Molecular size distribution in pentavalent (A, C, Y, W, X) meningococcal polysaccharide conjugate vaccine by HPSEC-UV-MALS-RI method- a conceivable stability indicating parameter.

Molecular size distribution (MSD) of polysaccharides serves as a key parameter that directly correlates to the immunogenicity of vaccine. MSD at meningococcal polysaccharide (A, C, Y and W) or conjugate bulk level is well established under detailed pharmacopeial and WHO guidelines. We report here, a newly developed method for determination of molecular size distribution of pentavalent Meningococcal conjugate vaccine comprising of A, C, Y, W and X (MenFive). Although serogroup specific molecular size could not be estimated here; lot to lot consistency monitoring, molecular aggregates distribution in final lot, are key takeaways of this method. Determination of MSD in pentavalent fill finished product was quite challenging. Various columns/detectors combination, buffers, physico-chemical conditions (temperature, 2-8 °C, 25 °C, 40 °C and 60 °C; flow rate, 0.3 mL to 0.8 mL), liquid/lyophilized formulations, were explored. Polymer-based packed columns were explored for estimation for MSD by aqueous size exclusion chromatography, using combinations of- Shodex OHPAK SB 807 HQ, Shodex OHPAK SB 806 HQ, G6000 PWXL, coupled with guard Shodex OHPAK SB-G-6B. MenFive showed heterogenous distribution of molecules ranging from 200 to 19000 kDa, indicating its complex nature. However, 1000-8000 kDa was dominant range, comprising of ≥ 50 % distribution of molecules, in both liquid as well as lyophilized formulations, with average molecular weight around 6000-6500 kDa. The molar mass distribution after slicing would provide an insight to the conformation of molecules through its presentation as HMW, LMW, aggregates and subsequently, the presence of dominant population of molecules of a particular molecular weight and its total contribution in the sample.

Safety and efficacy of malaria vaccine candidate R21/Matrix-M in African children: a multicentre, double-blind, randomised, phase 3 trial.

BACKGROUND: Recently, we found that a new malaria vaccine, R21/Matrix-M, had over 75% efficacy against clinical malaria with seasonal administration in a phase 2b trial in Burkina Faso. Here, we report on safety and efficacy of the vaccine in a phase 3 trial enrolling over 4800 children across four countries followed for up to 18 months at seasonal sites and 12 months at standard sites. METHODS: We did a double-blind, randomised, phase 3 trial of the R21/Matrix-M malaria vaccine across five sites in four African countries with differing malaria transmission intensities and seasonality. Children (aged 5-36 months) were enrolled and randomly assigned (2:1) to receive 5 µg R21 plus 50 µg Matrix-M or a control vaccine (licensed rabies vaccine [Abhayrab]). Participants, their families, investigators, laboratory teams, and the local study team were masked to treatment. Vaccines were administered as three doses, 4 weeks apart, with a booster administered 12 months after the third dose. Half of the children were recruited at two sites with seasonal malaria transmission and the remainder at standard sites with perennial malaria transmission using age-based immunisation. The primary objective was protective efficacy of R21/Matrix-M from 14 days after third vaccination to 12 months after completion of the primary series at seasonal and standard sites separately as co-primary endpoints. Vaccine efficacy against multiple malaria episodes and severe malaria, as well as safety and immunogenicity, were also assessed. This trial is registered on ClinicalTrials.gov, NCT04704830, and is ongoing. FINDINGS: From April 26, 2021, to Jan 12, 2022, 5477 children consented to be screened, of whom 1705 were randomly assigned to control vaccine and 3434 to R21/Matrix-M; 4878 participants received the first dose of vaccine. 3103 participants in the R21/Matrix-M group and 1541 participants in the control group were included in the modified per-protocol analysis (2412 [51·9%] male and 2232 [48·1%] female). R21/Matrix-M vaccine was well tolerated, with injection site pain (301 [18·6%] of 1615 participants) and fever (754 [46·7%] of 1615 participants) as the most frequent adverse events. Number of adverse events of special interest and serious adverse events did not significantly differ between the vaccine groups. There were no treatment-related deaths. 12-month vaccine efficacy was 75% (95% CI 71-79; p<0·0001) at the seasonal sites and 68% (61-74; p<0·0001) at the standard sites for time to first clinical malaria episode. Similarly, vaccine efficacy against multiple clinical malaria episodes was 75% (71-78; p<0·0001) at the seasonal sites and 67% (59-73; p<0·0001) at standard sites. A modest reduction in vaccine efficacy was observed over the first 12 months of follow-up, of similar size at seasonal and standard sites. A rate reduction of 868 (95% CI 762-974) cases per 1000 children-years at seasonal sites and 296 (231-362) at standard sites occurred over 12 months. Vaccine-induced antibodies against the conserved central Asn-Ala-Asn-Pro (NANP) repeat sequence of circumsporozoite protein correlated with vaccine efficacy. Higher NANP-specific antibody titres were observed in the 5-17 month age group compared with 18-36 month age group, and the younger age group had the highest 12-month vaccine efficacy on time to first clinical malaria episode at seasonal (79% [95% CI 73-84]; p<0·001) and standard (75% [65-83]; p<0·001) sites. INTERPRETATION: R21/Matrix-M was well tolerated and offered high efficacy against clinical malaria in African children. This low-cost, high-efficacy vaccine is already licensed by several African countries, and recently received a WHO policy recommendation and prequalification, offering large-scale supply to help reduce the great burden of malaria in sub-Saharan Africa. FUNDING: The Serum Institute of India, the Wellcome Trust, the UK National Institute for Health Research Oxford Biomedical Research Centre, and Open Philanthropy.

