Phase III randomized clinical studies to evaluate the immunogenicity, lot-to-lot consistency, and safety of ROTAVAC® liquid formulations (ROTAVAC 5C & 5D) and non-inferiority comparisons with licensed ROTAVAC® (frozen formulation) in healthy infants

The WHO pre-qualified rotavirus vaccine, ROTAVAC®, is derived naturally from the neonatal 116E rotavirus strain, and stored at -20°C. As refrigerator storage is preferable, immunogenicity and safety of liquid formulations kept at 2-8°C, having excipients to stabilize the rotavirus, with or without buffers, were compared with ROTAVAC® in different clinical studies. Study-1, the pivotal trial for this entire product development work, was a randomized, single-blind trial with two operationally seamless phases: (i) an exploratory phase involving 675 infants in which two formulations, ROTAVAC 5C (LnHRV-1.5 mL and LnHRV-2.0 mL) containing buffer and excipients to stabilize the virus against gastric acidity and temperature, were compared with ROTAVAC®. As the immune response of ROTAVAC 5C (LnHRV-2.0 mL) was non-inferior to ROTAVAC®, it was selected for (ii) confirmatory phase, involving 1,302 infants randomized 1:1:1:1 to receive three lots of LnHRV-2.0 mL, or ROTAVAC®. Primary objectives were the evaluation of non-inferiority and lot-to-lot consistency. The secondary objectives were to assess the safety and interference with the concomitant pentavalent vaccine. As it was separately established that buffers are not required for ROTAVAC®, in Study-2, the safety and immunogenicity of ROTAVAC 5D® (with excipients) were compared with ROTAVAC® and lot-to-lot consistency was assessed in another study. All lots elicited consistent immune responses, did not interfere with UIP vaccines, and had reactogenicity similar to ROTAVAC®. ROTAVAC 5C and ROTAVAC 5D® were immunogenic and well tolerated as ROTAVAC®. ROTAVAC 5D® had comparable immunogenicity and safety profiles with ROTAVAC® and can be stored at 2-8°C, leading to WHO pre-qualification.Clinical Trials Registration: Clinical Trials Registry of India (CTRI): CTRI/2015/02/005577CTRI/2016/11/007481 and CTRI/2019/03/017934.

Phase III Pivotal comparative clinical trial of intranasal (iNCOVACC) and intramuscular COVID 19 vaccine (Covaxin®)

One of the most preferable characteristics for a COVID-19 vaccine candidate is the ability to reduce transmission and infection of SARS-CoV-2, in addition to disease prevention. Unlike intramuscular vaccines, intranasal COVID-19 vaccines may offer this by generating mucosal immunity. In this open-label, randomised, multicentre, phase 3 clinical trial (CTRI/2022/02/40065; ClinicalTrials.gov: NCT05522335), healthy adults were randomised to receive two doses, 28 days apart, of either intranasal adenoviral vectored SARS-CoV-2 vaccine (BBV154) or licensed intramuscular vaccine, Covaxin®. Between April 16 and June 4, 2022, we enrolled 3160 subjects of whom, 2971 received 2 doses of BBV154 and 161 received Covaxin. On Day 42, 14 days after the second dose, BBV154 induced significant serum neutralization antibody titers against the ancestral (Wuhan) virus, which met the pre-defined superiority criterion for BBV154 over Covaxin®. Further, both vaccines showed cross protection against Omicron BA.5 variant. Salivary IgA titers were found to be higher in BBV154. In addition, extensive evaluation of T cell immunity revealed comparable responses in both cohorts due to prior infection. However, BBV154 showed significantly more ancestral specific IgA-secreting plasmablasts, post vaccination, whereas Covaxin recipients showed significant Omicron specific IgA-secreting plasmablasts only at day 42. Both vaccines were well tolerated. Overall reported solicited reactions were 6.9% and 25.5% and unsolicited reactions were 1.2% and 3.1% in BBV154 and Covaxin® participants respectively.

Preclinical evaluation of safety and immunogenicity of a primary series intranasal COVID-19 vaccine candidate (BBV154) and humoral immunogenicity evaluation of a heterologous prime-boost strategy with COVAXIN (BBV152)

Most if not all vaccine candidates developed to combat COVID-19 due to SARS-CoV-2 infection are administered parenterally. As SARS-CoV-2 is transmitted through infectious respiratory fluids, vaccine-induced mucosal immunity could provide an important contribution to control this pandemic. ChAd-SARS-CoV-2-S (BBV154), a replication-defective chimpanzee adenovirus (ChAd)-vectored intranasal (IN) COVID-19 vaccine candidate, encodes a prefusion-stabilized version of the SARS-CoV-2 spike protein containing two proline substitutions in the S2 subunit. We performed preclinical evaluations of BBV154 in mice, rats, hamsters and rabbits. Repeated dose toxicity studies presented excellent safety profiles in terms of pathology and biochemical analysis. IN administration of BBV154 elicited robust mucosal and systemic humoral immune responses coupled with Th1 cell-mediated immune responses. BBV154 IN vaccination also elicited potent variant (omicron) cross neutralization antibodies. Assessment of anti-vector (ChAd36) neutralizing antibodies following repeated doses of BBV154 IN administration showed insignificant titers of ChAd36 neutralizing antibodies. However, the immune sera derived from the same animals displayed significantly higher levels of SARS-CoV-2 virus neutralization (p<0.003). We also evaluated the safety and immunogenicity of heterologous prime-boost vaccination with intramuscular (IM) COVAXIN-prime followed by BBV154 IN administration. COVAXIN priming followed by BBV154 IN-booster showed an acceptable reactogenicity profile comparable to the homologous COVAXIN/COVAXIN or BBV154/BBV154 vaccination model. Heterologous vaccination of COVAXIN-prime and BBV154 booster also elicited superior (p<0.005) and cross variant (omicron) protective immune responses (p<0.013) compared with the homologous COVAXIN/COVAXIN schedule. BBV154 has successfully completed both homologous and heterologous combination schedules of human phase 3 clinical trials and received the restricted emergency use approval (in those aged above 18 years) from the Drugs Controller General of India (DCGI).

