Bharat Biotech International’s intranasal Covid-19 vaccine candidate, if successful, can be a game-changer for not only the inoculation programme but also for the science of preventive medicines.
According to sources, the Hyderabad-based company — which made Covaxin, the first domestic vaccine for Covid-19 — is now looking at a totally new approach of using a single dose of intra-muscular Covaxin and another of the nasal vaccine in a method called the “heterologous prime boost”.
While a cocktail approach of administering two doses of two different vaccines is being considered, using a combination of one intra-muscular and the other nasal is an ‘innovative’ approach, a source said.
Nod for Phase-2 trials
The world’s first intranasal Covid-19 vaccine, codenamed BBV154, received regulatory nod for Phase-2 clinical trials in August. In the Phase-1 trials, BBV154 was tested on healthy individuals between 18 and 60 years of age. The successful completion of the remaining trials would make it possible to use the intranasal vaccine as a booster shot after a dose of Covaxin. BBV154 is an intranasal replication-deficient chimpanzee adenovirus SARS-CoV-2 vectored vaccine, which uses a technology licensed from the Washington University in St Louis, US.
Currently, BBV 154 is undergoing Phase-2 randomised, multi-centre clinical trial of heterologous prime-boost combination of SARS-CoV-2 vaccines to evaluate the immunogenicity and safety of Covaxin with BBV154 in healthy volunteers.
Given the huge task of vaccinating over a billion people in India, the intranasal vaccine offers convenience apart from simplifying logistics and vaccine administration. Further, as intranasal vaccines have the ability to activate alternative immunological pathways, it is possible that it can be taken by those who have already taken other intra-muscular vaccines as well.
Easing shortage issues
A heterologous prime boost approach will also ease the issue of vaccine shortage. Live adenovirus vectored vaccines are easier to manufacture compared to the inactivated vaccines. Plus, the intranasal route of delivery can address some of the safety issues related to live vectored vaccines administered intramuscular.
For Bharat Biotech, it is still fingers-crossed on the final outcome though it is ‘very positive and optimistic’ about the results. The data of the ongoing clinical trial of BBV154 are likely to be available in December.