A phase III randomized-controlled study of safety and immunogenicity of DTwP-HepB-IPV-Hib vaccine (HEXASIIL®) in infants.

A fully liquid hexavalent containing Diphtheria (D), Tetanus (T) toxoids, whole cell Pertussis (wP), Hepatitis B (Hep B), type 1, 2, 3 of inactivated poliovirus (IPV) and Haemophilus influenzae type b (Hib) conjugate vaccine (DTwP-HepB-IPV-Hib vaccine, HEXASIIL®) was tested for lot-to-lot consistency and non-inferiority against licensed DTwP-HepB-Hib + IPV in an open label, randomized Phase II/III study. In Phase III part, healthy infants received DTwP-HepB-IPV-Hib or DTwP-HepB-Hib + IPV vaccines at 6, 10 and 14 weeks of age. Blood samples were collected prior to the first dose and 28 days, post dose 3. Non inferiority versus DTwP-HepB-Hib + IPV was demonstrated with 95% CIs for the treatment difference for seroprotection/seroconversion rates. For DTwP-HepB-IPV-Hib lots, limits of 95% CI for post-vaccination geometric mean concentration ratios were within equivalence limits (0.5 and 2). Vaccine was well-tolerated and no safety concerns observed.Clinical Trial Registration - CTRI/2019/11/022052.

Immunogenicity and safety of a new quadrivalent HPV vaccine in girls and boys aged 9-14 years versus an established quadrivalent HPV vaccine in women aged 15-26 years in India: a randomised, active-controlled, multicentre, phase 2/3 trial.

