [median (interquartile range, IQR):14.0 (10.0–34.0) vs. 51.0 (35.8–62.0), P = 0.005]. Nineteen patients (95%) were discharged with a median hospital stay of 30 days (IQR, 26–30). Most patients with SARS-CoV-2 and HIV co-infection exhibited mild to moderate symptoms. The milder extent of inflammatory response to SARS-CoV-2 infection might be associated with a previous history of ART in HIV-infected patients. [ABSTRACT FROM AUTHOR]

Introduction: Persistent human papillomavirus (HPV) semen infection is increasingly associated with male infertility. Adjuvant HPV vaccination is suggested to reduce the time to clearance and the disease relapse in males with persistent HPV semen infection. However, only a sub-population of patients show a clinical benefit from adjuvant vaccination. Here, we aimed to address the effectiveness rate of HPV adjuvant vaccination in males with genital tract infection and the possible prognostic markers of healing. Methods: Clinical records from 379 patients with persistent seminal HPV detection, all receiving HPV adjuvant vaccination, were considered. Clinical data, including genital HPV-DNA assessment by INNO-LiPA genotyping, semen HPV-DNA analysis by FISH analysis and serum antibody titer, were collected at basal (T0) and after 6 months (T1) since the vaccination cycle ended. Results: Clearance of genital HPV-DNA was recorded in 326 (86%) patients. Serum HPV-antibody titer at T1 was the most important prognostic factor associated with HPV-DNA clearance. A serum antibody titer equal to or greater than the threshold value 1:125, obtained by ROC curve analysis, was prognostic of healing. Conclusions: Anti-HPV antibody represents a suitable marker of adequate immune response to HPV vaccination in patients with genital infection.

Abstract: Background: Workplace exposure to trimellitic anhydride (TMA) can elicit TMA‐specific IgE (sIgE), which may lead to occupational asthma (OA). An occupational immunosurveillance program (OISP) has been implemented to monitor TMA exposure and immunologic outcomes. The purpose of this study was to determine whether TMA‐specific IgG (sIgG) responses can discriminate between TMA‐exposed workers with and without sIgE responses. Methods: Serum TMA‐specific antibody (IgG, IgG4, and IgE) levels were estimated longitudinally (years 2006 to 2014) in TMA‐exposed workers recruited in low, medium, and high exposure areas. sIgG and sIgE titers plotted against exposure duration were compared between workers with (a) sIgG only and (b) with sIgG who developed sIgE. Results: Among 92 TMA‐exposed workers continuously monitored for sIgG and sIgE, 38 developed sIgG; 11 developed a sIgE response 342.38 ± 186.03 days posthire and were removed from exposure. The average detection time of sIgG in removed workers (159 ± 92 days) was significantly shorter than for actively exposed workers with only sIgG (346 ± 187 days). Workers with earlier sIgG responses of higher titer (mean value 42.25 μg/mL) compared to delayed responders with lower sIgG titers (mean value 14.79 μg/mL) more frequently developed sIgE responses. Hierarchical clustering showed the initial magnitude and exposure time required for detectable sIgG production discriminated between workers with only sIgG from workers who subsequently produced sIgE. Conclusions: This study demonstrates the utility of longitudinally monitoring TMA‐specific antibodies in an OISP as exposed workers with early sIgG responses and of higher magnitude are more likely to develop TMA sIgE sensitization. [ABSTRACT FROM AUTHOR]

