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Pneumococcal conjugate vaccines (PCVs) have proven to be the best way to prevent severe childhood pneumococcal disease but until recently have been difficult for many countries to afford sustainabl...

During a pandemic, the availability of specific pathogen free chicken eggs is a major bottleneck for up-scaling response to the demand for influenza vaccine. This has led us to explore the use of Madin-Darby Canine Kidney (MDCK) cells for the manufacture of live attenuated influenza vaccine (LAIV) that provides production flexibility and speed. The present study reports the comparison of the immunogenicity and efficacy of two MDCK-based LAIVs against two egg-based LAIVs prepared from the same pandemic potential strains of H5 and H7 subtypes after a single dose of the vaccine followed by a challenge with a homologous wild type strain. The vaccine strains have been generated by classical method of reassortment using the A/Leningrad/134/17/57 master donor strain. Additionally, a prime-boost regimen of the MDCK-based vaccine followed by a challenge with a homologous wild type strain for H5 and H7 immunized ferrets and also a heterologous wild type strain for the H5 immunized animals was studied. No difference in the hemagglutination inhibition and virus neutralization antibody titers against the homologous virus was observed following a single dose of either egg-based or MDCK-based H5 and H7 LAIV vaccine. A second dose of MDCK-based vaccine significantly boosted antibody titers in the vaccinated animals. Both a single dose or two doses of LAIV provided complete protection from lower respiratory tract infection and resulted in a significant reduction in the virus titers recovered from the throat, nasal turbinates and lungs after challenge with the homologous wild type strain. Protection from a challenge with a heterologous strain of H5 was also observed after two doses of the MDCK-based LAIVs. This data strongly supports the use of MDCK as a substrate for the manufacture of LAIV which ensures reliable quality, safety, production flexibility, speed and breadth of protection, features that are highly critical during a pandemic.

The linking of polysaccharide in glycoconjugate vaccine with carrier protein is an imperative step to develop a strong memory response. The excessive use of similar carrier protein known to result in bystander immunity warrants an urgent need for new carrier protein. The preparation of the glycoconjugate vaccine using cyanylation chemistry is to link the active cyanate ester site of polysaccharide with the carrier protein. In the present study, transferrin binding protein-B (Tbp-B) has been explored as a new carrier protein to develop in silico pneumococcal polysaccharide serotype-5 (PnPs-5) conjugate vaccine. The homology model of Tbp-B was constructed using the Prime module and stereochemically validated using ProSA, PDBsum and ProQ. The selected model revealed a Z-score of -5.6 within the X-ray region in ProSA analysis, LGscore: 9.776, and MaxSub: 0.8 in protein quality predictor suggesting its preferred use. Loop modeling and active site analysis followed by in silico PnPs-5 activation with cyanalyting agent CDAP was docked with Tbp-B using Glide module. The complex stability of cyanate esters with Tbp-B, analyzed by molecular dynamics (MD) simulation, revealed an average RMSD of 2.49 angstrom for its binding to the receptor. The RMSF values of cyanate ester-1, -2, and -3 were observed to be 1.06, 1.39 and 0.79 angstrom, respectively. The higher RMSF of 1.39 angstrom of cyanate ester-2 was further found unstable which corroborates its non-binding to the protein and also incurring conformational changes to a carrier protein. Molecular simulations revealed that cyanate ester-1 and cyanate ester-3 formed stable conjugates with carrier protein Tbp-B. Communicated by Ramaswamy H. Sarma

A high-quality and cost-effective purification procedure is one of the most important requirements for manufacturing glycoconjugate vaccines. The goal of the present work was to devise a method for removing impurities such as protein and nucleic acid from Streptococcus pneumoniae serotype 2 capsular polysaccharides (CPS). The use of hydrogen peroxide for the reduction of impurities of crude CPS was investigated. Centrifugation followed by filtration decreased protein contaminant of the hydrogen peroxide-treated CPS to meet the limit specified by WHO. The nucleic acid impurity remaining was removed by a further step of endonuclease treatment to yield the purified CPS. Characterization of purified CPS was evaluated by various analytical techniques including

Partial depolymerization of bacterial capsular polysaccharides (CPS) is an essential process carried out before its use as an antigenic preparation in a vaccine industry. Choice of CPS depolymerization methods depends on the process robustness, reproducibility, yield, retention of CPS bioactivity, etc. Partial depolymerization methods based on chemicals, enzymes, mechanical, thermal, etc. have been subject of many investigations before. Partial depolymerization of Streptococcus pneumoniae serotype 2 purified CPS was conducted by methods such as acid hydrolysis, microfluidization, ultrasonication, thermal and microwave. Partial depolymerization of the CPS was evaluated by size exclusion high performance liquid chromatography, whereas structural identity and conformity of CPS was ensured by

We conducted a phase 2, observer-blinded, randomized, controlled trial involving Malian children 12 to 16 months of age. Participants were assigned in a 2:2:1 ratio to receive nonadjuvanted NmCV-5, alum-adjuvanted NmCV-5, or the quadrivalent vaccine MenACWY-D, administered intramuscularly in two doses 12 weeks apart. Participants were followed for safety for 169 days. Immunogenicity was assessed with an assay for serum bactericidal antibody (SBA) with rabbit complement on days 0, 28, 84, and 112.A total of 376 participants underwent randomization, with 150 assigned to each NmCV-5 group and 76 to the MenACWY-D group; 362 participants received both doses of vaccine. A total of 1% of the participants in the nonadjuvanted NmCV-5 group, 1% of those in the adjuvanted NmCV-5 group, and 4% of those in the MenACWY-D group reported local solicited adverse events; 6%, 5%, and 7% of the participants, respectively, reported systemic solicited adverse events. An SBA titer of at least 128 was seen in 91 to 100% (for all five serotypes) of the participants in the NmCV-5 groups and in 36 to 99% (excluding serogroup X) of those in the MenACWY-D group at day 84 (before the second dose); the same threshold was met in 99 to 100% (for all five serotypes) of the participants in the NmCV-5 groups and in 92 to 100% (excluding serogroup X) of those in the MenACWY-D group at day 112. Immune responses to the nonadjuvanted and adjuvanted NmCV-5 formulations were similar.No safety concerns were identified with two doses of NmCV-5. A single dose of NmCV-5 elicited immune responses that were similar to those observed with two doses of MenACWY-D. Adjuvanted NmCV-5 provided no discernible benefit over nonadjuvanted NmCV-5. (Funded by the U.K. Foreign, Commonwealth, and Development Office; ClinicalTrials.gov number, NCT03295318.).