BACKGROUND: To meet global cervical cancer elimination efforts, a wider range of affordable and accessible vaccines against human papillomavirus (HPV) are needed. We aimed to evaluate the immunogenicity and safety of a quadrivalent HPV vaccine (targeting HPV types 6, 11, 16, and 18), developed and manufactured by the Serum Institute of India (SIIPL). Here we report outcomes in the 9-14 years cohort. METHODS: This randomised, active-controlled, phase 2/3 trial was conducted at 12 tertiary care hospitals across India. Healthy participants aged 9-14 years or 15-26 years with no history of HPV vaccination were eligible for enrolment. Female participants were randomly assigned (1:1) with an interactive web response system, by use of a central computer-generated schedule and block randomisation (block sizes of 2, 4, 6, and 8), to receive the SIIPL quadrivalent HPV vaccine (Cervavac; SIIPL, Pune, India) or the comparator quadrivalent HPV vaccine (Gardasil; Merck Sharp & Dohme, Harleem, the Netherlands). Participants, investigators, laboratory technicians, and sponsors were masked to treatment allocation of female participants. Male participants were given the SIIPL quadrivalent HPV vaccine in an open-label manner. Study vaccines were administered intramuscularly with a two-dose schedule (at day 0 and 6 months) in the cohort aged 9-14 years, and with a three-dose schedule (at day 0, month 2, and month 6) in the cohort aged 15-26-years. Immunogenicity was assessed 30 days after the last dose by use of multiplexed ELISA. The primary outcome was the non-inferiority of immune response in terms of the geometric mean titre (GMT) of antibodies against HPV types 6, 11, 16, and 18 generated by the SIIPL quadrivalent HPV vaccine in girls and boys (aged 9-14 years) compared with the GMT generated by the comparator quadrivalent HPV vaccine in women aged 15-26 years at month 7 in the modified per-protocol population (ie, all participants who received all doses of study vaccines per assigned treatment group and had both day 0 and 1-month immunogenicity measurements after the last dose following protocol-defined window periods with no major protocol deviations). Non-inferiority was established if the lower bound of the 98·75% CI of the GMT ratio was 0·67 or higher. The co-primary outcome of occurrence of solicited adverse events (within 7 days of each dose) and unsolicited adverse events (up to 30 days after the last dose) was assessed in all participants who were enrolled and received at least one dose of study vaccine. The trial is registered with the Clinical Trials Registry - India (CTRI/2018/06/014601), and long-term follow-up is ongoing. FINDINGS: Between Sept 20, 2018, and Feb 9, 2021, 2341 individuals were screened, of whom 2307 eligible individuals were enrolled and vaccinated: 1107 (738 girls and 369 boys) in the cohort aged 9-14 years and 1200 (819 women and 381 men) in the cohort aged 15-26 years. No race or ethnicity data were collected. 350 girls and 349 boys in the SIIPL quadrivalent HPV vaccine group and 338 women in the comparator vaccine group were included in the modified per-protocol population for the primary endpoint analysis. The median follow-up for the analyses was 221 days (IQR 215-231) for girls and 222 days (217-230) for boys in the SIIPL quadrivalent HPV vaccine group, 223 days (216-232) for girls in the comparator vaccine group, and 222 days (216-230) for women in the comparator vaccine group. GMT ratios were non-inferior in girls and boys receiving the SIIPL quadrivalent HPV vaccine compared with women receiving the comparator vaccine: GMT ratios for girls were 1·97 (98·75% CI 1·67-2·32) for HPV type 6, 1·63 (1·38-1·91) for HPV type 11, 1·90 (1·60-2·25) for HPV type 16, and 2·16 (1·79-2·61) for HPV type 18. For boys the GMT ratios were 1·86 (1·57-2·21) for HPV type 6, 1·46 (1·23-1·73) for HPV type 11, 1·62 (1·36-1·94) for HPV type 16, and 1·80 (1·48-2·18) for HPV type 18. The safety population comprised all 1107 participants (369 girls and 369 boys in the SIIPL quadrivalent HPV vaccine group, and 369 girls in the comparator group). Solicited adverse events occurred in 176 (48%) of 369 girls and 124 (34%) of 369 boys in the SIIPL vaccine group and 179 (49%) of 369 girls in the comparator vaccine group. No grade 3-4 solicited adverse events occurred within 7 days of each dose. Unsolicited adverse events occurred in 143 (39%) girls and 147 (40%) boys in the SIIPL vaccine group, and 143 (39%) girls in the comparator vaccine group. The most common grade 3 unsolicited adverse event was dengue fever, in one (<1%) girl in the SIIPL vaccine group and three (1%) girls in the comparator group. There were no grade 4 or 5 adverse events. Serious adverse events occurred in three (1%) girls and three (1%) boys in the SIIPL vaccine group, and five (1%) girls in the comparator vaccine group. No vaccine-related serious adverse events were reported. There were no treatment-related deaths. INTERPRETATION: We observed a non-inferior immune response with the SIIPL quadrivalent HPV vaccine in girls and boys aged 9-14 years and an acceptable safety profile compared with the comparator vaccine. These findings support extrapolation of efficacy from the comparator vaccine to the SIIPL quadrivalent HPV vaccine in the younger population. The availability of the SIIPL quadrivalent HPV vaccine could help meet the global demand for HPV vaccines, and boost coverage for both girls and boys globally. FUNDING: Biotechnology Industry Research Assistance Council, Department of Biotechnology (DBT), Government of India, and Serum Institute of India.

Safety and immunogenicity of SIIPL Tdap, a new tetanus toxoid, reduced diphtheria toxoid and acellular pertussis vaccine, in healthy subjects 4-65 years of age: A Phase II/III randomized, observer-blinded, active controlled, multicenter clinical study in Germany.