Background: Because of the current epidemic of human papillomavirus (HPV)-related oropharyngeal cancer (OPC), a screening strategy is urgently needed. The presence of serum antibodies to HPV-16 early (E) antigens is associated with an increased risk for OPC. The purpose of this study was to evaluate the diagnostic accuracy of antibodies to a panel of HPV-16 E antigens in screening for OPC.Methods: This case-control study included 378 patients with OPC, 153 patients with nonoropharyngeal head and neck cancer (non-OPC), and 782 healthy control subjects. The tumor HPV status was determined with p16 immunohistochemistry and HPV in situ hybridization. HPV-16 E antibody levels in serum were identified with an enzyme-linked immunosorbent assay. A trained binary logistic regression model based on the combination of all E antigens was predefined and applied to the data set. The sensitivity and specificity of the assay for distinguishing HPV-related OPC from controls were calculated. Logistic regression analysis was used to calculate odds ratios with 95% confidence intervals for the association of head and neck cancer with the antibody status.Results: Of the 378 patients with OPC, 348 had p16-positive OPC. HPV-16 E antibody levels were significantly higher among patients with p16-positive OPC but not among patients with non-OPC or among controls. Serology showed high sensitivity and specificity for HPV-related OPC (binary classifier: 83% sensitivity and 99% specificity for p16-positive OPC).Conclusions: A trained binary classification algorithm that incorporates information about multiple E antibodies has high sensitivity and specificity and may be advantageous for risk stratification in future screening trials. Cancer 2017;123:4886-94. © 2017 American Cancer Society. [ABSTRACT FROM AUTHOR]

Background While vaccine-induced antibodies are known to confer protection against incident human papillomavirus (HPV) infection, there is inconsistent data regarding the protective effect of naturally acquired anti-HPV antibodies. Objectives To estimate the protective effect of naturally acquired anti-HPV16 serum antibodies against incident anogenital infection with HPV16 in females aged 20–64 years and to assess whether antibodies influence the persistence/clearance of anogenital HPV16 infection. Study design 4432 women attending the organized national cervical cancer screening program in Slovenia were initially enrolled. 2199 and 1848 women had valid HPV DNA results obtained using PCR-based assays and HPV antibody serotyping results obtained using pseudovirion-based serological assay, at baseline and at three-year follow-up, respectively. Results Baseline HPV16 seroprevalence was 2.4-fold higher among HPV16 DNA-positive women (55.7% vs. 23.2%; p < 0.01). Baseline HPV16 DNA-positive/seronegative women frequently acquired anti-HPV16 antibodies during follow-up (OR = 8.2; 95% CI: 3.8–17.8). Baseline anti-HPV16 antibodies persisted at follow-up, irrespective of baseline HPV16 DNA status (OR = 40.6; 95% CI: 30.3–54.5). Baseline HPV16 DNA-negative/seropositive women were less likely to acquire HPV16 infection at follow-up (unadjusted OR = 0.2; 0.1–0.9). However, the age-adjusted association was non-significant (adjusted OR = 0.3; 0.1–1.2). The tendency for protective effect was stronger among women older than 25 years (OR = 0.2; 0.03–1.8). Baseline anti-HPV16 antibodies were not associated with persistence/clearance of HPV16 infection at follow-up (OR = 0.8; 0.3–1.9). Conclusions Naturally acquired anti-HPV16 serum antibodies appeared to protect against anogenital HPV16 infection, but this association was at least partially confounded by age. Baseline anti-HPV16 serum antibodies did not influence persistence/clearance of HPV16 infection at follow-up. [ABSTRACT FROM AUTHOR]

In peripheral neuropathies, such as sensorimotor neuropathies, motor neuron diseases, or the Guillain-Barré syndrome, serum antibodies recognizing saccharide units, portion of oligosaccharides, or oligosaccharide chains, have been found. These antibodies are called anti-glycosphingolipid (GSL) or anti-ganglioside antibodies. However, the information on the aglycone carrying the hydrophilic oligosaccharide remains elusive. The absolute and unique association of GSL to the onset, development and symptomatology of the peripheral neuropathies could be misleading. Here, we report some thoughts on the matter. [ABSTRACT FROM AUTHOR]

Short exposures to infrared heat are generally used to facilitate tail-vein bleeding of experimental mice as an alternative to retro-orbital bleeding for the purpose of obtaining serum samples. Altered temperatures have been shown to influence immune responses in a variable manner. This study evaluates the effects of infrared heat on the immune response. After confirming the efficacy of heat exposure as measured by alterations in body temperatures, the exposed mice were evaluated for antigen-specific antibody responses and allogeneic cytotoxic T lymphocytic (CTL) responses as readouts for humoral and cellular immune responses respectively. Antigen-specific serum antibody titers to lysozyme, bovine serum albumin, ovalbumin, diphtheria toxin and rabbit IgG antigens were analyzed in infrared heat exposed and unexposed control C57BL/6 mice that were immunized with the corresponding antigen. Significant decreases in antigen-specific antibody titers were observed only when heat exposed C57BL/6 mice were immunized with lysozyme or BSA but not with other antigens tested. These alterations were not seen in heat exposed BALB/c mice. Dialyzed serum prepared from such heat exposed C57BL/6 was also found to inhibit CTL generation in vitro and inhibited IL-2 stimulated proliferation of CTLL-2 cells. These studies suggest that the procedure of infrared heat exposure prior to tail vein bleeding may influence some immune parameters although this may not be true for all strains of mice and all antigens.