Persistence of immunity and impact of third dose of inactivated COVID-19 vaccine against emerging variants

This is a comprehensive report on immunogenicity of COVAXIN^® booster dose against ancestral and Variants of Concern (VOCs) up to 12 months. It is well known that neutralizing antibodies induced by COVID-19 vaccines wane within 6 months of vaccination leading to questions on the effectiveness of two-dose vaccination against breakthrough infections. Therefore, we assessed the persistence of immunogenicity up to 6 months after a two or three-dose with BBV152 and the safety of a booster dose in an ongoing phase 2, double-blind, randomized controlled trial (ClinicalTrials.gov: NCT04471519). We report persistence of humoral and cell mediated immunity up to 12 months of vaccination, despite decline in the magnitude of antibody titers. Administration of a third dose of BBV152 increased neutralization titers against both homologous (D614G) and heterologous strains (Alpha, Beta, Delta, Delta Plus and Omicron) with a slight increase in B cell memory responses. Thus, seronversion rate remain high in boosted recipients compared to non-booster, even after 6 months, post third dose against variants. No serious adverse events observed, except pain at the injection site, itching and redness. Hence, these results indicate that a booster dose of BBV152 is safe and necessary to ensure persistent immunity to minimize breakthrough infections of COVID-19, due to newly emerging variants.

Trial registration: Registered with the Clinical Trials Registry (India) No. CTRI/2021/04/032942, dated 19/04/2021 and on Clinicaltrials.gov: NCT04471519.

Immunogenicity and reactogenicity of an inactivated SARS-CoV-2 vaccine (BBV152) in children aged 2–18 years: interim data from an open-label, non-randomised, age de-escalation phase 2/3 study

Background

Despite having milder symptoms than adults, children are still susceptible to and can transmit SARS-CoV-2. Vaccination across all age groups is therefore necessary to curtail the pandemic. Among the available COVID-19 vaccine platforms, an inactivated vaccine platform has the advantage of excellent safety profile across all age groups; hence, we conducted an age de-escalation study to assess the safety, reactogenicity, and immunogenicity of an inactivated COVID-19 vaccine, BBV152 (COVAXIN; Bharat Biotech International, Hyderabad, India), in children aged 2–18 years.

Methods

In this phase 2/3 open-label, non-randomised, multicentre study done in six hospitals in India, healthy children (male or female) aged 2–18 years were eligible for inclusion into the study. Children who had positive SARS-CoV-2 nucleic acid and serology tests at baseline, or any history of previous SARS-CoV-2 infection, or with known immunosuppressive condition were excluded. Children were sequentially enrolled into one of three groups (>12 to ≤18 years [group 1], >6 to 12 years [group 2], or ≥2 to 6 years [group 3]) and administered with adult formulation of BBV152 as two 0·5 mL intramuscular doses on days 0 and 28. Co-primary endpoints were solicited adverse events for 7 days post-vaccination and neutralising antibody titres on day 56, 28 days after the second dose. Immunogenicity endpoints were compared with Biodefense and Emerging Infections, Research Resources Repository (BEI) reference serum samples and from adults who received two doses of BBV152 in the same schedule in a previously reported phase 2 study. The trial is registered with the Clinical Trials Registry, India (CTRI/2021/05/033752) and ClinicalTrials.gov (NCT04918797).

Findings

From May 27, 2021, to July 10, 2021, we enrolled 526 children sequentially into groups 1 (n=176), 2 (n=175), and 3 (n=175). Vaccination was well tolerated, with no differences in reactogenicity between the three age groups, and no serious adverse events, deaths, or withdrawals due to an adverse event. Local reactions mainly consisted of mild injection site pain in 46 (26%) of 176 participants in group 1, 61 (35%) of 175 in group 2, and 39 (22%) of 175 in group 3 after dose 1; and 39 (22%) of 176 in group 1, 43 of 175 (25%) in group 2, and 14 of 175 (8%) in group 3 after dose 2; there were no cases of severe pain and few reports of other local reactions. After dose 1, the most frequent solicited systemic adverse event was mild-to-moderate fever, reported in eight (5%) of 176 participants in group 1, 17 (10%) of 175 in group 2, and 22 (13%) of 175 in group 3. No case of severe fever was reported, and rates of all fever were all 4% or less after dose 2. Geometric mean titres (GMTs) of microneutralisation antibodies at day 56 in groups 1 (138·8 [95% CI 111·0–173·6]), 2 (137·4 [99·1–167·5]), and 3 (197·6 [176·4–221·4]) were similar to titres in vaccinated adults (160·1 [135·8–188·8]) and with BEI reference serum samples (103·3 [50·3–202·1]). Similar results were obtained using the plaque reduction neutralisation test (PRNT), in which 166 (95%) of 175 participants in group 1, 165 (98%) of 168 in group 2, and 169 (98%) of 172 in group 3 seroconverted at day 56. The GMT ratio of PRNT titres in children and adults was 1·76 (95% CI 1·32–2·33), indicating a superior response in children compared with adults.

Interpretation

BBV152 was well tolerated in children aged 2–18 years, and induced higher neutralising antibody responses than those observed in adults, in whom the efficacy (ie, the prevention or decrease in the severity of COVID-19 infection) has been demonstrated.

Funding

Bharat Biotech International.

Booster dose of the inactivated COVID-19 vaccine BBV152 (Covaxin) enhances the neutralizing antibody response against Alpha, Beta, Delta and Omicron variants of concern

The neutralizing antibody responses were significantly elevated after 3rd dose of BBV152/Covaxin against the B.1 (19.11 fold) variant including Delta (16.51 fold), Beta (14.70 fold) and Omicron (18.53 fold) Variants of concern in comparison with two dose vaccine, providing assurance of a protective immune response of booster in recipients.

Efficacy, safety, and lot-to-lot immunogenicity of an inactivated SARS-CoV-2 vaccine (BBV152): interim results of a randomised, double-blind, controlled, phase 3 trial

BACKGROUND

We report the clinical efficacy against COVID-19 infection of BBV152, a whole virion inactivated SARS-CoV-2 vaccine formulated with a toll-like receptor 7/8 agonist molecule adsorbed to alum (Algel-IMDG) in Indian adults.

