Provisional findings hint that Covaxin may generate antibodies that may persist for 6-12 mths

Results have not yet undergone peer review, findings are provisional, and the conclusions/final results may differ

On December 21, Bharat Biotech provided study information on a preprint publishing website (https://www.medrxiv.org/content/10.1101/2020.12.21.20248643v1.full.pdf) according to which its COVID-19 vaccine candidate, Covaxin (BBV152) showed long-term antibody and T-cell memory responses ( three months after vaccination) in phase 1 volunteers, and tolerable safety outcomes with enhanced humoral and cell-mediated immune responses in the Phase 2 study.

The results from the phase 2 study show that both humoral and cell-mediated responses were observed. No neutralising antibody differences were observed between sexes and across age groups. BBV152 was well tolerated in both dose groups with no serious adverse events, as per the released findings.

It is important to note that these results have not yet undergone peer review, findings are provisional, and the conclusions/final results may differ. The paper on the Phase 1 and 2 trial data is concurrently undergoing scientific peer-review for potential publication by a medical peer reviewed journal.

Detailed findings under scientific peer-review

In a double-blind, randomised, multi-centre, phase 2 clinical trial a total of 380 healthy children and adults were randomised to receive two intramuscular doses of vaccine formulations (n=190 each) with 3 µg and 6 µg with Algel-IMDG, four weeks apart.

In a follow-up of the phase 1 trial, BBV152 produced high levels of neutralising antibodies that remained elevated in all participants three months (at day 104) after the second vaccination. Based on these results, the company hypothesises that BBV152 can generate antibodies that may persist for 6-12 months.

Higher neutralising titres (2-fold) was observed in the phase 2 study than in the phase 1 study.

Both vaccine groups reportedly elicited more Th1-biased cytokines than Th2-biased cytokines.

After two doses, local and systemic adverse reactions observed in both vaccine groups were minimal, and the majority of them resolved within 24 hours of onset. No serious adverse events were reported in this study, as per the pre-print findings.

The vaccine candidate is currently part of a Phase 3 clinical trial in India and recruiting 26,000 volunteers.

Potentially “broader coverage” leads to co-development tie up with Ocugen for US market

The Hyderabad-based company recently signed a binding letter of intent (LOI) with US based Ocugen to co-develop Covaxin for the US market.

As per the LOI, Ocugen will have US rights to the vaccine candidate and, in collaboration with Bharat Biotech, will be responsible for clinical development, registration, and commercialisation for the US market. According to a company statement, the companies have begun collaborating and will finalise details of the definitive agreement in the next few weeks. This collaboration leverages Ocugen’s vaccine expertise, and its R&D and regulatory capabilities in the US.

In preparation for the development of Covaxin in the US, Ocugen has assembled a Vaccine Scientific Advisory Board featuring leading academic and industry experts to evaluate the clinical and regulatory path to approval in the US market.

Explaining the rationale for the collaboration, Harvey Rubin, M.D. Ph.D. of the University of Pennsylvania, a member of Ocugen’s Vaccine Scientific Advisory Board said, “Covaxin utilises a historically proven approach to vaccine design. The adjuvanted inactivated virus vaccine candidate elicited strong IgG responses against spike (S1) protein, receptor-binding domain (RBD) and the nucleocapsid (N) protein of SARS-CoV-2 along with strong cellular responses in Phase 1 and 2 clinical trials. Covaxin offers a vaccine candidate that is different from other options currently available in the US market with potentially broader coverage against multiple protein antigens of the virus.”

David Fajgenbaum, M.D. of University of Pennsylvania’s Division of Translational Medicine & Human Genetics, Director of the Center for Cytokine Storm Treatment & Laboratory, and member of Ocugen’s Vaccine Scientific Advisory Board said, “The COVID-19 pandemic has caused unmatched devastation to individual patients and to the world. It is going to take the kind of unmatched collaboration and innovation that is occurring right now to effectively fight back. Vaccines such as Covaxin that can potentially elicit a broad immune response and may limit future COVID-19 severity could be important to have in our arsenal.”

“We are delighted to collaborate with Bharat Biotech to potentially bring Covaxin the US market. In the face of the coronavirus pandemic, it is incumbent upon all of us to find solutions that have the potential to save lives and restore normalcy to our day-to-day activities. We have been very pleased with the safety and immunogenicity demonstrated by the Phase 1 and Phase 2 trials of Covaxin and are encouraged with the progress of the Phase 3 trials in India. We believe this unique yet traditional approach to vaccination holds great potential to appeal to a broad range of the population,” said Dr Shankar Musunuri, Chairman, CEO, and Co-Founder, Ocugen.

“The development and clinical evaluation of Covaxin marks a significant milestone for vaccinology in India. Covaxin has garnered interest from several countries worldwide for supplies and introduction and we are excited to collaborate with Ocugen to bring it to the US market,” said Dr. Krishna Ella, Chairman & Managing Director, Bharat Biotech.