Summary In autoantibody-mediated diseases such as pemphigus, serum antibodies lead to disease. Genetic analysis of B cells has allowed characterization of antibody repertoires in such diseases but would be complemented by proteomic analysis of serum autoantibodies. Here, we show using proteomic analysis that the serum autoantibody repertoire in pemphigus is much more polyclonal than that found by genetic studies of B cells. In addition, many B cells encode pemphigus autoantibodies that are not secreted into the serum. Heavy chain variable gene usage of serum autoantibodies is not shared among patients, implying targeting of the coded proteins will not be a useful therapeutic strategy. Analysis of autoantibodies in individual patients over several years indicates that many antibody clones persist but the proportion of each changes. These studies indicate a dynamic and diverse autoantibody response not revealed by genetic studies and explain why similar overall autoantibody titers may give variable disease activity. [ABSTRACT FROM AUTHOR]

Background: Japanese encephalitis caused by Japanese encephalitis virus (JEV) is an endemic zoonotic disease of high public health importance in the Asian Pacific region. The aim of this study was to investigate the presence of JEV infection in commensal and field rodents in South China. Materials and Methods: RNA copies of JEV were detected in brain samples of rodents using real-time RT-PCR. Detection of serum against JEV-reactive antibodies was performed using indirect enzyme-linked immunosorbent assay and microneutralization test. Results: In total, 198 rodents were collected from Guangzhou City and Xiamen City between November 2013 and May 2014. JEV RNA was not detected in 188 brain samples. Forty-four in 96 serum samples (45.8%) were positive for JEV-reactive IgG antibodies. The prevalence of neutralizing antibodies to against JEV-reactive in these serum samples was 61.5% (24/39), with titers ranging from 1:10 to 1:56. Conclusion: Rodents are not known to play a role in transmission of JEV in Asia, nor is there an evidence to support a role for rodents in transmission of other related flaviviruses in China. However, in the current study, we detected evidence of JEV-reactive antibodies in large numbers of Rattus norvegicus and Rattus losea Swinhoe. Further studies of rodents as potential hosts of JEV or other related flaviviruses are warranted. [ABSTRACT FROM AUTHOR]

Orally delivered mycobacterial antigens may not sensitize the immunized animals causing a positive tuberculin skin test response. As the first step to address this critical issue, we characterized the response of farmed red deer ( Cervus elaphus ) to orally delivered heat-inactivated Mycobacterium bovis . Thirty-two adult red deer hinds from a farm known to be free of tuberculosis (TB) were randomly assigned to two different treatment groups, immunized ( n = 24) and control ( n = 8). Immunized hinds were dosed orally with 2 ml of PBS containing 6 × 10 6 heat-inactivated M. bovis . The mean skin test response of immunized deer to both avian purified protein derivative (aPPD) and bovine PPD (bPPD) was consistently lower in immunized than in control hinds. One year after immunization, immunized hinds had a significant reduction in the skin test response to aPPD and in the ELISA antibody levels against both aPPD and bPPD (24–36% reduction; P < 0.05). By contrast, no significant change was observed in the skin test response to phytohaemagglutinin, or in the ELISA antibody levels against the M. bovis specific antigen MPB70. The mRNA levels for C3, IFN-γ and IL-1β and serum protein levels for IFN-γ and IL-1β did not vary between immunized and control deer. However, serum C3 protein levels were significantly higher ( P = 0.001) in immunized than in control deer six months after immunization. These results confirm that oral heat-inactivated M. bovis does not sensitize farmed red deer and therefore does not cause false-positive responses in the tuberculin skin test. The absence of sensitization in orally immunized deer opens the possibility of testing the vaccine in deer and possibly other ruminants without the risk of causing false-positive reactions in TB-tests. This study also provided the first evidence that orally-delivered inactivated mycobacterial antigens elicit some kind of immune response in a ruminant. [ABSTRACT FROM AUTHOR]