METHODS

We did a randomised, double-blind, placebo-controlled, multicentre, phase 3 clinical trial in 25 Indian hospitals or medical clinics to evaluate the efficacy, safety, and immunological lot consistency of BBV152. Adults (age ≥18 years) who were healthy or had stable chronic medical conditions (not an immunocompromising condition or requiring treatment with immunosuppressive therapy) were randomised 1:1 with a computer-generated randomisation scheme (stratified for the presence or absence of chronic conditions) to receive two intramuscular doses of vaccine or placebo administered 4 weeks apart. Participants, investigators, study coordinators, study-related personnel, the sponsor, and nurses who administered the vaccines were masked to treatment group allocation; an unmasked contract research organisation and a masked expert adjudication panel assessed outcomes. The primary outcome was the efficacy of the BBV152 vaccine in preventing a first occurrence of laboratory-confirmed (RT-PCR-positive) symptomatic COVID-19 (any severity), occurring at least 14 days after the second dose in the per-protocol population. We also assessed safety and reactogenicity throughout the duration of the study in all participants who had received at least one dose of vaccine or placebo. This report contains interim results (data cutoff May 17, 2021) regarding immunogenicity and safety outcomes (captured on days 0 to 56) and efficacy results with a median of 99 days for the study population. The trial was registered on the Indian Clinical Trials Registry India, CTRI/2020/11/028976, and ClinicalTrials.gov, NCT04641481 (active, not recruiting).

FINDINGS

Between Nov 16, 2020, and Jan 7, 2021, we recruited 25 798 participants who were randomly assigned to receive BBV152 or placebo; 24 419 received two doses of BBV152 (n=12 221) or placebo (n=12 198). Efficacy analysis was dependent on having 130 cases of symptomatic COVID-19, which occurred when 16 973 initially seronegative participants had at least 14 days follow-up after the second dose. 24 (0·3%) cases occurred among 8471 vaccine recipients and 106 (1·2%) among 8502 placebo recipients, giving an overall estimated vaccine efficacy of 77·8% (95% CI 65·2-86·4). In the safety population (n=25 753), 5959 adverse events occurred in 3194 participants. BBV152 was well tolerated; the same proportion of participants reported adverse events in the vaccine group (1597 [12·4%] of 12 879) and placebo group (1597 [12·4%] of 12 874), with no clinically significant differences in the distributions of solicited, unsolicited, or serious adverse events between the groups, and no cases of anaphylaxis or vaccine-related deaths.

INTERPRETATION

BBV152 was highly efficacious against laboratory-confirmed symptomatic COVID-19 disease in adults. Vaccination was well tolerated with no safety concerns raised in this interim analysis.

FUNDING

Bharat Biotech International and Indian Council of Medical Research.

Persisting antibody responses to Vi polysaccharide-tetanus toxoid conjugate (Typbar TCV®) vaccine up to 7 years following primary vaccination of children < 2 years of age with, or without, a booster vaccination

BACKGROUND

Serum IgG anti-Vi titers attained by 327 children 6-23 months of age immunized with Vi polysaccharide-tetanus toxoid conjugate vaccine (Typbar TCV®), of whom 193/327 received a booster dose 2 years post-primary vaccination, were previously reported.

METHODS

Anti-Vi IgG in boosted and unboosted children 3, 5, and 7 years post-primary immunization were monitored using three different enzyme-linked immunosorbent assays (ELISAs): Vacczyme™ kit ELISA (all specimens); "Szu" ELISA (all specimens), and National Institute of Biological Standards NIBSC ELISA (subset). Endpoints analyzed included: persisting seroconversion (titer remaining ≥ 4-fold above baseline), geometric mean titer (GMT), geometric mean-fold rise post-vaccination, and percent exhibiting putative protective anti-Vi level (≥2 µg_Szu/ml) using Szu method and National Institutes of Health IgG reference standard. In assessing the persistence of elevated anti-Vi titers stimulated by Typbar-TCV®, four subgroups were compared based on whether or not the initially enrolled children were boosted on day 720 and whether they provided serum on all key timepoints, or if they missed one or more timepoints: i) Among boosted participants, an "All Specimens Cohort" (ASC) comprised 86 children who provided sera on days 42, 720 (booster), 762 (42 days post-booster), 1095, 1825 and 2555, to define kinetics of the Vi antibody response in a fully compliant cohort of boosted children monitored over seven years; ii) Among non-boosted subjects, a compliant All Specimens Cohort of 25 children provided sera on days 0, 42, 720, 1095, 1825, and 2555; iii) Among boosted children, an "Any Available Specimen" (AAS) subgroup consisted of boosted children who provided sera on days 0, 42, and 720 days and also on one or more of days 762, 1095, 1825, or 2555 but not on all those time points; iv) Among the non-boosted subjects, there was also an Any Available Specimen subgroup of 47 children who provided sera on days 0 and 42, of whom 41 subsequently contributed sera on one or more of days 1095, 1825 and 2555.

RESULTS

Vacczyme™ GMTs among boosted ASC children (N = 86) increased significantly on day 762, and remained 32-fold, 14-fold, and 10-fold over baseline at 3, 5 and 7 years; among unboosted ASC children (N = 25), GMTs remained 21-fold, 8-fold and 5-fold over baseline, respectively. Post-primary vaccination, 72% and 44% of unboosted ASC subjects (N = 25) exhibited persisting seroconversion by Vacczyme™ at 5 and 7 years, respectively; the corresponding numbers for ASC boosted subjects were 84% and 71%. Amongst the four sub-groups, boosted subjects showed higher prevalence of persisting seroconversion at most time points with the gap widening by 7th year, though not statistically significant (except 3rd year). Tested by Szu and also NIBSC ELISAs, 92-100% of unboosted ASC children showed persisting seroconversion at 7 years with 100% also exceeding the Szu protective threshold.

CONCLUSION

To extend protection, administering a booster of Typbar TCV® to children ∼5 years after their primary dose, i.e., coinciding with school entry, may be advisable. Typbar TCV® is presently the only WHO pre-qualified Vi conjugate vaccine with reported efficacy, effectiveness, and long-term immunogenicity findings.

Neutralization of VUI B.1.1.28 P2 variant with sera of COVID-19 recovered cases and recipients of Covaxin an inactivated COVID-19 vaccine

Our study has shown 1.09 and 1.92 fold reductions in the neutralizing titer with sera of individuals with natural infection and Covaxin vaccine recipients against B.1.1.28.2 variant.

Neutralization of Beta and Delta variant with sera of COVID-19 recovered cases and vaccinees of inactivated COVID-19 vaccine BBV152/Covaxin

SARS-CoV-2 variant of concern mainly Delta and Beta is global public health concern due to its impact on existing vaccines. Here, we assessed the neutralization of sera from COVID-19 recovered cases and BBV152 vaccinees against Beta and Delta variants. BBV152 vaccine found to confer significant protection against both the variants.