BACKGROUND: This study assessed the safety and immunogenicity of a new booster vaccine against tetanus, diphtheria, and pertussis manufactured by Serum Institute of India Pvt. Ltd (SIIPL Tdap). METHODS: The Phase II/III trial was randomized (2:1), observer blinded and active controlled. Healthy subjects aged 4-65 years received a single dose of either SIIPL Tdap or comparator Tdap vaccine (Boostrix®, GlaxoSmithKline, Belgium), and were followed-up for 30 days. Blood samples for safety and immunogenicity assessments were collected pre-vaccination and on day 30 post-vaccination. The study assessed safety and reactogenicity of SIIPL Tdap compared to the comparator Tdap as well as the co-primary immunogenicity outcomes: (i) seroprotection rates against diphtheria toxoid (DT) and tetanus toxoid (TT) and (ii) the booster response rates against pertussis toxoid (PT), filamentous hemagglutinin (FHA) and pertactin (PRN) 30 days post-vaccination in all study subjects. A margin of -10 % was used for non-inferiority testing. Secondary outcomes included the booster response rates against DT and TT, seropositivity rates against pertussis antigens, and antibody geometric mean concentrations (GMCs) for all vaccine components. RESULTS: At Day 30 post-vaccination, SIIPL Tdap was assessed as non-inferior to the comparator Tdap in terms of: i) seroprotection rates against DT (94.4 % vs. 94.9 %) and TT (99.9 % vs. 100 %) and ii) pertussis booster response rates (93.8 % vs. 88.4 % anti-PT, 89.7 % vs. 90.9 % anti-FHA and 86.3 % vs. 84.4 % anti-PRN), for SIIPL Tdap versus comparator Tdap, respectively. GMCs for anti-PT and anti-PRN were higher in subjects vaccinated with SIIPL Tdap compared to comparator Tdap. All other secondary outcomes were comparable. The overall frequency of local and systemic solicited AEs was comparable; no treatment related SAEs were reported. CONCLUSIONS: Booster vaccination with SIIPL Tdap was non-inferior to comparator Tdap with respect to the immunogenicity of the vaccine components and was equally well tolerated. EudraCT number: 2019-002706-46.

Large-Scale Purification and Characterization of Recombinant Receptor-Binding Domain (RBD) of SARS-CoV-2 Spike Protein Expressed in Yeast.

SARS-CoV-2 spike protein is an essential component of numerous protein-based vaccines for COVID-19. The receptor-binding domain of this spike protein is a promising antigen with ease of expression in microbial hosts and scalability at comparatively low production costs. This study describes the production, purification, and characterization of RBD of SARS-CoV-2 protein, which is currently in clinical trials, from a commercialization perspective. The protein was expressed in Pichia pastoris in a large-scale bioreactor of 1200 L capacity. Protein capture and purification are conducted through mixed-mode chromatography followed by hydrophobic interaction chromatography. This two-step purification process produced RBD with an overall productivity of ~21 mg/L at >99% purity. The protein's primary, secondary, and tertiary structures were also verified using LCMS-based peptide mapping, circular dichroism, and fluorescence spectroscopy, respectively. The glycoprotein was further characterized for quality attributes such as glycosylation, molecular weight, purity, di-sulfide bonding, etc. Through structural analysis, it was confirmed that the product maintained a consistent quality across different batches during the large-scale production process. The binding capacity of RBD of spike protein was also assessed using human angiotensin-converting enzyme 2 receptor. A low binding constant range of KD values, ranging between 3.63 × 10-8 to 6.67 × 10-8, demonstrated a high affinity for the ACE2 receptor, revealing this protein as a promising candidate to prevent the entry of COVID-19 virus.

Innovative method for rapid detection of falsified COVID-19 vaccines through unopened vials using handheld Spatially Offset Raman Spectroscopy (SORS).

Preventing, detecting, and responding to substandard and falsified vaccines is of critical importance for ensuring the safety, efficacy, and public trust in vaccines. This is of heightened importance in context of public health crisis, such as the COVID-19 pandemic, in which extreme world-wide shortages of vaccines provided a fertile ground for exploitation by falsifiers. Here, a proof-of-concept study explored the feasibility of using a handheld Spatially Offset Raman Spectroscopy (SORS) device to authenticate COVID-19 vaccines through rapid analysis of unopened vaccine vials. The results show that SORS can verify the chemical identity of dominant excipients non-invasively through vaccine vial walls. The ability of SORS to identify potentially falsified COVID-19 vaccines was demonstrated by measurement of surrogates for falsified vaccines contained in vaccine vials. In all cases studied, the SORS technique was able to differentiate between surrogate samples from the genuine COVISHIELD™ vaccine. The genuine vaccines tested included samples from six batches across two manufacturing sites to account for any potential variations between batches or manufacturing sites. Batch and manufacturing site variations were insignificant. In conjunction with existing security features, for example on labels and packaging, SORS provided an intrinsic molecular fingerprint of the dominant excipients of the vaccines. The technique could be extended to other COVID-19 and non-COVID-19 vaccines, as well as other liquid medicines. As handheld and portable SORS devices are commercially available and widely used for other purposes, such as airport security, they are rapidly deployable non-invasive screening tools for vaccine authentication.

Method development and validation of unbound saccharide content (serogroup A, C, Y, W, X) in novel pentavalent meningococcal polysaccharide conjugate vaccine with two different carrier proteins.