Towards achieving the goal of eliminating epidemic outbreaks of meningococcal disease in the African meningitis belt, a pentavalent glycoconjugate vaccine (NmCV-5) has been developed to protect against Neisseria meningitidis serogroups A, C, Y, W and X. MenA and X polysaccharides are conjugated to tetanus toxoid (TT) while MenC, Y and W polysaccharides are conjugated to recombinant cross reactive material 197 (rCRM197), a non-toxic genetic variant of diphtheria toxin. This study describes quality control testing performed by the manufacturer, Serum Institute of India Private Limited (SIIPL), and the independent control laboratory of the U.K. (NIBSC) on seven clinical lots of the vaccine to ensure its potency, purity, safety and consistency of its manufacturing. In addition to monitoring upstream-manufactured components, samples of drug substance, final drug product and stability samples were evaluated. This paper focuses on the comparison of the vaccine’s critical quality attributes and reviews key indicators of its stability and immunogenicity. Comparable results were obtained by the two laboratories demonstrating sufficient levels of polysaccharide O-acetylation, consistency in size of the bulk conjugate molecules, integrity of the conjugated saccharides in the drug substance and drug product, and acceptable endotoxin content in the final drug product. The freeze-dried vaccine in 5-dose vials was stable based on molecular sizing and free saccharide assays. Lot-to-lot manufacturing consistency was also demonstrated in preclinical studies for polysaccharide-specific IgG and complement-dependent serum bactericidal activity for each serogroup. This study demonstrates the high quality and stability of NmCV-5, which is now undergoing Phase 3 clinical trials in Africa and India.

The potency of all modern tissue culture human rabies vaccines is measured based on the National Institute of Health (NIH) potency test that is laborious, time-consuming, involves large test variations and requires sacrifice of large number of animals. To circumvent these limitations, several researchers and WHO expert working groups have discussed development of alternative in vitro methods to replace the NIH potency test. Although several immunochemical methods have been proposed to quantify rabies glycoprotein (G-protein) using multiple murine monoclonal antibodies, we report an In vitro competitive inhibition ELISA (CIA) method based on the use of a neutralizing rabies glycoprotein site III directed novel therapeutic human rabies monoclonal antibody (RAB1) that shows equivalence to the mice NIH potency test in recognition of neutralization site of the glycoprotein. In vitro potency testing of WHO 7th International Standard for rabies vaccine (IS) by CIA using RAB1 and In-house reference standard (IHRS) as a standard to assess its suitability for the assessment of validation parameters showed accurate and precise values with 0.98 and LLOQ of 0.125 IU/mL indicating sensitivity of the method. The method was found to be precise, robust and accurate to quantitate intact rabies glycoprotein in final vaccine and showed a strong correlation (Pearson's r = 0.81) with the NIH potency values of licensed Vero cell rabies vaccine. The CIA test using RAB1 was able to accurately quantitate degradation of rabies vaccine and assess loss in antigenicity of lyophilized and reconstituted liquid rabies vaccine under thermal stress conditions. The method was able to differentiate between potent and reduced potency vaccine samples. The new in vitro competitive inhibition ELISA method using RAB1 thus can be a valid alternative to the NIH test.

Cell culture based live attenuated influenza vaccines (LAIV) as an alternative to egg-based LAIV have been explored because of lack of easy access to SPF eggs for large scale production. In this study, feasibility of MDCK platform was assessed by including multiple LAIV strains covering both type A (H1 and H3) and type B seasonal strains as well as the candidate pandemic potential strains like A/H5 and A/H7 for the growth in MDCK cells. A risk assessment study was conducted on the cell banks to evaluate safety concerns related to tumorigenicity with a regulatory perspective. Tumorigenic potential of the MDCK cells was evaluated in nude mice (107cells/mouse) model system. The 50% tumor producing dose (TPD50) of MDCK cells was studied in SCID mice to determine the amount of cells required for induction of tumors. Further, we conducted an oncogenicity study in three sensitive rodent species as per the requirements specified in the WHO guidelines. We determined TPD50 value of 1.9 X 104 cells/mice through subcutaneous route. Our results suggest that, the intranasal route of administration of the cell culture based LAIV pose minimal to no risk of tumorigenicity associated with the host cells. Also, non-oncogenic nature of MDCK cells was demonstrated. Host cell DNA in the vaccine formulations was The present study clearly establishes the suitability of MDCK cells as a substrate for the manufacture of a safe and viable LAIV.

Bacterial lipopolysaccharide (LPS) responsible for endotoxin effect induces inflammatory reactions. The endotoxins are difficult to separate from the gram-negative polysaccharide (PS) during polysaccharide purification. The most common method to quantify LPS is the limulus amebocyte lysate (LAL) test which interferes with the agents used during PS purification. The gas chromatography-mass spectrometry (GC-MS) provides a suitable alternative by estimating lipid-A chain anchored 3-hydroxy fatty acid methyl ester (FAME) to estimate LPS however, there are no reports of its application in natural polysaccharides used for vaccine preparation. The transesterification of LPS and meningococcal PS yielded primary target 3-O-acetylated myristic acid which was detected by GC-MS and provided quantitative estimation of endotoxin. The GC-MS method was found in agreement with the LAL values showing lower endotoxin content 10Eu/µg in meningococcal C and Y serogroup polysaccharides in comparison to higher endotoxin 177-523 Eu/µg in meningococcal A, W and X serogroups. The high endotoxin content in purified polysaccharide was attributed to it being detected in its intermediate stage by GC-MS unlike the LAL test. Thus GC-MS serves as a valuable method for endotoxin monitoring and quantitation in gram-negative meningococcal intermediate and purified PS during vaccine preparation.

Foetal Bovine Serum (FBS) and porcine trypsin are one of the essential raw materials used in the manufacturing of cell culture based viral vaccines. Being from animal origin, these raw materials can potentially contaminate the final product by known or unknown adventitious agents. The issue is more serious in case of live attenuated viral vaccines, where there is no inactivation step which can take care of such adventitious agents. It is essential to design production processes which can offer maximum viral clearance potential for animal origin products. Ultraviolet-C irradiation is known to inactivate various adventitious viral agents; however there are limited studies on ultraviolet inactivation of viruses in liquid media. We obtained a recently developed UVivatec ultraviolet-C (UV-C) irradiation based viral clearance system for evaluating its efficacy to inactivate selected model viruses. This system has a unique design with spiral path of liquid allowing maximum exposure to UV-C light of a short wavelength of 254 nm. Five live attenuated vaccine viruses and four other model viruses were spiked in tissue culture media and exposed to UV-C irradiation. The pre and post UV-C irradiation samples were analyzed for virus content to find out the extent of inactivation of various viruses. These experiments showed substantial log reduction for the majority of the viruses with few exceptions based on the characteristics of these viruses. Having known the effect of UV irradiation on protein structure, we also evaluated the post irradiation samples of culture media for growth promoting properties using one of the most fastidious human diploid cells (MRC-5). UV-C exposure did not show any notable impact on the nutritional properties of culture media. The use of an UV-C irradiation based system is considered to be promising approach to mitigate the risk of adventitious agents in cell culture media arising through animal derived products.