A multi-centre, post-marketing surveillance study of Vi polysaccharide-tetanus toxoid conjugate vaccine (Typbar TCV®) in India

A typhoid Vi capsular-polysaccharide tetanus toxoid conjugate vaccine (Typbar-TCV®) was recommended by the World Health Organization for use in children >6 months of age. The present post-marketing surveillance study was intended to assess the clinical safety of approximately 11 million doses of TCV sold till 2019 in a diverse age range Indian population. Both active and passive post-marketing surveillance studies were conducted at multiple centers. Active surveillance was performed in two periods, Period-I: February to October 2016, Period-II: April 2017 to October 2018. In Period-II, the Brighton Collaboration Criteria adverse event case definitions were used. Passive surveillance was performed from February 2016 to December 2019 through voluntary reporting by pediatricians across India. During the active surveillance, 1147 adverse events were reported among 4,991 (23.0%) subjects in Period-I, and 596 adverse events among 3898 (21.3%) subjects in Period-II. The most frequent adverse events were fever (9.2% and 12.02%in Periods I and II, respectively), pain at the injection site (8.3% and 7.33%), and swelling (4.0% and 1.93%). No serious adverse events (SAEs) were reported during either Period. Passive surveillance revealed 235 adverse events, including 25 SAEs requiring hospitalization, of which two were due to typhoid fever. All the events mentioned above occurred within one week of vaccination, and all the subjects have recovered from AEs with medications. All reported adverse events resolved with no clinical sequelae. Observations in this study are consistent with the pre-licensure studies with no additional safety signals detected, confirming that Typbar-TCV® is safe.

Abbreviations: AE: Adverse event; LMIC: low- and middle-income countries; PMS: Post-marketing surveillance; SAE: Serious adverse event; TCV: Vi-polysaccharide tetanus –toxoid conjugate vaccine (Typbar-TCV®)

Safety and immunogenicity of an inactivated SARS-CoV-2 vaccine, BBV152: interim results from a double-blind, randomised, multicentre, phase 2 trial, and 3-month follow-up of a double-blind, randomised phase 1 trial

BACKGROUND

BBV152 is a whole-virion inactivated SARS-CoV-2 vaccine (3 μg or 6 μg) formulated with a toll-like receptor 7/8 agonist molecule (IMDG) adsorbed to alum (Algel). We previously reported findings from a double-blind, multicentre, randomised, controlled phase 1 trial on the safety and immunogenicity of three different formulations of BBV152 (3 μg with Algel-IMDG, 6 μg with Algel-IMDG, or 6 μg with Algel) and one Algel-only control (no antigen), with the first dose administered on day 0 and the second dose on day 14. The 3 μg and 6 μg with Algel-IMDG formulations were selected for this phase 2 study. Herein, we report interim findings of the phase 2 trial on the immunogenicity and safety of BBV152, with the first dose administered on day 0 and the second dose on day 28.

METHODS

We did a double-blind, randomised, multicentre, phase 2 clinical trial to evaluate the immunogenicity and safety of BBV152 in healthy adults and adolescents (aged 12-65 years) at nine hospitals in India. Participants with positive SARS-CoV-2 nucleic acid and serology tests were excluded. Participants were randomly assigned (1:1) to receive either 3 μg with Algel-IMDG or 6 μg with Algel-IMDG. Block randomisation was done by use of an interactive web response system. Participants, investigators, study coordinators, study-related personnel, and the sponsor were masked to treatment group allocation. Two intramuscular doses of vaccine were administered on day 0 and day 28. The primary outcome was SARS-CoV-2 wild-type neutralising antibody titres and seroconversion rates (defined as a post-vaccination titre that was at least four-fold higher than the baseline titre) at 4 weeks after the second dose (day 56), measured by use of the plaque-reduction neutralisation test (PRNT₅₀) and the microneutralisation test (MNT₅₀). The primary outcome was assessed in all participants who had received both doses of the vaccine. Cell-mediated responses were a secondary outcome and were assessed by T-helper-1 (Th1)/Th2 profiling at 2 weeks after the second dose (day 42). Safety was assessed in all participants who received at least one dose of the vaccine. In addition, we report immunogenicity results from a follow-up blood draw collected from phase 1 trial participants at 3 months after they received the second dose (day 104). This trial is registered at ClinicalTrials.gov, NCT04471519.

FINDINGS

Between Sept 5 and 12, 2020, 921 participants were screened, of whom 380 were enrolled and randomly assigned to the 3 μg with Algel-IMDG group (n=190) or 6 μg with Algel-IMDG group (n=190). Geometric mean titres (GMTs; PRNT₅₀) at day 56 were significantly higher in the 6 μg with Algel-IMDG group (197·0 [95% CI 155·6-249·4]) than the 3 μg with Algel-IMDG group (100·9 [74·1-137·4]; p=0·0041). Seroconversion based on PRNT₅₀ at day 56 was reported in 171 (92·9% [95% CI 88·2-96·2] of 184 participants in the 3 μg with Algel-IMDG group and 174 (98·3% [95·1-99·6]) of 177 participants in the 6 μg with Algel-IMDG group. GMTs (MNT₅₀) at day 56 were 92·5 (95% CI 77·7-110·2) in the 3 μg with Algel-IMDG group and 160·1 (135·8-188·8) in the 6 μg with Algel-IMDG group. Seroconversion based on MNT₅₀ at day 56 was reported in 162 (88·0% [95% CI 82·4-92·3]) of 184 participants in the 3 μg with Algel-IMDG group and 171 (96·6% [92·8-98·8]) of 177 participants in the 6 μg with Algel-IMDG group. The 3 μg with Algel-IMDG and 6 μg with Algel-IMDG formulations elicited T-cell responses that were biased to a Th1 phenotype at day 42. No significant difference in the proportion of participants who had a solicited local or systemic adverse reaction in the 3 μg with Algel-IMDG group (38 [20·0%; 95% CI 14·7-26·5] of 190) and the 6 μg with Algel-IMDG group (40 [21·1%; 15·5-27·5] of 190) was observed on days 0-7 and days 28-35; no serious adverse events were reported in the study. From the phase 1 trial, 3-month post-second-dose GMTs (MNT₅₀) were 39·9 (95% CI 32·0-49·9) in the 3μg with Algel-IMDG group, 69·5 (53·7-89·9) in the 6 μg with Algel-IMDG group, 53·3 (40·1-71·0) in the 6 μg with Algel group, and 20·7 (14·5-29·5) in the Algel alone group.

