India should immediately mix and match the existing vaccines in order to accelerate the national vaccination drive before the third wave of Covid-19 hits the nation, says Kiran-Mazumdar Shaw, executive chairperson, Biocon and Biocon Biologics.

“I strongly believe you should get into a mix-and-match schedule. It is important to look into all the data that is being generated. It is clearly shown that the combination of viral vector vaccines with mRNA (messenger ribonucleic acid) vaccines or sub-unit vaccines are much better than just using two doses of the same vaccine,” Shaw tells Fortune India.

With only 39 crore people vaccinated in the country, of which 31.25 crore have received their first jabs while 7.76 crore their second dose, the proportion of fully vaccinated citizens is at a dismal 6.2% as of July 14.

The Biocon chief feels studies have shown that a combination of a viral vector and mRNA vaccine is much better than 2 mRNA shots or two viral vector shots. “When you are getting such good data then we also need to be very flexible about mix and match. In fact, it is very good for us because then you’re not so dependent on the production of that particular vaccine,” believes Shaw.

mRNA vaccines carry the virus’ genetic code that generates the spike protein, prompting the body’s active immune cells to make antibodies to attack the spike. Thus, in the event of a person getting infected by SARS-CoV-2—the virus which causes Covid-19—the immune system will ward it off effectively. Unlike conventional vaccines, viral vector vaccines don’t contain antigens and, instead, use the body’s own cells to produce them.

Shaw’s comments have been seconded by the World Health Organization's (WHO) chief scientist, Soumya Swaminathan, who says India could initiate research on such a study. However, the scientist had also cautioned against the exercise, terming it a "dangerous trend" in the absence of more data on its health impact. In an online press briefing on July 13 at Geneva, Swaminathan said mixing is a "data-free zone" and it would be a chaotic situation if citizens were to decide “when and who will be taking a second, a third, and a fourth dose." She urged that the mix-and-match formula can only be initiated after material research is done in this regard.

By August-September, Shaw expects India to have a wider bouquet of vaccines, with the addition of Moderna, Pfizer, Johnson & Johnson, and Zydus Cadila. “In the next two months you will get 150 million doses, or a little more than that. I’m looking at 200 million doses by September per month. So, I think by the end of the year, if you can actually vaccinate 80% of the adult population, I think we will be in a very safe space,” says Shaw.

In fact, Shaw believes India, too, should actively engage in mix-and-match trials once more vaccine options are available. “There is already data available on the combination of the AstraZeneca and the mRNA vaccines. But, in India, we also need to do these trials because we have these different variants coming up. We could do trials on a Sputnik and Zydus Cadila vaccine, or a Covishield and Moderna vaccine, or a Covishield and Sputnik vaccine. There are a lot of opportunities for us to do many, many trials to see if we can get a better response.”

In May, the Covid-19 working group under the National Technical Advisory Group on Immunisation had said that India will soon start testing the mix-and-match approach to Covid-19 vaccines. In fact, a small batch of 20 people in Uttar Pradesh’s Siddharthnagar district were administered Covishield as their first dose and Covaxin as their second one. But, according to media reports, that was not a planned exercise but an inadvertent mix-up. However, in June, Dr. Randeep Guleria, chief of the All India Institute of Medical Sciences, too, went on record in an television interview stating that mixing of two Coronavirus vaccine shots can be a "possibility" as it can improve the immunity of a person against different virus variants, though more research is needed on this before a final decision could be taken.

Shaw believes that is the need of the hour.

“If you want to be smart—optimising your vaccine usage and vaccination pace—then you shouldn’t put yourself into a straight-jacket, and only allow people to receive only that vaccine as a second shot. Those are some of the smart thinking ideas we need to look at. I think mix-and-match is a very important part of the way forward,” argues Shaw.

Interestingly, the WHO’s Strategic Advisory Group of Experts on vaccines in June had stated that Pfizer’s vaccine could be used if the second dose of AstraZeneca is not available. Clinical trials mixing AstraZeneca and Pfizer as well as Moderna and Novovax vaccines are underway, led by the University of Oxford. Unlike the U.S., Canada and a couple of other countries have already permitted Covid-19 vaccine interchangeability based on trials such as the CoM-Cov randomised clinical trial in the U.K., the CombiVacS trial in Spain, and an observational study of 326 healthcare workers.

Russia is expected to release the results of Sputnik V and Astra-Zeneca mix-and-match vaccine at the end of July. Kirill Dmitriev, CEO, Russian Direct Investment Fund, was quoted as saying that it was open to mix-and-match with Covishield in India as it is the same vaccine as AstraZeneca’s. “We hope that the Serum Institute of India can produce Sputnik V and mix-and-match as well. It will be a true partnership,” Dmitriev had said.

Besides, mix-and-match, the Biocon chief feels that India should also look at the option of booster shots, especially given that there is no clarity on the long lasting efficacy of the vaccine. Shaw says, “That’s where the ICMR (Indian Council of Medical Research) should focus its efforts on garnering that data, on generating that data and doing the meaningful studies we need to do to generate that data.”

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