Background Lack of access to rabies immunoglobulin (RIG) contributes to high rabies mortality. A recombinant human monoclonal antibody (SII RMAb) was tested in a postexposure prophylaxis (PEP) regimen in comparison with a human RIG (HRIG)-containing PEP regimen. Methods This was a phase 2/3, randomized, single-blind, noninferiority study conducted in 200 participants with World Health Organization category III suspected rabies exposures. Participants received either SII RMAb or HRIG (1:1 ratio) in wounds and, if required, intramuscularly on day 0, along with 5 doses of rabies vaccine intramuscualarly on days 0, 3, 7, 14 and 28. The primary endpoint was the ratio of the day 14 geometric mean concentration (GMC) of rabies virus neutralizing activity (RVNA) as measured by rapid fluorescent focus inhibition test for SII RMAb recipients relative to HRIG recipients. Results One hundred ninety-nine participants received SII RMAb (n = 101) or HRIG (n = 98) and at least 1 dose of vaccine. The day 14 GMC ratio of RVNA for the SII RMAb group relative to the HRIG group was 4.23 (96.9018% confidence interval [CI], 2.59-6.94) with a GMC of of 24.90 IU/mL (95% CI, 18.94-32.74) for SII RMAb recipients and 5.88 IU/mL (95% CI, 4.11-8.41) for HRIG recipients. The majority of local injection site and systemic adverse reactions reported from both groups were mild to moderate in severity. Conclusions A PEP regimen containing SII RMAb was safe and demonstrated noninferiority to HRIG PEP in RVNA production. The novel monoclonal potentially offers a safe and potent alternative for the passive component of PEP and could significantly improve the management of bites from suspected rabid animals. Clincical trials registration CTRI/2012/05/002709.

Background A more affordable pneumococcal conjugate vaccine (PCV) that provides comparable protection to current PCVs is needed to ensure sustainable access in resource-limited settings. Serum Institute of India Pvt. Ltd.’s PCV candidate (SIIPL-PCV) has the potential to meet this need as manufacturing efficiency has been optimized and the vaccine targets the most prevalent disease-causing serotypes in Africa and Asia. We report SIIPL-PCV’s safety, tolerability, and immunogenicity in adults, toddlers, and infants in The Gambia. Methods This phase 1/2, randomized, double-blind trial sequentially enrolled 34 PCV-naive adults (18–40 years old), 112 PCV (Prevenar 13® [PCV13])-primed toddlers (12–15 months old), and 200 PCV-naive infants (6–8 weeks old), who were randomized (1:1) to receive SIIPL-PCV or a licensed comparator vaccine. Infants received three-doses of SIIPL-PCV or PCV13 at 6, 10, and 14 weeks of age co-administered with routine Expanded Program on Immunization (EPI) vaccines. Reactogenicity was solicited through seven-days post-vaccination; unsolicited adverse events (AEs) were assessed throughout the study. The safety and immunogenicity of a matching booster at 10–14 months of age were evaluated in a subset of 96 infants. Immune responses were evaluated post-primary and pre- and post-booster vaccinations. Results Reactogenicity was primarily mild-to-moderate in severity. In infants, the most common solicited reactions were injection-site tenderness and fever, with no meaningful treatment-group differences. There were no serious or severe vaccine-related AEs and no meaningful trends in SAEs, vaccine-related AEs, or overall AEs. Infant post-primary seroresponse rates (IgG level ≥ 0.35 µg/mL) were ≥89% for all serotypes except 6A (79%) in the SIIPL-PCV group. IgG GMCs were >1 µg/mL for all serotypes in both SIIPL-PCV and PCV13 groups. Post-booster GMCs were comparable between groups. Conclusion SIIPL-PCV was well-tolerated, had an acceptable safety profile, and was immunogenic for all vaccine serotypes. Results support the evaluation of SIIPL-PCV in a phase 3 non-inferiority trial. Clinicaltrials.gov: NCT02308540 .

Sodium dodecyl sulfate (SDS) is a commonly used surfactant in protein solubilization and also during the polysaccharide purification. A GC-MS method has been developed to quantitate residual SDS in meningococcal polysaccharide serogroups A,C,W,Y and X circumventing the need of spectroscopic assays and HPLC based methods which are either unstable or requires the confirmation by MS. The developed method is based on quantitative conversion of SDS to 1-dodecanol at elevated temperature. Meningococcal polysaccharides and SDS standards were treated with methanolic-HCl and extracted in n-Hexane. The conversion of SDS to 1-dodecanol was confirmed by mass spectra and separation was achieved using a DB-5ms column. The mass spectral analysis of 1-dodecanol showed characteristic ions at m/z 168, 140 and 125. The GC-MS method validation performed on intermediate and purified meningococcal polysaccharides showed linearity with r2 > 0.99 over the concentration range of 2.5–200 μg/ml with LOD and LOQ of 1.27 and 3.85 respectively. The method was found to be precise, robust and accurate with spike recovery ranging 83–117%. The GC-MS method can be used in the quantitation of residual SDS during polysaccharide purification and provides valuable information about consistency of polysaccharide manufacturing process for development of pentavalent meningococcal conjugate vaccine.

Development of an effective purification process in order to provide low cost and high-quality vaccine is the necessity of glycoconjugate vaccine manufacturing industries. In the present study, we have attempted to develop a method for simultaneous purification and depolymerization process for capsular polysaccharides (CPS) derived from Streptococcus pneumoniae serotype 2. Trifluoroacetic acid (TFA) was used to precipitate impurities which were then removed by centrifugation. It was observed that the TFA treatment could simultaneously depolymerize the CPS and purify it. The purified and depolymerized CPS was analyzed for its purity, structural identity and conformity, molecular size, antigenicity to meet desired quality specifications. The obtained results showed that the purification and depolymerization of S. pneumoniae serotype 2 CPS did not affect the antigenicity of CPS.