INTERPRETATION

In the phase 1 trial, BBV152 induced high neutralising antibody responses that remained elevated in all participants at 3 months after the second vaccination. In the phase 2 trial, BBV152 showed better reactogenicity and safety outcomes, and enhanced humoral and cell-mediated immune responses compared with the phase 1 trial. The 6 μg with Algel-IMDG formulation has been selected for the phase 3 efficacy trial.

FUNDING

Bharat Biotech International.

TRANSLATION

For the Hindi translation of the abstract see Supplementary Materials section.

Safety and immunogenicity of an inactivated SARS-CoV-2 vaccine, BBV152: a double-blind, randomised, phase 1 trial

BACKGROUND

To mitigate the effects of COVID-19, a vaccine is urgently needed. BBV152 is a whole-virion inactivated SARS-CoV-2 vaccine formulated with a toll-like receptor 7/8 agonist molecule adsorbed to alum (Algel-IMDG) or alum (Algel).

METHODS

We did a double-blind, multicentre, randomised, controlled phase 1 trial to assess the safety and immunogenicity of BBV152 at 11 hospitals across India. Healthy adults aged 18-55 years who were deemed healthy by the investigator were eligible. Individuals with positive SARS-CoV-2 nucleic acid and/or serology tests were excluded. Participants were randomly assigned to receive either one of three vaccine formulations (3 μg with Algel-IMDG, 6 μg with Algel-IMDG, or 6 μg with Algel) or an Algel only control vaccine group. Block randomisation was done with a web response platform. Participants and investigators were masked to treatment group allocation. Two intramuscular doses of vaccines were administered on day 0 (the day of randomisation) and day 14. Primary outcomes were solicited local and systemic reactogenicity events at 2 h and 7 days after vaccination and throughout the full study duration, including serious adverse events. Secondary outcome was seroconversion (at least four-fold increase from baseline) based on wild-type virus neutralisation. Cell-mediated responses were evaluated by intracellular staining and ELISpot. The trial is registered at ClinicalTrials.gov (NCT04471519).

FINDINGS

Between July 13 and 30, 2020, 827 participants were screened, of whom 375 were enrolled. Among the enrolled participants, 100 each were randomly assigned to the three vaccine groups, and 75 were randomly assigned to the control group (Algel only). After both doses, solicited local and systemic adverse reactions were reported by 17 (17%; 95% CI 10·5-26·1) participants in the 3 μg with Algel-IMDG group, 21 (21%; 13·8-30·5) in the 6 μg with Algel-IMDG group, 14 (14%; 8·1-22·7) in the 6 μg with Algel group, and ten (10%; 6·9-23·6) in the Algel-only group. The most common solicited adverse events were injection site pain (17 [5%] of 375 participants), headache (13 [3%]), fatigue (11 [3%]), fever (nine [2%]), and nausea or vomiting (seven [2%]). All solicited adverse events were mild (43 [69%] of 62) or moderate (19 [31%]) and were more frequent after the first dose. One serious adverse event of viral pneumonitis was reported in the 6 μg with Algel group, unrelated to the vaccine. Seroconversion rates (%) were 87·9, 91·9, and 82·8 in the 3 μg with Algel-IMDG, 6 μg with Algel-IMDG, and 6 μg with Algel groups, respectively. CD4⁺ and CD8⁺ T-cell responses were detected in a subset of 16 participants from both Algel-IMDG groups.

INTERPRETATION

BBV152 led to tolerable safety outcomes and enhanced immune responses. Both Algel-IMDG formulations were selected for phase 2 immunogenicity trials. Further efficacy trials are warranted.

FUNDING

Bharat Biotech International.

Safety and immunogenicity of an inactivated SARS-CoV-2 vaccine, BBV152: a double-blind, randomised, phase 1 trial

BACKGROUND

To mitigate the effects of COVID-19, a vaccine is urgently needed. BBV152 is a whole-virion inactivated SARS-CoV-2 vaccine formulated with a toll-like receptor 7/8 agonist molecule adsorbed to alum (Algel-IMDG) or alum (Algel).

METHODS

We did a double-blind, multicentre, randomised, controlled phase 1 trial to assess the safety and immunogenicity of BBV152 at 11 hospitals across India. Healthy adults aged 18-55 years who were deemed healthy by the investigator were eligible. Individuals with positive SARS-CoV-2 nucleic acid and/or serology tests were excluded. Participants were randomly assigned to receive either one of three vaccine formulations (3 μg with Algel-IMDG, 6 μg with Algel-IMDG, or 6 μg with Algel) or an Algel only control vaccine group. Block randomisation was done with a web response platform. Participants and investigators were masked to treatment group allocation. Two intramuscular doses of vaccines were administered on day 0 (the day of randomisation) and day 14. Primary outcomes were solicited local and systemic reactogenicity events at 2 h and 7 days after vaccination and throughout the full study duration, including serious adverse events. Secondary outcome was seroconversion (at least four-fold increase from baseline) based on wild-type virus neutralisation. Cell-mediated responses were evaluated by intracellular staining and ELISpot. The trial is registered at ClinicalTrials.gov (NCT04471519).

FINDINGS

Between July 13 and 30, 2020, 827 participants were screened, of whom 375 were enrolled. Among the enrolled participants, 100 each were randomly assigned to the three vaccine groups, and 75 were randomly assigned to the control group (Algel only). After both doses, solicited local and systemic adverse reactions were reported by 17 (17%; 95% CI 10·5-26·1) participants in the 3 μg with Algel-IMDG group, 21 (21%; 13·8-30·5) in the 6 μg with Algel-IMDG group, 14 (14%; 8·1-22·7) in the 6 μg with Algel group, and ten (10%; 6·9-23·6) in the Algel-only group. The most common solicited adverse events were injection site pain (17 [5%] of 375 participants), headache (13 [3%]), fatigue (11 [3%]), fever (nine [2%]), and nausea or vomiting (seven [2%]). All solicited adverse events were mild (43 [69%] of 62) or moderate (19 [31%]) and were more frequent after the first dose. One serious adverse event of viral pneumonitis was reported in the 6 μg with Algel group, unrelated to the vaccine. Seroconversion rates (%) were 87·9, 91·9, and 82·8 in the 3 μg with Algel-IMDG, 6 μg with Algel-IMDG, and 6 μg with Algel groups, respectively. CD4⁺ and CD8⁺ T-cell responses were detected in a subset of 16 participants from both Algel-IMDG groups.