A serological survey on the prevalence of antibodies to Newcastle disease virus (NDV) was carried out in broilers and layers in Faisalabad and surrounding districts. A total of 803 serum samples were collected form broiler farms, layer farms and slaughter shops. Samples were divided into three age groups for broilers; 0-3 weeks (56 samples), 3-5 weeks (164 samples), 5-7 weeks (92 samples) and also into three age groups for layers; 17-27 weeks (168 samples), 27-37 weeks (219 samples) and 37-47 weeks (104 samples). Haemagglutination Inhibition (HI) test was performed to determine the serum antibodies against NDV. Calculated geometric mean titers for broiler groups of 0-3, 3-5 and 5-7 weeks of age were found to be 11.91, 10.01 and 15.85, respectively. These values for layer groups of 17-27 weeks, 27-37 weeks and 37-47 weeks of age were found to be 134.89, 153.46 and 149.62, respectively. The results showed that the level of protection in vaccinated birds was unsatisfactory in broilers, whereas it was satisfactory in layers.

Seroepidemiologic studies of Pneumocystis pneumonia (PCP) in humans have been limited by inadequate reagents. We have developed an enzyme-linked immunosorbent assay (ELISA) using three overlapping recombinant fragments of the human Pneumocystis major surface glycoprotein (MsgA, MsgB, and MsgC) for analysis of antibody responses in HIV-positive patients and healthy blood donors. HIV-positive patients had significantly higher antibody levels to all Msg fragments. Furthermore, HIV-positive patients who experienced a previous episode of PCP (PCP-positive) had higher level of antibodies to MsgC than patients who never had PCP. A significant association was found between ELISA antibody level and reactivity by Western blot in HIV-positive patients, especially those who were PCP-positive. Thus, this ELISA will be useful in studying serum antibody responses to Pneumocystis in different human populations.

OBJETIVO: Determinar si anticuerpos séricos contra E4, E7 y Ras pueden ser utilizados como marcadores de lesiones tempranas del cérvix uterino asociadas al virus del papiloma humano. MATERIAL Y MÉTODOS: Entre marzo de 1999 y abril de 2000 se realizó un estudio sero-epidemiológico de casos y controles en la clínica de displasias del Hospital General Doctor Gea González, en la Ciudad de México, en 116 muestras de suero para evaluar la presencia de anticuerpos anti-E4, E7 y Ras utilizando un ELISA de captura. Se estimaron razones de momios e intervalos de confianza de 95% RESULTADOS: Anticuerpos anti-E7 se asociaron a mujeres con lesiones NIC III, mientras que anticuerpos anti-E4 y anti-Ras fueron más frecuentes en lesiones NIC I-II. Al evaluar el perfil de anticuerpos que presentaron las mujeres, encontramos que a) anticuerpos contra dos proteínas predicen la existencia de una lesión NIC I-II, y b) la presencia de tres anticuerpos predicen una lesión NIC III. CONCLUSIONES: La detección de anticuerpos séricos contra E4, E7 y Ras en combinación con otras técnicas de diagnóstico, podrían ser de utilidad para detectar oportunamente a mujeres con lesiones tempranas asociadas al Virus del Papiloma Humano y en riesgo de desarrollar cáncer.OBJECTIVE: To evaluate whether serum antibodies anti-E4, E7 and Ras could be used as markers for early cervical lesions associated with HPV (human papillomavirus). MATERIAL AND METHODS: A seroepidemiological case-control study was conducted between March 1999 and April 2000 at the dysplasia clinic of Hospital General Doctor Gea Gonzalez, in Mexico City, to evaluate the presence of antibodies anti-E4, E7, and Ras through a sandwich ELISA. Analysis was done using odds ratios and 95% confidence intervals. RESULTS: Anti-E7 antibodies were associated to women with CIN III lesions, while anti-E4 and Ras antibodies were strongly associated with CIN I-II lesions. The antibody profile of women with different cervical lesion showed that: a) the presence of antibodies against two proteins predicts the presence of CIN I-II lesions, and b) the presence of three antibodies predicts a CIN III lesion. CONCLUSIONS: The presence of serum antibodies against E4, E7 and Ras, together with other diagnostic techniques, could be useful for the timely detection of early uterine cervical lesions associated to HPV in women at risk of developing cancer.