Polysorbates are the most versatile and common surfactants used as protein stabilizers. Analysis of residual polysorbate 80 (PS 80) in conjugate vaccine is challenging due to complexity of conjugate matrices and heterogeneity of the structure of the PS 80 analyte. The direct approach using high-performance liquid chromatography-evaporative light scattering detector (HPLC-ELSD) and gas chromatography-mass spectrometry (GC–MS) that is based on oleic acid methyl ester formation followed by transesterification have been evaluated to quantitate residual PS 80 in meningococcal serogroups A, C, W, Y and X bulk conjugates. HPLC-ELSD method was observed to be less sensitive in comparison to the GC-MS method. The GC-MS method showed promise for quantitation of residual polysorbate 80 with advantages of higher sensitivity, simple sample preparation and mass spectral characterization compared to methods reported to literature. The oleic acid methyl ester was solubilized in hexane and injected in GC-MS to separate on highly polar capillary CP-WAX 52 CB Column. The mass spectral analysis showed characteristic ions at m/z 180, 222 and 264. The method was validated with linearity r2 > 0.99 over the concentration range of 0.5 to 100 μg/mL with LOD and LOQ of 0.3 and 0.91 respectively using PS 80 standard. The GC–MS method provides a simple, fast and label free technique for the precise quantitation of residual PS 80 in meningococcal bulk conjugate vaccine sample, achieved with accuracy between 85–105%.

A parenteral inactivated rotavirus vaccine (IRV) in development could address three problems with current live oral rotavirus vaccines (ORV): their lower efficacy in low and middle-income countries (LMICs), lingering concerns about their association with intussusception, and their requirement for a separate supply chain with large volume cold storage. Adding a new parenteral IRV to the current schedule of childhood immunizations would be more acceptable if it could be combined with another injectable vaccine such as inactivated polio vaccine (IPV). Current plans for polio eradication call for phasing out oral polio vaccine (OPV) and transitioning to IPV, initially in LMICs as a single dose booster after two doses of OPV and ultimately as a two dose schedule. Today in many LMICs, IPV is administered as a standalone vaccine, which involves a separate cold chain and is relatively costly. We therefore tested in two animal models formulations of IPV with IRV to determine whether co-administration might interfere with the immune response to each product and spare antigen dose for both vaccines. Our results demonstrate that IRV when adjuvanted with alum and administered alone or in combination with IPV did not impair the immune responses to either rotavirus or poliovirus serotypes 1, 2 and 3. Similarly, IPV when formulated and administered alone or together with IRV induced comparable levels of neutralizing antibody to poliovirus type 1, 2 and 3. Furthermore, comparable antibody titers were observed in animals vaccinated with low, middle or high dose of IPV or IRV in combination. This dose sparing and the lack of interference between IPV and IRV administered together represent another step to support the further development of this novel combination vaccine for children.

A ferret challenge study was conducted to address the efficacy of the egg-based and Madin-Darby canine kidney (MDCK)-based live attenuated influenza vaccine (LAIV) strains. Vaccines derived as 6:2 reassortants from the A/Leningrad/134/17/57 master donor strain and the HA and NA components from the A/California/07/2009 (A/Cal)- and A/Michigan/45/2015 (A/Mich)-like strains of type A H1N1 influenza virus were used in the study. Monovalent, trivalent and quadrivalent formulations of the LAIV containing either of the two H1N1 strains were analysed. A total of ten groups of six animals each were immunised intranasally (i.n.) with a single dose of 0.5-ml vaccine formulation or placebo and challenged on day 28 with the homologous wild-type A/Cal or A/Mich strain. Immune response post immunisation and virus replication post challenge were studied. Both the strains derived from embryonated eggs or MDCK cells, irrespective of the vaccine valency, were capable of rendering complete protection from virus replication in the lung. The A/Mich vaccine strain showed higher immune titres and efficacy than the A/Cal vaccine strain in all the vaccine formulations. The haemagglutination inhibition and virus neutralisation antibody titres were induced, and the reduction in the virus load in the respiratory tract was observed to be higher in animals treated with the monovalent formulation compared to the trivalent and quadrivalent formulations. Overall, it appears that the monovalent formulations render better protection from infection and would therefore be the best candidate during a pandemic.

Summary Background Invasive meningococcal disease is an important public health problem, especially in sub-Saharan Africa. After introduction of MenAfriVac in 2010, Neisseria meningitidis serogroup A disease has been almost eliminated from the region. However, serogroups C, W, Y, and X continue to cause disease outbreaks. We assessed the NmCV-5 pentavalent meningococcal conjugate vaccine targeting A, C, Y, W, and X serogroups in a first-in-man, phase 1 study. Methods We did a single-centre, double-blind, randomised controlled trial at a research clinic in Baltimore (MD, USA). Participants were healthy adults aged 18–45 years with no history of meningococcal vaccination or previous meningococcal infection. We randomly assigned participants (1:1:1) by an SAS-generated random schedule to a single, 0·5 mL, intramuscular injection of aluminium-phosphate adjuvanted NmCV-5, non-adjuvanted NmCV-5, or control (the quadrivalent meningococcal conjugate vaccine Menactra). The randomisation sequence used a permuted block design with randomly chosen block sizes of three and six. The vaccines were prepared, labelled, and administered with procedures to ensure participants and study personnel remained masked to treatment. After vaccination, participants were observed in the clinic for 60 min for adverse reactions. Participants recorded daily temperature and injection site or systemic reactions at home and returned to the clinic for follow-up visits on days 7, 28, and 84 for safety assessments; blood samples were also collected on day 7 for safety laboratory assessment. A phone call contact was made 6 months after vaccination. Serum was collected before vaccination and 28 days after vaccination for immunological assessment with a rabbit complement-dependent serum bactericidal antibody (rSBA) assay. The primary objective was an intention-to-treat assessment of safety, measuring local and systemic reactogenicity over 7 days, unsolicited adverse events through 28 days, and serious adverse events over 6 months. The secondary objective for the assessment of immunogenicity, was a per-protocol analysis of rSBA before and 28 days after vaccination. This trial is registered with ClinicalTrials.gov , number NCT02810340 . Findings Between Aug 17, 2016, and Feb 16, 2017, we assigned 20 participants to each vaccine. All vaccines were well-tolerated. Pain was the most common local reaction, occurring in 12 (60%), ten (50%), and seven (35%) participants in the adjuvanted NmCV-5, non-adjuvanted NmCV-5, and control groups, respectively. Headache was the most common systemic reaction, occurring in five (25%), three (15%), and three (15%), respectively. Most solicited reactogenicity adverse reactions were mild (60 [74%] of 81) and all were self-limiting. None of the differences in proportions of individuals with each solicited reaction was significant (p>0·300 for all comparisons) between the three vaccination groups. There were no serious adverse events and 19 unsolicited non-serious adverse events in 14 (23%) participants. Both adjuvanted and non-adjuvanted NmCV-5 elicited high rSBA titres against all five meningococcal serogroups. The pre-vaccination geometric mean titres (GMTs) ranged from 3·36 to 53·80 for the control, from 6·28 to 187·00 for the adjuvanted vaccine, and from 4·29 to 350·00 for the non-adjuvanted vaccine, and the post-vaccination GMT ranged from 3·14 to 3214 for the control, from 1351 to 8192 for the adjuvanted vaccine, and from 1607 to 11 191 for the non-adjuvanted vaccine. Predicted seroprotective responses (ie, an increase in rSBA titres of eight times or more) for the adjuvanted and non-adjuvanted NmCV-5 were similar to control responses for all five serogroups. Interpretation The adjuvanted and non-adjuvanted NmCV-5 vaccines were well tolerated and did not produce concerning adverse effects and resulted in immune responses that are predicted to confer protection against all five targeted serogroups of invasive meningococcal disease. Further clinical testing of NmCV-5 is ongoing, and additional clinical trials are necessary to confirm the safety and immunogenicity of NmCV-5 in target populations. Funding UK Department for International Development.