INTERPRETATION

BBV152 led to tolerable safety outcomes and enhanced immune responses. Both Algel-IMDG formulations were selected for phase 2 immunogenicity trials. Further efficacy trials are warranted.

FUNDING

Bharat Biotech International.

Th1 skewed immune response of whole virion inactivated SARS CoV 2 vaccine and its safety evaluation

We report the development and evaluation of safety and immunogenicity of a whole virion inactivated (WVI) SARS-CoV-2 vaccine (BBV152), adjuvanted with aluminum hydroxide gel (Algel), or TLR7/8 agonist chemisorbed Algel. We used a well-characterized SARS-CoV-2 strain and an established Vero cell platform to produce large-scale GMP-grade highly purified inactivated antigen. Product development and manufacturing process were carried out in a BSL-3 facility. Immunogenicity and safety were determined at two antigen concentrations (3μg and 6μg), with two different adjuvants, in mice, rats, and rabbits. Our results show that BBV152 vaccine formulations generated significantly high antigen-binding and neutralizing antibody titers (NAb), at both concentrations, in all three species with excellent safety profiles. The inactivated vaccine formulation contains TLR7/8 agonist adjuvant-induced Th1-biased antibody responses with elevated IgG2a/IgG1 ratio and increased levels of SARS-CoV-2-specific IFN-γ+ CD4+ T lymphocyte response. Our results support further development for phase I/II clinical trials in humans.

Persistence of Immune Responses With an Inactivated Japanese Encephalitis Single-Dose Vaccine, JENVAC and Interchangeability With a Live-Attenuated Vaccine

Background

This study reports immunogenicity, safety, and interchangeability of a single-dose, inactivated, Vero-cell derived, JENVAC to the live-attenuated SA 14-14-2 vaccine in healthy children.

Methods

This phase 4, multicenter, open-label, randomized, control trial enrolled 360 children who were equally randomized to receive a single dose of either JENVAC or SA 14-14-2. Children were followed at various time points, until 2 years (day 720) postvaccination, upon which a subset from each group was divided and allocated to a receive a booster dose or the other vaccine.

Results

At all time points, immunological measures were statistically higher in the JENVAC group. In the interchangeability study, children receiving 2 doses of JENVAC reported significantly higher response compared with 2 doses of SA 14-14-2. No difference in adverse events was observed. These corroborate with excellent seroprotection after the first dose of an earlier JENVAC study.

Conclusions

A single-dose vaccination with JENVAC induces protective titers that persist up to 1 year. We report appreciable interchangeability between both vaccines, with JENVAC/JENVAC combination exhibiting the highest immune response. JENVAC is now licensed as a single-dose Japanese encephalitis vaccine.

Safety and immunogenicity of an inactivated SARS-CoV-2 vaccine, BBV152: interim results from a double-blind, randomised, multicentre, phase 2 trial, and 3-month follow-up of a double-blind, randomised phase 1 trial

Background

BBV152 is a whole-virion inactivated SARS-CoV-2 vaccine (3 μg or 6 μg) formulated with a toll-like receptor 7/8 agonist molecule (IMDG) adsorbed to alum (Algel). We previously reported findings from a double-blind, multicentre, randomised, controlled phase 1 trial on the safety and immunogenicity of three different formulations of BBV152 (3 μg with Algel-IMDG, 6 μg with Algel-IMDG, or 6 μg with Algel) and one Algel-only control (no antigen), with the first dose administered on day 0 and the second dose on day 14. The 3 μg and 6 μg with Algel-IMDG formulations were selected for this phase 2 study. Herein, we report interim findings of the phase 2 trial on the immunogenicity and safety of BBV152, with the first dose administered on day 0 and the second dose on day 28.

Methods

We did a double-blind, randomised, multicentre, phase 2 clinical trial to evaluate the immunogenicity and safety of BBV152 in healthy adults and adolescents (aged 12–65 years) at nine hospitals in India. Participants with positive SARS-CoV-2 nucleic acid and serology tests were excluded. Participants were randomly assigned (1:1) to receive either 3 μg with Algel-IMDG or 6 μg with Algel-IMDG. Block randomisation was done by use of an interactive web response system. Participants, investigators, study coordinators, study-related personnel, and the sponsor were masked to treatment group allocation. Two intramuscular doses of vaccine were administered on day 0 and day 28. The primary outcome was SARS-CoV-2 wild-type neutralising antibody titres and seroconversion rates (defined as a post-vaccination titre that was at least four-fold higher than the baseline titre) at 4 weeks after the second dose (day 56), measured by use of the plaque-reduction neutralisation test (PRNT₅₀) and the microneutralisation test (MNT₅₀). The primary outcome was assessed in all participants who had received both doses of the vaccine. Cell-mediated responses were a secondary outcome and were assessed by T-helper-1 (Th1)/Th2 profiling at 2 weeks after the second dose (day 42). Safety was assessed in all participants who received at least one dose of the vaccine. In addition, we report immunogenicity results from a follow-up blood draw collected from phase 1 trial participants at 3 months after they received the second dose (day 104). This trial is registered at ClinicalTrials.gov, NCT04471519.