Exclusive DOC-HCl formulations were developed for free polysaccharide content estimation in Meningococcal serogroup A, C, Y, W and X from pentavalent meningococcal vaccine (A, C, Y, W, X). The DOC precipitation method reported herein stands as an alternative to the ultra-filtration method for free polysaccharide estimation. DOC content was optimized for all the serogroups at a single concentration, where as effective acid concentration was altered as per serogroup. Briefly, two DOC-HCl formulations were developed for intended purpose, one for TT conjugated serogroups Men A & Men X where as other for CRM conjugated serogroups Men C, Men Y and Men W with effective HCl concentration of 23 mM and 193 mM for precipitation of Protein-DOC complex respectively. Furthermore, an exclusive buffer/DOC-HCl formulation for estimation of Men X free polysaccharide in fill finished product was developed. Accuracy of the method was proven at 12.5 %, 25 %, 50 % and 100 % of test specification where recoveries were found in the range of 70-130 %. In case of repeatability, intra assay variation ranged from 2 % to 7 % whereas inter assay variation was noted to be 2-14 %. Specificity studied revealed no interference of assay components such as sample excipients, DOC, acids. Critical quality and stability-indicating characteristics were measured. Monovalent polysaccharide standards of Men A, C, Y, W and X were developed and assigned the unitage concentration 1.01, 1.10, 1.09, 1.08 and 1.00 mg/mL respectively. Linearity curve was optimized from 0.17 to 27 µg/mL for Men A and C whereas from 0.33 to 27 µg/mL for Men Y and W considering free polysaccharide content estimation. The study suggests that DOC-HCl method meets all the criteria for free polysaccharide estimation in multivalent vaccines with additional advantages of high throughput and sized independent separation hence can be used for quality control testing.

Development and validation of capillary electrophoresis sodium dodecyl sulfate (CE-SDS) method for purity analysis of pertussis toxin, filamentous haemagglutinin and pertactin antigens.

We report here the development and validation of CE-SDS method for purity analysis of Acellular Pertussis vaccine components viz. purified Pertussis toxin (PTx), purified Filamentous haemagglutinin (FHA), and Pertactinantigen (PRN). The method was found to be specific and showed excellent linearity at a concentration range of 15.62 µg/mL-1000 µg/mL for purified PTx, 31.25 µg/mL-1000 µg/mL for purified FHA, and 3.9 µg/mL-1000 µg/mL for PRN antigen. Method reported limit of quantification (LOQ) 31.25 µg/mL, 62.5 µg/mL, and 7.8 µg/mL for purified PTx, FHA, and PRN respectively. Method precision (repeatability and intermediate precision) for purity and molecular weight determination in product matrix was below 10% for all three proteins. Method comparability studies were performed with SDS-PAGE. CE-SDS demonstrated corroborating results with SDS-PAGE for the estimation of purity and molecular weight analysis. However, CE-SDS method exhibited better resolution capabilities for resolving all the sub-unit peaks of PTx and isoforms of purified FHA. CE-SDS method also demonstrated stability indicating potential and thus fits its intended purpose as an effective analytical tool for quality control of acellular pertussis-based vaccines.

Stability of lyophilized Meningococcal A conjugate vaccine, (MenAfriVac™) at elevated temperatures to support controlled temperature chain (CTC) claim.

Meningococcal A Conjugate Vaccine (MenAfriVac) is the world's first Monovalent Conjugate Vaccine against Neisseria Meningitidis serogroup A which has obtained Controlled Temperature Chain (CTC) label claim of "stable upto 40°C for 4 days prior to reconstitution" developed by Serum Institute of India Pvt. Ltd. Pune, India and the vaccine was granted permission from World health Organization. This paper elucidates and talks about the layout of various studies performed to characterize the product to declare as CTC at the time when the knowledge and mechanism to describe CTC was not fully known which in term helped to design the CTC guidelines. Product stability was assessed using clinical, consistency and regular lots released by NRA. The critical stability indicating parameters like free polysaccharide, molecular size distribution along with Potency and safety tests were carried out to support the product stability making sure it also qualifies for Vaccine Vial Monitor label claim of VVM30. An additional in use stability (reconstitution) was also performed. All studies indicated that the product remains stable at real time as well as elevated temperatures and well within the specifications approved by NRA and formed the strong basis for CTC claim which is now recommended by WHO.

Multiplexed bead-based assay for the simultaneous quantification of human serum IgG antibodies to tetanus, diphtheria, pertussis toxin, filamentous hemagglutinin, and pertactin.