Highlights • Pentavalent reassortant rotavirus vaccine was tested for efficacy in infants. • The vaccine (BRV-PV) showed excellent tolerability and a good safety profile. • Primary analysis efficacy was 36% against SRVGE and up to 60.5% against VSRVGE. • The efficacy through 2 years of age was 39.5% (SRVGE) and 54.7% (VSRVGE). • The intent to treat analyses confirmed all the per protocol analyses., Rotavirus is the most common cause of moderate-to-severe infant diarrhoea in developing countries, resulting in enormous morbidity, mortality, and economic burden. A bovine-human reassortant pentavalent rotavirus vaccine (BRV-PV) targeting the globally most common strains was developed in India and tested in a randomized, double-blind, placebo-controlled end-point driven Phase III efficacy clinical trial implemented at six sites across India. Infants 6 to 8 weeks of age were randomized (1:1) to receive three oral doses of BRV-PV or placebo at 6, 10, and 14 weeks of age along with routine vaccines. Home visit surveillance was conducted to detect severe rotavirus gastroenteritis (SRVGE) and safety outcomes until the children reached two years of age. A total of 3749 infants received BRV-PV while 3751 received placebo. At the time of the primary end-point (when the minimum number of cases needed for analysis were accrued) the vaccine efficacy against SRVGE was 36% (95% CI 11.7, 53.6, p = 0.0067) in the per protocol (PP) analysis, and 41.9% (95% CI 21.1, 57.3, p = 0.0005) in the intent to treat (ITT) analysis. Vaccine efficacy over the entire follow-up period (until children reached two years of age) was 39.5% (95% CI 26.7, 50, p

Introduction: Rabies is a 100% fatal disease with significant disease burden in Asia and Africa but preventable with vaccines and immunoglobulins. There are very few WHO prequalified cell culture derived rabies vaccines available globally for use in humans. We have developed a new purified vero cell rabies vaccine (Rabivax-S) to meet this demand.Areas covered: In this review, we have described the detailed manufacturing process of Rabivax-S and summary of preclinical and clinical development based on the data generated in-house.Expert commentary: Rabivax-S has been developed on Vero ATCC CCL81 cells using Pitman Moore (PM3218) strain. Following all the GMP requirements the vaccine was tested in GLP toxicology studies. Further it underwent clinical trials in preexposure and postexposure settings and was found safe and immunogenic.

Background Measles is a highly infectious respiratory disease which causes 122,000 deaths annually. Although measles vaccine is extremely safe and effective, vaccine coverage could be improved by a vaccine that is more easily administered and transported. We developed an inhalable dry powder measles vaccine (MVDP) and two delivery devices, and demonstrated safety, immunogenicity, and efficacy of the vaccine in preclinical studies. Here we report the first clinical trial of MVDP delivered by inhalation. Methodology Sixty adult males aged 18 to 45 years, seropositive for measles antibody, were enrolled in this controlled Phase I clinical study. Subjects were randomly assigned in 1:1:1 ratio to receive either MVDP by Puffhaler® or by Solovent™ devices or the licensed subcutaneous measles vaccine. Adverse events (AEs) were recorded with diary cards until day 28 post-vaccination and subjects were followed for 180 days post-vaccination to assess potential serious long term adverse events. Measles antibody was measured 7 days before vaccination and at days 21 and 77 after vaccination by ELISA and a plaque reduction neutralization test. Results All subjects completed the study according to protocol. Most subjects had high levels of baseline measles antibody. No adverse events were reported. MVDP produced serologic responses similar to subcutaneous vaccination. Conclusions MVDP was well tolerated in all subjects. Most subjects had high baseline measles antibody titer which limited ability to measure the serologic responses, and may have limited the adverse events following vaccination. Additional studies in subjects without pre-existing measles antibody are needed to further elucidate the safety and immunogenicity of MVDP.

Rubella infection though a mild infection, may cause foetal death or a variety of congenital anomalies. Multiple sero-surveys confirmed that 5–10% women are unexposed to natural or vaccinated rubella virus and remain susceptible to rubella infection. The current study was conducted in 600 girls, aged 18–24 y from Symbiosis International University (SIU), Pune, India to assess their sero-status against rubella infection and to estimate the immunogenicity of rubella vaccine in achieving sero-protective antibody titres. Prior to administration of a single i.m. dose of rubella vaccine (R-vac®) to eligible participants, blood sample (pre-vaccination) was collected. During the 4–6 weeks observation period, adverse events were noted. Then, a second blood sample (post-vaccination) was collected. Significant increase was noted in sero-protection response, viz., 98.6% (post-vaccination) vis-à-vis 66.5% (pre-vaccination); Geometric mean titer (GMT) was significantly higher post-vaccination. Effective measures to introduce rubella vaccination on a larger scale need to be undertaken. An immunization policy with mandatory rubella vaccination for all girls in the reproductive age group and its inclusion in national immunization schedule is highly desirable.

A bovine rotavirus pentavalent vaccine (BRV-PV) containing rotavirus human-bovine (UK) reassortant strains of serotype G1, G2, G3, G4 and G9 has been developed by the Serum Institute of India Ltd, in collaboration with the National Institute of Allergy and Infectious Diseases (NIAID), USA. The vaccine underwent animal toxicity studies and Phase I and II studies in adults, toddlers and infants. It has been found safe and immunogenic and will undergo a large Phase III study to assess efficacy against severe rotavirus gastroenteritis.

