Indian Covid vaccine makers eye regulator nod for universal boosters

INTERNATIONAL DESK: Covid vaccine makers in India are now vying for positioning their vaccines as the heterologous booster shot that may be administered after two doses of any vaccine.

Bharat Biotech’s intranasal vaccine — expected to get a nod from the drug regulator this month — has been tested as both a preliminary dose and a mix-and-match booster after Covaxin. Similarly, Dr Reddy’s Laboratories (DRL) is planning to submit data related to using the Sputnik Light (single-dose version of the Russian vaccine Sputnik V) as a heterologous booster.

A universal booster or a heterologous booster means that the third shot of a vaccine given to an individual is different from the primary two doses.

In April, Serum Institute of India’s Chief Executive Officer Adar Poonawalla had indicated that it plans to conduct a trial to test the Covovax as a booster shot in a mix-and-match trial.

India formally allowed the mixing of vaccines or a heterologous boosting policy this week, with Biological E’s Corbevax becoming the first vaccine to be approved as a heterologous booster in adults who have taken two shots of Covishield or Covaxin.

Experts have endorsed the adoption of a mix-and-match boosting strategy for vaccines.

Shahid Jameel, senior research fellow at Green Templeton College at Oxford University, has said India must use science to update its booster policy.

The researcher had said last month that the recent data from Christian Medical College, Vellore study on mixing Covishield and Covaxin showed that Covishield after Covaxin was a far superior combination.

The National Technical Advisory Group on Immunisation allowed using Corbevax as a heterologous booster, paving the way for other vaccines to vie for the spot.

As for Hyderabad-based Bharat Biotech, its intranasal vaccine is based on the adenovirus vector platform and is distinct from Covaxin. The vaccine helps to trigger the generation of immunoglobulin A (IgA) antibodies which line the nasal mucosa.

Bharat Biotech claims the vaccine helps to reduce the transmission of the Sars-CoV-2 virus as it attacks the virus at its first point of entry – the nose and the upper respiratory tract.

It had conducted a three-leg Phase 2 clinical trial for its intranasal vaccine. The vaccine was tested in three combinations – two intranasal shots, first a Covaxin shot followed by the nasal vaccine, or Covaxin shot following a nasal shot.

The company has sought approval for its vaccine both as a primary shot and also as a booster dose.

It has plans to have an annual capacity of 1 billion doses of the intranasal vaccine and is also open to having global partners for its manufacturing and distribution.

DRL, meanwhile, is readying to submit data on the Sputnik Light as a universal booster to the Drugs Controller General of India. (Business Standard)