Background: Luminex bead-based assays offer multiplexing to test antibodies against multiple antigens simultaneously; however, this requires validation using internationally certified reference standards. Therefore, there is an urgent need to characterize existing reference standards for the standardization of multiplex immunoassays (MIAs). Here, we report the development and validation of an MIA for the simultaneous estimation of levels of human serum immunoglobulin G (IgG) antibodies for pertussis toxin (PT), filamentous hemagglutinin (FHA), pertactin (PRN), diphtheria toxoid (DT), and tetanus toxoid (TT). Methods: The MIA was assessed using a panel of human serum samples and WHO reference standards. The WHO reference standards were also studied for suitability in the MIA. Purified antigens (PT, FHA, PRN, DT, and TT) were coupled to the spectrally unique magnetic carboxylated microspheres. The method was validated in accordance with the United States Food and Drug Administration (US FDA), European Medicines Agency (EMA), and the International Committee of Harmonization Multidisciplinary (ICH M10) guidelines, and parameters such as precision, accuracy, dilutional linearity, assay range, robustness, and stability were assessed. Method agreements with commercially available IgG enzyme-linked immunosorbent assay (ELISA) assays were also evaluated. In addition, the study assessed the level of correlation between the IgG levels estimated by the MIA and the cell-based neutralizing antibody assays for PT and DT. Results: We identified that an equimix of WHO international standards (i.e., 06/142, 10/262, and TE-3) afforded the best dynamic range for all the antigens in the MIA. For all five antigens, we observed that the back-fitted recoveries using the four-parameter logistic (4-PL) regression fits ranged between 80% and 120% for all calibration levels, and the percentage coefficient of variation (% CV) was < 20%. In addition, the difference in mean fluorescence intensity (MFI) between the monoplex and multiplex format was < 10% for each antigen, indicating no crosstalk among the beads. The MIA also showed good agreement with conventional and commercially available assays, and a positive correlation (> 0.75) with toxin neutralization assays for PT and DT was observed. Conclusion: The MIA that was calibrated in accordance with WHO reference standards demonstrated increased sensitivity, reproducibility, and high throughput capabilities, allowing for the design of robust studies that evaluate both natural and vaccine-induced immunity.

A Phase I study to evaluate safety and tolerability of DTaP-IPV + Hib vaccine in healthy adult volunteers in India.

Background: To assess safety and tolerability of a diphtheria and tetanus toxoid, acellular pertussis, inactivated poliovirus and Haemophilus influenza type B conjugate adsorbed vaccine (DTaP-IPV + Hib), manufactured by Serum Institute of India Pvt. Ltd. (SIIPL)'s, the current first-in-human Phase 1 study was conducted in healthy adults. Methods: Vaccine was administered as a single 0.5 mL dose intramuscularly into deltoid muscle of 24 healthy adults aged 18-45 years, who were then followed prospectively for one month for safety outcomes. Results: All 24 participants completed the study in compliance with protocol. Four solicited adverse events were reported in three participants during the study; all adverse events were mild and recovered completely. No deaths, unsolicited adverse events, or serious adverse events were reported. Conclusion: SIIPL DTaP-IPV + Hib vaccine was well tolerated and safe in study subjects. Further clinical development will be conducted to assess safety and immunogenicity in young children, the target population.Clinical Trial Registration: CTRI/2017/07/009034.

A phase-I, open label clinical trial to assess the safety & tolerability of qHPV vaccine manufactured by Serum Institute of India Pvt. Ltd. in adults.

Background: This first in human study was designed as an open label clinical trial to assess safety and tolerability of Serum Institute of India Pvt. Ltd. (SIIPL) quadrivalent HPV (qHPV) vaccine. Methods: A total of 48 healthy male and female (24 each) adult volunteers were administered a 0.5 ml single dose of SIIPL qHPV vaccine intramuscularly, and were followed for one month for safety outcomes viz., immediate, solicited, unsolicited and serious adverse events. Results: 47 subjects completed the study in compliance with protocol. One subject had pain immediately after immunization which was recovered without treatment. None of the participants experienced any other local or systemic solicited AEs and serious AE. Conclusion: qHPV vaccine manufactured by SIIPL was found to be safe and well tolerable in adults. Further clinical development should continue to assess safety and immunogenicity, in the target population following recommended 2 and 3-dose schedule.Clinical Trial Registration - CTRI/2017/02/007785.

Safety and immunogenicity of an indigenously developed tetanus toxoid, diphtheria toxoid, and acellular pertussis vaccine (Tdap) in adults, adolescents, and children in India.