Vaccines currently available across the globe are stored and transported in a continuous cold-chain at 2-8°C or below -20°C. A temperature excursion outside this range affects the potency of the vaccines. Such vaccines need to be discarded leading wastage. The Rotavirus disease burden is predominantly reported in developing and low-income countries and therefore, has entered or poised to enter their national immunization programs. These countries already have several limitations for effective storage, maintenance and distribution of vaccines in a cold-chain and this introduction is expected to further stress this fragile ecosystem. To help mitigate the cold chain related issues, SIIPL has developed a thermostable rotavirus vaccine ROTASIIL® which can be stored at a temperature below 25°C for 36months, completely by-passing the standard 2-8°C cold storages. In addition it has the capability to withstand temperatures of 37°C and 40°C for 18months and short term exposure to 55°C. It can also tolerate a temperature shock of being thawed from an extreme cold temperature of -20°C to a high temperature of 42°C. The vaccine contains serotypes G1, G2, G3, G4 and G9 (UK-Bovine reassortant strains procured from National Institute of Health-USA). The vaccine is recently licensed in India.

Background Rabies is a 100% fatal disease but preventable with vaccines and immunoglobulins. We have developed a new purified vero cell rabies vaccine (Rabivax-S) and evaluated its safety and immunogenicity in post-exposure prophylaxis by intramuscular (IM) and intradermal (ID) routes. Methods This was a randomized active-controlled non-inferiority study in 180 individuals (age 5 years and above) with suspected rabies exposure (90 each with WHO Category II and Category III exposures). The participants received either Rabivax-S (1 mL IM; five doses), Rabivax-S (0.1 mL ID; eight doses) or purified chick embryo cell vaccine (PCEC, Rabipur®) (1 mL IM; five doses). The IM doses were given on Day 0, 3, 7, 14 and 28 while the ID doses were given on days 0, 3, 7 and 28. Category III patients also received a human rabies immunoglobulin (HRIG) on Day 0. Adverse events (AEs) were recorded with diary cards till day 42. Rabies neutralizing antibody levels were measured on day 0, 7, 14, 28 and 42. Results In both the category II and III patients, the geometric mean concentration (GMC) ratios of Rabivax-S IM and Rabivax-S ID groups to PCEC IM were more than 1, thus proving the non-inferiority. GMCs were similar or higher in Rabivax-S groups at all the time points. Seroresponse against rabies (RFFIT titre ⩾ 0.5 IU/mL) was achieved in all participants. Mostly mild local and systemic adverse events were reported across the three groups and all resolved without sequelae. Conclusions Rabivax-S was well tolerated and showed immunogenicity comparable to a licensed rabies vaccine by both IM and ID routes in post-exposure prophylaxis. Registry No.: CTRI/2012/11/003135

The analysis of residual sodium deoxycholate (DOC); a detergent of biological origin used in manufacturing of polysaccharide vaccines is challenging due to complex sample matrices and the lack of suitable methods. Here we report, rapid and sensitive high-performance liquid chromatography-refractive index (HPLC-RI) and tandem mass spectrometry (HPLC-MS/MS) methods for estimation of residual DOC in pneumococcal polysaccharides. For HPLC-RI method, separation was achieved using Luna C18 column and mobile phase compositions of acetonitrile: methanol: 20 mM sodium acetate (60:05:35% v/v). For HPLC-MS/MS method, separation was achieved using a Hypersil BDS C18 column with gradient elution of methanol and water (0.1% formic acid). MS/MS method showed linearity (r2 = 0.997) over the range of 10-320 ng/mL with limits of detection (LOD) and lower limit of quantitation (LOQ) of 3 and 10 ng/mL respectively. Precision (% RSD) and accuracy (% recovery) for both methods were in the range of 0.74-8.29% and 82.33-117.86% respectively. Sample matrices interferences were addressed following novel sample clean-up method based on liquid-liquid extraction. Both methods enabled traceable quantitation of DOC in intermediate and purified pneumococcal polysaccharides of serotypes: 1, 5, 6A, 6B, 7F, 9V, 14, 19A, 19F and 23F.

Introduction: Serologic surveys conducted in different countries indicate that rubella is a worldwide infection. Several such sero surveys conducted in India have also confirmed that 6-47% of women are susceptible to rubella infection. The current study was conducted on 1,329 female adolescents in 12 districts of Maharashtra, India, to assess their serological status in terms of rubella exposure. Methodology: After enrollment, a pre-vaccination blood sample was collected from the participants followed by rubella vaccination (R-vac). Adverse events were monitored for the next 6-8 weeks, at which time a post-vaccination sample was collected. Results: Pre-vaccination rubella immunity was higher in the urban (80.2%) population compared to the rural (73.1%) population. Following R-vac vaccination, out of 1,159 participants who completed the study, all (100%) in the urban and 99.5% of participants in the rural area developed antibodies against rubella. Conclusion: Substantial numbers of women reach childbearing age without immunity against rubella and thus are at a risk of passing the infection to their fetuses, who can then develop subsequent congenital defects leading to congenital rubella syndrome (CRS). An immunization policy recommending vaccination with rubella or rubella containing vaccine is highly desirable to prevent rubella and CRS.

In the event of a highly pathogenic influenza pandemic, the Indian subcontinent would need 1.2 billion doses of vaccine to immunize its entire population, double if two doses were required to assure immunity. Serum Institute of India Limited (SII) thus became one of six initial grantees of the World Health Organization (WHO) technology transfer initiative to create capacity in developing countries to manufacture H5N1 pandemic influenza vaccine. At the outbreak of the A(H1N1) 2009 influenza pandemic, experience gained from the H5N1 project was used to develop a live attenuated influenza vaccine (LAIV), since this was the only option for the level of surge capacity required for a large-scale immunization campaign in India. SII took

It is predicted that in case of an influenza pandemic, there will be a significant gap between potentially available vaccine supply and international demand. This paved the way for a WHO Global Pandemic Influenza Action Plan (GAP) aiming at increasing the world's production capacity for pandemic vaccine. In November 2006, six developing country manufacturers were awarded grants either to develop processes for production of inactivated or live attenuated seasonal and/or H5N1 influenza vaccines or for establishing filling facilities using imported antigens. In April 2009, spread of a new H1N1 influenza virus was identified which took a pandemic form. This paper gives an overview of influenza vaccine capacity building of developing country's manufacturers identified in WHO's GAP. Further, an account of developments at Serum Institute of India Limited (SIIL), one of recipients of WHO grant to develop pandemic influenza vaccine, are presented as a case study. Such initiatives have strengthened developing country vaccine manufacturers ability to respond to a pandemic situation in the future.