Background: The higher hospitalisation rates of those aged 0-19 years (referred to herein as 'children') observed since the emergence of the immune-evasive SARS-CoV-2 Omicron variant and subvariants, along with the persisting vaccination disparities highlighted a need for in-depth knowledge of SARS-CoV-2 sero-epidemiology in children. Here, we conducted this systematic review to assess SARS-CoV-2 seroprevalence and determinants in children worldwide., Methods: In this systematic review and meta-analysis study, we searched international and preprinted scientific databases from December 1, 2019 to July 10, 2022. Pooled seroprevalences were estimated according to World Health Organization (WHO) regions (at 95% confidence intervals, CIs) using random-effects meta-analyses. Associations with SARS-CoV-2 seroprevalence and sources of heterogeneity were investigated using sub-group and meta-regression analyses. The protocol used in this study has been registered in PROSPERO (CRD42022350833)., Findings: We included 247 studies involving 757,075 children from 70 countries. Seroprevalence estimates varied from 7.3% (5.8-9.1%) in the first wave of the COVID-19 pandemic to 37.6% (18.1-59.4%) in the fifth wave and 56.6% (52.8-60.5%) in the sixth wave. The highest seroprevalences in different pandemic waves were estimated for South-East Asia (17.9-81.8%) and African (17.2-66.1%) regions; while the lowest seroprevalence was estimated for the Western Pacific region (0.01-1.01%). Seroprevalence estimates were higher in children at older ages, in those living in underprivileged countries or regions, and in those of minority ethnic backgrounds., Interpretation: Our findings indicate that, by the end of 2021 and before the Omicron wave, around 50-70% of children globally were still susceptible to SARS-CoV-2 infection, clearly emphasising the need for more effective vaccines and better vaccination coverage among children and adolescents, particularly in developing countries and minority ethnic groups., Funding: None., Competing Interests: All authors declare no competing interests. Prof. Hotez is a co-inventor of a COVID-19 recombinant protein vaccine technology owned by Baylor College of Medicine (BCM) that was recently licensed by Baylor Ventures non-exclusively and with no patent restrictions to several companies committed to advance vaccines for low- and middle-income countries. These include Biological E (India–CORBEVAX) and BioFarma (Indonesia–INDOVAC), Incepta (Bangladesh). He has no involvement in license negotiations conducted by BCM. Similar to other research universities, a long-standing BCM policy provides its faculty and staff, who make discoveries and that result in a commercial license, a share of any royalty income. To date, BCM has not distributed any royalty income to the co-inventors on the COVID-19 recombinant protein vaccine technology., (© 2022 The Author(s).)

The recent dramatic increase in reported cases of porcine epidemic diarrhea (PED) in pig farms is a potential threat to the global swine industry. Therefore, the accurate diagnosis, serological monitoring, and surveillance of specific antibodies in pigs resulting from porcine epidemic diarrhea virus (PEDV) infection or vaccination would be essential in helping to control the spread of PED. We developed and validated an indirect enzyme-linked immunosorbent assay (ELISA) based on the recombinant membrane (M) protein of PEDV. To detect PEDV antibodies in eight herds, 382 serum samples were collected from sows that had been immunized with a PED vaccine, and screened using the developed ELISA in parallel with a serum neutralization (SN) assay. Of the tested samples, 276 were positive for the presence of PEDV antibodies according to both assays, while 98 were negative. An excellent agreement between the ELISA and the SN assay was observed (kappa = 0.947; 95% confidence interval = 0.910–0.984; McNemar's test, P = 0.727). No cross-reaction was detected for the developed ELISA with other coronaviruses or other common pig pathogens. The developed ELISA could be used for serological evaluation and indirect diagnosis of PED infection. [ABSTRACT FROM AUTHOR]