BACKGROUND: This study assessed safety and immunogenicity of Serum Institute of India Pvt Ltd (SIIPL)'s tetanus toxoid (TT), diphtheria toxoid (DT), and acellular pertussis booster vaccine (Tdap). RESEARCH DESIGN AND METHODS: In this Phase II/III, multicenter, randomized, active-controlled, open-label study, 1500 healthy individuals, aged 4-65 years, were randomized to receive a single dose of SIIPL Tdap or comparator Tdap vaccine (Boostrix®; GlaxoSmithKlines, India). Adverse events (AEs) during initial 30 minutes, 7-day, 30-day post-vaccination were assessed. Blood samples were taken before and 30 days post-vaccination for immunogenicity assessment. RESULTS: No significant differences in incidence of local and systemic solicited AEs were observed between the two groups; no vaccine-related serious AEs were reported. SIIPL Tdap was non-inferior to comparator Tdap in achieving booster responses to TT and DT in 75.2% and 70.8% of the participants, respectively, and to pertussis toxoid (PT), pertactin (PRN), and filamentous hemagglutinin (FHA) in 94.3%, 92.6%, and 95.0% of the participants, respectively. Anti-PT, anti-PRN, and anti-FHA antibody geometric mean titers in both the groups, were significantly higher post-vaccination compared to pre-vaccination. CONCLUSIONS: Booster vaccination with SIIPL Tdap was non-inferior to comparator Tdap with respect to immunogenicity against tetanus, diphtheria, and pertussis and was well tolerated.

A novel high throughput plate-based method for 2-PE quantification in novel multidose vaccines (R21 malaria, Covishield and Covovax) and combination vaccines (Hexavalent).

Multidose presentation of vaccines is the most preferred choice, for mass immunization particularly during pandemics. WHO also recommends multidose containers of fill finished vaccines for programmatic suitability and global immunizations programmes. However, multidose vaccine presentations requires inclusion of preservatives to prevent contaminations. 2-Phenoxy ethanol (2-PE) is one such preservative which is being used in numerous cosmetics and many vaccines recently. Estimation of 2-PE content in multidose vials is a crucial quality control parameter to ensure in use stability of the vaccines. Presently available conventional methods, have their own limitation in terms of being time consuming, requiring sample extraction, large sample volume requirement etc. Therefore, a robust, simple, high-throughput method with a low turnaround time was required, which can quantitate 2-PE content in the conventional combination vaccines as well as new generation complex VLP based vaccines. In order to address this issue, a novel absorbance-based method has been developed. This novel method specifically detects 2-PE content in Matrix M1 adjuvanted R21 malaria vaccine, nano particle and viral vector based covid vaccines and combination vaccines like Hexavalent vaccine. The method has been validated for parameters such as linearity, accuracy and precision. Importantly, this method works even in presence of high amounts of proteins and residual DNA. Considering the advantages associated with method under study, this method can be used as an important in process or release quality parameter to estimate the 2-PE content in various vaccines containing 2-PE in multidose presentations.

Development and validation of a spectrophotometric method for quantification of residual cyclodextrin (DIMEB; Heptakis) in pertussis antigens.

Methylated derivatives of cyclodextrins such as DIMEB (2,6-di-O-methyl)-ß-cyclodextrin or Heptakis is commonly used as culture medium modifier in manufacturing of pertussis antigens for promoting the growth of bacteria. We report here development and validation of a spectrophotometric method for estimation of DIMEB in different product matrices of pertussis vaccine antigens i.e. Filamentous haemagglutinin (FHA), Pertactin (PRN) and Pertussis toxin (PT). The detection is based on characteristic reaction of hydrolyzed sugars derivatives from DIMEB i.e., furfural derivatives with anthrone reagent to form colored complexes which could be quantified at 625 nm. Method showed excellent linearity with correlation coefficient (R2) > 0.995 over the concentration of 5.0-80.0 µg. LOD and LOQ of 1.47 µg and 4.46 µg respectively was reported. The overall precision (repeatability and intermediate precision) showed % RSD for DIMEB content <10.0% for all the matrices. % Recoveries for DIMEB after three different spike levels (low, middle and high) were within 90%-113%. The method was successfully applied for determination of residual DIMEB in different product matrices of FHA, PRN and PT protein antigens. This can be used to monitor residual DIMEB levels during manufacturing of acellular pertussis antigens.

Neurovirulence, viscerotropism and immunogenicity of live attenuated yellow fever 17D vaccine virus in non-human primates.

Yellow fever vaccine associated neurovirulence and viscerotropism have been reported by various countries. In this study, the neurovirulence, viscerotropism and immunogenicity of yellow fever vaccine seed lots (master and working) and final product manufactured at Serum Institute of India (SII) were evaluated in cynomolgus monkeys. WHO reference virus 168-73 and Stamaril™ as a control vaccine was used for comparison. Neurovirulence and viscerotropism scores of the seed lots and final product were lower than Stamaril™. The SII seed virus and vaccine complies to the WHO requirement for neurovirulence, viscerotropism and immunogenicity, when tested in comparison to WHO reference seed virus 168/73. All challenged animals showed 100 % seroconversion as early as day 14 and neutralizing antibody titers were sustainable at day 30 in all animals.

A phase I, open label, clinical study to assess the safety and immunogenicity of indigenously developed liquid (DTwP-HepB-IPV-Hib) hexavalent combination vaccine in healthy toddlers aged 16-24 months.