Standards for vaccine production have been increasing at a rapid rate. Current standards of good manufacturing practice (GMP) had been thought to be out of the reach of developing country vaccine producers, many of whom are in the public sector, overseen by unvalidated national regulatory authorities (NRAs). With the advent of the GMP regulations in 1963 and their application to vaccine production, even many industrialized country manufacturers with stringent NRA oversight had difficulties. This article assesses the ability of developing country manufacturers to meet GMP by the only currently available global indicator: WHO prequalification. As recently as 1996, no developing country NRA was considered able to enforce GMP compliance. That number increased to four in 2002 and six in 2006, with a concomitant increase in the number of manufacturers considered to be operating to GMP standards. Examples of the difficulties faced by manufacturers in achieving this are given, as well as implications for the future vaccine market.

Mumps epidemics in Canada and the United States prompted us to review evidence for the effectiveness of 5 different vaccine strains. Early trials with the Jeryl Lynn vaccine strain demonstrated an efficacy of approximately 95%, but in epidemic conditions, the effectiveness has been as low as 62%; this is still considerably better than the effectiveness of another safe strain, Rubini (which has an effectiveness of close to 0% in epidemic conditions). The Urabe vaccine strain has an effectiveness of 54%-87% but is prone to cause aseptic meningitis. Little epidemiological information is available for other vaccines. The Leningrad-Zagreb vaccine strain, which is widely used in developing countries and costs a fraction of what vaccines cost in the developed world, seems to have encouraging results; in 1 study, the effectiveness of this vaccine exceeded 95%. Aseptic meningitis has also been reported in association with this vaccine, but the benign nature of the associated meningitis was shown recently in Croatia. Also, the Leningrad-3 strain seems to be effective but causes less-benign meningitis. No mumps vaccine equals the best vaccines in quality, but the virtually complete safety of some strains may not offset their low effectiveness. Epidemiological data are pivotal in mumps, because serological testing is subject to many interpretation problems.

Mumps is an acute infectious disease caused by mumps virus, a member of the family Paramyxoviridae. With the implementation of vaccination programs, mumps infection is under control. However, due to resurgence of mumps epidemics, there is a renewed interest in understanding the antigenic diversity of mumps virus. Hemagglutinin–neuraminidase (HN) is the major surface antigen and is known to elicit neutralizing antibodies. Mutational analysis of HN of wild-type and vaccine strains revealed that the hypervariable positions are distributed over the entire length with no detectable pattern. In the absence of experimentally derived 3D structure data, the structure of HN protein of mumps virus was predicted using homology modeling. Mutations mapped on the predicted structures were found to cluster on one of the surfaces. A predicted conformational epitope encompasses experimentally characterized epitopes suggesting that it is a major site for neutralization. These analyses provide rationale for strain specificity, antigenic diversity and varying efficacy of mumps vaccines.

Background Aerosolized vaccine can be used as a needle-free method of immunization against measles, a disease that remains a major cause of illness and death. Data on the immunogenicity of aerosolized vaccine against measles in children are inconsistent. Methods We conducted an open-label noninferiority trial involving children 9.0 to 11.9 months of age in India who were eligible to receive a first dose of measles vaccine. Children were randomly assigned to receive a single dose of vaccine by means of either aerosol inhalation or a subcutaneous injection. The primary end points were seropositivity for antibodies against measles and adverse events 91 days after vaccination. The noninferiority margin was 5 percentage points. Results A total of 1001 children were assigned to receive aerosolized vaccine, and 1003 children were assigned to receive subcutaneous vaccine; 1956 of all the children (97.6%) were followed to day 91, but outcome data were missing for 331 children because of thawed specimens. In the per-protocol population, data on 1560 of 2004 children (77.8%) could be evaluated. At day 91, a total of 662 of 775 children (85.4%; 95% confidence interval [CI], 82.5 to 88.0) in the aerosol group, as compared with 743 of 785 children (94.6%; 95% CI, 92.7 to 96.1) in the subcutaneous group, were seropositive, a difference of -9.2 percentage points (95% CI, -12.2 to -6.3). Findings were similar in the full-analysis set (673 of 788 children in the aerosol group [85.4%] and 754 of 796 children in the subcutaneous group [94.7%] were seropositive at day 91, a difference of -9.3 percentage points [95% CI, -12.3 to -6.4]) and after multiple imputation of missing results. No serious adverse events were attributable to measles vaccination. Adverse-event profiles were similar in the two groups. Conclusions Aerosolized vaccine against measles was immunogenic, but, at the prespecified margin, the aerosolized vaccine was inferior to the subcutaneous vaccine with respect to the rate of seropositivity. (Funded by the Bill and Melinda Gates Foundation; Measles Aerosol Vaccine Project Clinical Trials Registry-India number, CTRI/2009/091/000673 .).

Disposable-syringe jet injectors (DSJIs) with single-use, auto disable, needle-free syringes offer the opportunity to avoid hazards associated with injection using a needle and syringe. Clinical studies have evaluated DSJIs for vaccine delivery, but most studies have focused on inactivated, subunit, or DNA vaccines. Questions have been raised about possible damage to live attenuated viral vaccines by forces generated during the jet injection process. This study examines the effect of jet injection on the integrity of measles, mumps, and rubella vaccine (MMR), measured by viral RNA content and infectivity. Three models of DSJIs were evaluated, each generating a different ejection force. Following jet injection, the RNA content for each of the vaccine components was measured using RT-qPCR immediately after injection and following passage in Vero cells. Jet injection was performed with and without pig skin as a simulation of human skin. There was little to no reduction of RNA content immediately following jet injection with any of the three DSJIs. Samples passaged in Vero cells showed no loss in infectivity of the measles vaccine following jet injection. Mumps vaccine consistently showed increased replication following jet injection. Rubella vaccine showed no loss after jet injection alone but some infectivity loss following injection through pig skin with two of the devices. Overall, these data demonstrated that forces exerted on a live attenuated MMR vaccine did not compromise vaccine infectivity. The bench model and protocol used in this study can be applied to evaluate the impact of jet injection on other live virus vaccines.

This mini-review aims to focus on the changing trend in the industry towards the type of cell substrates being used for viral vaccine production.