Findings

Between Sept 5 and 12, 2020, 921 participants were screened, of whom 380 were enrolled and randomly assigned to the 3 μg with Algel-IMDG group (n=190) or 6 μg with Algel-IMDG group (n=190). Geometric mean titres (GMTs; PRNT₅₀) at day 56 were significantly higher in the 6 μg with Algel-IMDG group (197·0 [95% CI 155·6–249·4]) than the 3 μg with Algel-IMDG group (100·9 [74·1–137·4]; p=0·0041). Seroconversion based on PRNT₅₀ at day 56 was reported in 171 (92·9% [95% CI 88·2–96·2] of 184 participants in the 3 μg with Algel-IMDG group and 174 (98·3% [95·1–99·6]) of 177 participants in the 6 μg with Algel-IMDG group. GMTs (MNT₅₀) at day 56 were 92·5 (95% CI 77·7–110·2) in the 3 μg with Algel-IMDG group and 160·1 (135·8–188·8) in the 6 μg with Algel-IMDG group. Seroconversion based on MNT₅₀ at day 56 was reported in 162 (88·0% [95% CI 82·4–92·3]) of 184 participants in the 3 μg with Algel-IMDG group and 171 (96·6% [92·8–98·8]) of 177 participants in the 6 μg with Algel-IMDG group. The 3 μg with Algel-IMDG and 6 μg with Algel-IMDG formulations elicited T-cell responses that were biased to a Th1 phenotype at day 42. No significant difference in the proportion of participants who had a solicited local or systemic adverse reaction in the 3 μg with Algel-IMDG group (38 [20·0%; 95% CI 14·7–26·5] of 190) and the 6 μg with Algel-IMDG group (40 [21·1%; 15·5–27·5] of 190) was observed on days 0–7 and days 28–35; no serious adverse events were reported in the study. From the phase 1 trial, 3-month post-second-dose GMTs (MNT₅₀) were 39·9 (95% CI 32·0–49·9) in the 3μg with Algel-IMDG group, 69·5 (53·7–89·9) in the 6 μg with Algel-IMDG group, 53·3 (40·1–71·0) in the 6 μg with Algel group, and 20·7 (14·5–29·5) in the Algel alone group.

Interpretation

In the phase 1 trial, BBV152 induced high neutralising antibody responses that remained elevated in all participants at 3 months after the second vaccination. In the phase 2 trial, BBV152 showed better reactogenicity and safety outcomes, and enhanced humoral and cell-mediated immune responses compared with the phase 1 trial. The 6 μg with Algel-IMDG formulation has been selected for the phase 3 efficacy trial.

Funding

Bharat Biotech International.

Translation

For the Hindi translation of the abstract see Supplementary Materials section.

Immunogenicity and protective efficacy of inactivated SARS-CoV-2 vaccine candidate, BBV152 in rhesus macaques

The COVID-19 pandemic is a global health crisis that poses a great challenge to the public health system of affected countries. Safe and effective vaccines are needed to overcome this crisis. Here, we develop and assess the protective efficacy and immunogenicity of an inactivated SARS-CoV-2 vaccine in rhesus macaques. Twenty macaques were divided into four groups of five animals each. One group was administered a placebo, while three groups were immunized with three different vaccine candidates of BBV152 at 0 and 14 days. All the macaques were challenged with SARS-CoV-2 fourteen days after the second dose. The protective response was observed with increasing SARS-CoV-2 specific IgG and neutralizing antibody titers from 3^rd-week post-immunization. Viral clearance was observed from bronchoalveolar lavage fluid, nasal swab, throat swab and lung tissues at 7 days post-infection in the vaccinated groups. No evidence of pneumonia was observed by histopathological examination in vaccinated groups, unlike the placebo group which exhibited interstitial pneumonia and localization of viral antigen in the alveolar epithelium and macrophages by immunohistochemistry. This vaccine candidate BBV152 has completed Phase I/II (NCT04471519) clinical trials in India and is presently in phase III, data of this study substantiates the immunogenicity and protective efficacy of the vaccine candidates.

Immunogenicity and protective efficacy of BBV152, whole virion inactivated SARS- CoV-2 vaccine candidates in the Syrian hamster model

The availability of a safe and effective vaccine would be the eventual measure to deal with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) threat. Here, we have assessed the immunogenicity and protective efficacy of inactivated SARS-CoV-2 vaccine candidates BBV152A, BBV152B, and BBV152C in Syrian hamsters. Three dose vaccination regimes with vaccine candidates induced significant titers of SARS-CoV-2-specific IgG and neutralizing antibodies. BBV152A and BBV152B vaccine candidates remarkably generated a quick and robust immune response. Post-SARS-CoV-2 infection, vaccinated hamsters did not show any histopathological changes in the lungs. The protection of the hamster was evident by the rapid clearance of the virus from lower respiratory tract, reduced virus load in upper respiratory tract, absence of lung pathology, and robust humoral immune response. These findings confirm the immunogenic potential of the vaccine candidates and further protection of hamsters challenged with SARS-CoV-2. Of the three candidates, BBV152A showed the better response.

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Vaccine candidates, BBV152 induced potent humoral immune response in Syrian hamsters

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Early viral clearance from lower respiratory tract in vaccinated hamsters

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BBV152 vaccine candidates protected Syrian hamsters from pneumonia

A randomized, open-labelled, non-inferiority phase 4 clinical trial to evaluate the immunogenicity and safety of the live, attenuated, oral rotavirus vaccine, ROTAVAC® in comparison with a licensed rotavirus vaccine in healthy infants

BACKGROUND

ROTAVAC® (nHRV), derived naturally from the human 116E rotavirus (RV) neonatal strain, was licensed in India in 2015 based on promising results of a phase 3, safety and efficacy vaccine trial. As a pre-requisite for WHO prequalification, we compared the immunogenicity and safety of ROTAVAC® to those of a WHO-prequalified, Rotarix®.

METHODS

We conducted a multicentre, open-labeled, randomized phase 4 clinical trial where 464 infants, 6-8 weeks of age were equally randomized to receive as licensed, the complete regimen of ROTAVAC® (3 doses; Group I) or Rotarix® (2 doses; Group II). Antibody responses (serum anti-RV Immunoglobulin A [IgA]) were measured by enzyme-linked immunosorbent assay (ELISA). The primary analysis was an assessment of non-inferiority of ROTAVAC® to Rotarix® for geometric mean concentration (GMC) for infants who received the complete regimen of either vaccine.

RESULTS

The GMC for Group I was 20.4 (95%CI: 17.6, 23.6) and that for Group II was 24.8 (95%CI: 20.3, 30.3), the GMC ratio was 0.82 (95% CI: 0.64, 1.05), thus meeting the non-inferiority criterion. Site-wise analysis of GMC titres revealed that one site had a peculiar pre-vaccination titre affecting only ROTAVAC® post-vaccination GMCs. Seroconversion rates were 35.3% (95%CI: 29.0, 41.9) and 31.0% (95%CI: 25.1, 37.4) for Groups I and Group II, respectively. There was no substantive difference in safety profiles between both vaccines.