This first in human study was designed as an open label clinical trial to assess the safety and immunogenicity of SIIPL DTwP-HepB-IPV-Hib (Hexavalent) combination vaccine in healthy toddlers, aged 16-24 months. A total of 24 healthy toddlers were administered a 0.5 ml single dose of SIIPL DTwP-HepB-IPV-Hib vaccine intramuscularly, and followed for 28 days for safety outcomes viz. immediate, solicited, unsolicited and serious adverse events. Blood samples were collected immediately prior to and 28 days after vaccination to assess the immunogenicity. Twenty four completed the study in compliance with the study protocol. None of the participants experienced any immediate or any serious adverse event. In terms of the frequency and intensity, the adverse events were comparable to DTwP-based combination vaccines. The vaccine elicited a strong booster response as demonstrated by a large increase in antibodies against all vaccine antigens. One month post booster vaccination seroprotection for diphtheria, tetanus, Hepatitis B, Haemophilus influenzae type b and polio virus type 1 and 3 was 100%. The percentage sero-response for pertussis was 75%. Four-fold increase in antibody concentration for pertussis was achieved in 87.5% subjects. Indigenously developed DTwP-HepB-IPV-Hib vaccine by Serum Institute of India Pvt. Ltd. was found to be safe, well tolerated and showed a robust immune response in toddlers. It was concluded that this vaccine should be assessed in the next phases of clinical development in the target population.Clinical Trial Registration - CTRI/2018/10/015875.

Characterization of Bordetella pertussis Strains Isolated from India.

Despite high level vaccination and the availability of two different types of vaccines, whole cell (wP) and acellular vaccines (aP), the resurgence of pertussis has been reported in many countries. Antigenic variation within circulating and vaccine strains is the most documented reason reported for the resurgence of pertussis. Research on genetic divergence among circulating and vaccine strains has largely been reported in countries using aP vaccines. There are inadequate data available for antigenic variation in B. pertussis from wP-using countries. India has used wP for more than 40 years in their primary immunization program. The present study reports five clinical isolates of B. pertussis from samples of pediatric patients with pertussis symptoms observed in India. Genotypic and phenotypic characterization of clinical isolates were performed by serotyping, genotyping, whole genome analyses and comparative genomics. All clinical isolates showed serotype 1, 2 and 3 based on the presence of fimbriae 2 and 3. Genotyping showed genetic similarities in allele types for five aP genes within vaccine strains and clinical isolates reported from India. The presence of the ptxP3 genotype was observed in two out of five clinical isolates. Whole-genome sequencing was performed for clinical isolates using the hybrid strategy of combining Illumina (short reads) and oxford nanopore (long reads) sequencing strategies. Clinical isolates (n = 5) and vaccine strains (n = 7) genomes of B. pertussis from India were compared with 744 B. pertussis closed genomes available in the public databases. The phylogenomic comparison of B. pertussis genomes reported from India will be advantageous in better understanding pertussis resurgence reported globally with respect to pathogen adaptation.

Antiviral Activity of Rosmarinic Acid Against Four Serotypes of Dengue Virus.

The present study was undertaken to evaluate the putative antiviral activity of Rosmarinic acid (RA) against four serotypes of dengue virus (DENV). Our previous in silico binding analysis revealed that RA binds strongly to the envelope domain III (EDIII) protein of all four DENV serotypes. We employed an in vitro Biolayer Interferometry-based OCTET™ platform to study the binding interaction of RA with EDIII protein of the four DENV serotypes. Additionally, a functional plaque assay was developed to investigate the potential inhibition of infection of the four DENV serotypes. Using OCTET™, the binding interaction of RA to DENV-EDIII protein of the four DENV serotypes demonstrates interaction which can be arranged in the following order: EDIII-DENV1 (Koff value of 1.05 s-1) > EDIII-DENV2 (Koff value of 5.63 × 10-01 s-1) > EDIII-DENV3 (Koff value of 4.63 × 10-02 s-1) > EDIII-DENV4 (Koff value of 3.53 × 10-02 s-1). Subsequently, the inhibiting ability of RA using plaque assay confirmed reduction in the number of plaques for all four serotypes, indicating the ability of RA not only to bind, but also to inhibit the infection of four serotypes in cell culture, while being non-toxic at the concentrations used in the study. However, the effect of RA was variable on different serotypes, demonstrating highest effect on DENV1 (EC50 = 13.73 µg/mL, SI ≥ 728) followed by DENV2 (EC50 = 77.74 µg/mL, SI ≥ 129), DENV3 (EC50 = 244 µg/mL, SI ≥ 41) and DENV4 (EC50 = 280 µg/mL, SI ≥ 36).