Influenza virus evades host immunity through antigenic drift and shift, and continues to circulate in the human population causing periodic outbreaks including the recent 2009 pandemic. A large segment of the population was potentially susceptible to this novel strain of virus. Historically, monoclonal antibodies (MAbs) have been fundamental tools for diagnosis and epitope mapping of influenza viruses and their importance as an alternate treatment option is also being realized. The current study describes isolation of a high affinity (K-D = 2.1 +/- 0.4 pM) murine MAb, MA2077 that binds specifically to the hemagglutinin (HA) surface glycoprotein of the pandemic virus. The antibody neutralized the 2009 pandemic H1N1 virus in an in vitro microneutralization assay (IC50 = 0.08 mu g/ml). MA2077 also showed hemagglutination inhibition activity (HI titre of 0.50 mu g/ml) against the pandemic virus. In a competition ELISA, MA2077 competed with the binding site of the human MAb, 2D1 (isolated from a survivor of the 1918 Spanish flu pandemic) on pandemic H1N1 HA. Epitope mapping studies using yeast cell-surface display of a stable HA1 fragment, wherein `Sa' and `Sb' sites were independently mutated, localized the binding site of MA2077 within the `Sa' antigenic site. These studies will facilitate our understanding of antigen antibody interaction in the context of neutralization of the pandemic influenza virus.

A live attenuated pandemic H1N1 influenza vaccine was developed in India. A post marketing surveillance was conducted retrospectively in healthy individuals (³ 3 years) who were vaccinated intranasally around one year before. After consent, the subjects recorded adverse events developing within 42 days. Among 7565 individuals (3 - 85 years), a total of 81 solicited adverse reactions (1%) were reported in 49 subjects (0.65%). The reactions included mild to moderate respiratory symptoms. No H1N1 case was encountered during one year postvaccination. The data show the safety of the live attenuated influenza vaccine platform developed in India.

Live attenuated influenza vaccines (LAIVs) targeting seasonal influenza are produced in embryonated eggs and formulated as a trivalent preparation of three live attenuated vaccine strains, one A(H1N1) strain, one A(H3N2) strain and one type B strain. In this study, we describe an egg-based potency assay for estimating the 50% Egg infectious dose (EID50) of individual strains in the trivalent preparation by selective neutralisation of two strains and then estimating the infective titres of the non-neutralised strain. The test is highly specific, and no cross interference of heterologous antisera is observed in the estimation of individual titres. Individual strains with titres in the range of 6.5-7.0 log EID50 per 0.5 ml show intra-assay and inter-assay coefficients of variance ranging from 1.25% to 2.95%. This assay was developed to establish a simple, reliable and inexpensive egg-based assay for estimating the potency of individual strains in a trivalent preparation.

The advent of the H1N1 influenza pandemic (pH1N1) in 2009 triggered the rapid production of pandemic influenza vaccines, since seasonal influenza vaccines were expected and demonstrated not to provide significant cross-protection against the newly emerged pandemic virus. To increase vaccine production capacity and further evaluate the effectiveness of different candidate pandemic influenza vaccines, the World Health Organization stimulated the evaluation of different vaccination concepts including the use of live attenuated influenza vaccines (LAIVs). Therefore, we have immunized ferrets intranasally with a single dose of pH1N1-LAIV from different manufacturers. They all induced adequate serum HI antibody titers in the ferrets and protected them against intratracheal wild-type pH1N1 virus challenge: pH1N1 virus replication in the upper respiratory tract and lungs was reduced and no disease signs or severe broncho-interstitial pneumonia were observed in any of the vaccinated ferrets. These data together with the relatively efficient production process emphasize the potential of the LAIV concept for pandemic preparedness. (C) 2011 Elsevier Ltd. All rights reserved.

Antibody levels in 41 Indian girls were measured 6 years after measles-mumps-rubella (MMR) vaccination. Rates of seropositivity were 88% (measles antibodies), 95% (mumps antibodies), and 100% (rubella antibodies). The MMR vaccine induces long-term immunity in a majority of vaccinees; however, due to the observation of some seronegative vaccinees, the policy of administering a second dose of the MMR vaccine seems appropriate.

Dear Editor, Horizontal transmission has been rarely reported with of many live attenuated vaccines. Different mumps vaccines have shown rarely such transmission.1–5 A study in US reported evidence of the transmission of rubella vaccine virus from vaccinees to two susceptible contacts.6 With live varicella vaccines, there are at least three reports. The brother of a 3-y-old vaccinated girl developed fever and a rash; horizontal transmission of vaccine virus was later confirmed.7 A pregnant mother contracted the vaccine virus after her 12-mo-old boy received varicella vaccine.8 Horizontal transmission was reported in 15 (17%) susceptible healthy siblings after varicella vaccination of 156 children with leukemia.9 The package insert of live varicella vaccine (Varivax, Merck) states that “Post-marketing experience suggests that transmission of vaccine virus may occur rarely between healthy vaccinees who develop a varicella-like rash and healthy susceptible contacts. Transmission of vaccine virus from vaccinees who do not develop a varicella-like rash has also been reported.”10 There are two reports with rotavirus vaccines. A randomized, double-blind study on human rotavirus vaccine (Rotarix™, Glaxo) in 100 pairs of healthy twins found that the transmission rate among placebo recipients was 18.8%.11 In another case, rotavirus vaccine (RotaTeq, Merck) transmission was reported from a vaccinated infant to an older, unvaccinated sibling, resulting in symptomatic rotavirus gastroenteritis.12 A study on live attenuated influenza vaccine (FluMist, MedImmune) in a Finnish day care showed that one child in the placebo group had transiently detectable vaccine virus, indicating transmission from a vaccinated child; the child remained asymptomatic.13 Despite these reports, these live vaccines are used in millions of doses across the world. Clearly, the benefit of vaccination outweighs the very low risk of vaccine virus transmission.

To address the claim that the Leningrad–Zagreb (L-Z) mumps vaccine strain is causally associated with aseptic meningitis, a prospective, post-marketing safety study was conducted with a measles-mumps-rubella vaccine (MMR) (TRESIVAC°; Serum Institute of India Ltd., Pune, India), which uses the L-Z strain as its mumps component in Egypt. In all, 453 119 children (65 423 children aged 16–24 months and 329 211 children aged 5–7 years) received MMR. The control groups which, as a result of local health regulations, were slightly younger than vaccinees, comprised 12 253 and 46 232 children, respectively. Using questionnaires, the parents recorded solicited local, systemic and neurological adverse events for up to 42 days post-vaccination. All data were analysed externally on an intention-to-treat basis by individuals not participating in the study. Local and/or systemic reactions were reported in a small percentage of participants, with pain, fever and parotitis being the most common signs among vaccinees in both age groups. No case of aseptic meningitis, encephalitis, anaphylaxis or convulsions was observed in any participant. Thus, in this series of more than 450 000 Egyptian children, the L-Z mumps vaccine strain in this vaccine did not cause aseptic meningitis. The vaccine is considerably cheaper than Western competitors and a valid alternative to other MMR vaccines.