CONCLUSIONS

The complete regimen of ROTAVAC® demonstrated immunological non-inferiority to the complete regimen of Rotarix® with a clinically acceptable safety profile. Because the demand for RV vaccines is increasing as more countries are expanding their immunization schedules, the lack of need of a buffering agent, low dose volume (0.5 mL), non-interference with other concomitantly administered vaccines, and conformance with WHO-prequalification requirements provide ROTAVAC® the potential for widespread global usage. Post completion of this study, ROTAVAC® is now a WHO-prequalified vaccine.

CLINICAL TRIALS REGISTRATION

(CTRI Number: CTRI/2015/12/006428).

A Phase 4, multicentre, randomized, single-blind clinical trial to evaluate the immunogenicity of the live, attenuated, oral rotavirus vaccine (116E), ROTAVAC®, administered simultaneously with or without the buffering agent in healthy infants in India

BACKGROUND

The World Health Organization recommends that rotavirus vaccines should be included in all national immunization programs. Some currently licensed oral rotavirus vaccines contain a buffering agent (either as part of a ready-to-use liquid formulation or added during reconstitution) to reduce possible degradation of the vaccine virus in the infant gut, which poses several programmatic challenges (the large dose volume or the reconstitution requirement) during vaccine administration. Because ROTAVAC®, a WHO prequalified vaccine, was derived from the 116E neonatal strain, we evaluated the immunogenicity and safety of ROTAVAC® without buffer and ROTAVAC® with buffer in a phase 4, multicentre, single-blind, randomized clinical trial in healthy infants in India.

METHODS

900 infants, approximately 6, 10 and 14 weeks of age, were assigned to 3 groups to receive ROTAVAC® (0.5 mL dose) orally: (i) 2.5 mL of citrate-bicarbonate buffer 5 minutes prior to administration of ROTAVAC® (Group I), (ii) ROTAVAC®, alone, without any buffer (Group II), or (iii) ROTAVAC®, mixed with buffer immediately before administration (Group III). Non-inferiority was compared among the groups for differences in serological responses (detected by serum anti-rotavirus IgA) and safety.

RESULTS

Geometric mean titers post vaccination at day 84 (28 days after dose 3) were 19.6 (95%CI: 17.0, 22.7), 20.7 (95%CI: 17.9, 24) and 19.2 (95%CI: 16.8, 22.1) for groups I, II and III respectively. Further, seroconversion rates and distribution of adverse events were similar among groups.

CONCLUSIONS

Administration of ROTAVAC® at a 0.5 mL dose volume without buffering agent was shown to be well tolerated and immunogenic. Given the homologous nature of the strain, it is plausible that ROTAVAC® replicates well and confers immunity even without buffer administration.

Effects of alprazolam on cholecystokinin-tetrapeptide-induced panic and hypothalamic-pituitary-adrenal-axis activity: a placebo-controlled study

Cholecystokinin-tetrapeptide (CCK-4) induces panic attacks both in patients with panic disorder (PD) and healthy volunteers. It has been shown that panic elicited by CCK-4 is improved after treatment with antidepressants. Moreover, a reduction of CCK-4-induced panic has also been demonstrated after treatment with lorazepam in single subjects and after selective GABAergic treatment with vigabatrin. Although benzodiazepines are widely used as anxiolytics, no controlled study on the effects of benzodiazepines on CCK-4-induced panic symptoms is available so far. Therefore, we investigated the effects of alprazolam and placebo on CCK-4-induced panic symptoms in a double-blind, placebo-controlled study. A total of 30 healthy subjects were challenged with 50 microg CCK-4. Out of these 30 subjects, 26 showed a marked panic response to CCK-4. Subjects were rechallenged after a 7-day interval and treated with 1 mg alprazolam or placebo 1 h prior to the second CCK-4 challenge. Panic was assessed using the acute panic inventory (API) and a DSM-IV-derived panic symptom scale (PSS). Moreover, the number of reported symptoms and self-rated anxiety and arousal were recorded. We found a significant reduction of the API and PSS scores and of the number of reported symptoms compared to placebo. Moreover, compared to placebo the CCK-4-induced ACTH and cortisol release were significantly attenuated during the CCK-4 challenge after alprazolam treatment. However, also placebo treatment reduced CCK-4-induced anxiety and HPA-axis activation to a certain extent. In conclusion, our data show that alprazolam reduces CCK-4-induced panic, which supports the hypothesis of a possible interaction between the GABA and the CCK system.

The combined dexamethasone-CRH test before and after repetitive transcranial magnetic stimulation (rTMS) in major depression

BACKGROUND

Hypothalamic-pituitary-adrenocortical (HPA) dysregulation assessed by the combined dexamethasone corticotropin releasing hormone test (DEX/CRH test) has been demonstrated to normalize after successful antidepressant pharmacotherapy. Here, we investigated whether repetitive transcranial magnetic stimulation (rTMS) also leads to a normalization of HPA system activity in depressed patients.

METHODS

Thirty-seven medication free patients suffering from a major depressive episode (DSM-IV) underwent a DEX/CRH test before and after 13 daily sessions of left prefrontal rTMS in an open trial.

RESULTS

There was an overshoot of CRH-induced cortisol release that was not affected by rTMS treatment. Postdexamethasone cortisol levels prior to CRH challenge decreased in responders after rTMS treatment, whereas no change of CRH-induced adrenocorticotropic hormone (ACTH) and cortisol release in responders or nonresponders was observed.

CONCLUSIONS

The persisting HPA system hyperactivity after rTMS suggests a high risk for relapse and therefore argues for an immediate maintenance therapy in patients responding to this treatment.

Plasma gamma-amino-butyric acid (GABA) levels in cholecystokinine-tetrapeptide (CCK-4) induced anxiety

INTRODUCTION

Dysregulation of the GABA system is supposed to play an important role in the pathophysiology of panic disorder. Moreover, prior investigations revealed an association between GABA plasma levels and experimental induced panic with lactate. To evaluate a possible relationship between plasma GABA and CCK-4 induced panic plasma GABA levels in healthy volunteers were investigated.

METHODS

12 healthy subjects were challenged with 50 micro g CCK-4. Blood samples for determination of plasma GABA were drawn at baseline, 5 and 10 minutes after CCK-4 injection.

RESULTS

Plasma GABA levels did not change significantly during the CCK-4 challenge as revealed by ANOVA for repeated measurements. There was no correlation between baseline GABA levels and anxiogenic response to CCK-4.

CONCLUSION

In contrast to previous findings with lactate our study does not suggest a possible relationship between plasma GABA levels and experimental induced panic with CCK-4.