Booster dose: Bharat Biotech's nasal vaccine may be used with Covaxin

Bharat Biotech is working on a three-legged clinical trial for its intranasal vaccine BBV154, which is in phase two. The Hyderabad-based firm is testing the efficacy of a combination in three modes – two intranasal shots, first a Covaxin shot followed by the nasal vaccine, and Covaxin following a nasal shot.
 
The idea is to see which combination induces better and long-lasting immune response. Therefore, the intranasal vaccine could be used as a combination with the intramuscular Covaxin shot.
 
“While the nasal vaccine can be administered as two shots, the company is testing whether combining it with Covaxin gives better results. Thus, this can be used as a mix-and-match with Covaxin to produce a more holistic immune response,” the source said.

 

The company did not answer some queries sent by Business Standard till the time of going to press.
 
The two vaccines have different mechanisms of action and trigger slightly different immune responses.
 
Shahid Jameel, senior virologist and director at Ashoka University, said a different kind of antibodies protects the nasal mucosa – these are called IgA antibodies. “This is not sufficiently generated when a vaccine is administered through the intramuscular route,” Jameel said.
 
Commenting on the nasal vaccine, Jacob John, former head of Centre for Advanced Research in Virology at the Indian Council of Medical Research (ICMR), said to have a nasal vaccine is a ‘fantastic idea’ for two reasons — one, it can potentially create sterile immunity, and two, it is easy to administer and thus scalable.