1 min read.Updated: 13 Aug 2021, 08:15 PM ISTLivemint
The efficacy of this approach has not been proven in field trials involving thousands of participants, Cyrus Poonawalla said
Dr Cyrus Poonawalla, Serum Institute of India (SII) chairman, today said that he was not in favour of administering two different Covid-19 vaccines for better efficacy. Mixing doses of two Covid-19 vaccines is "very wrong", the SII chairman said.
Poonawalla, whose firm makes the Covishield vaccine, was speaking to reporters after receiving the Lokmanya Tilak National Award in Pune.
"I am against the mixing of two different vaccines. There is no need to mix two different vaccines," Poonawalla said, when asked about a recent ICMR study that a cocktail of Covishield and Covaxin could generate better immunity.
"If cocktail vaccines are administered and if the result is not good, then SII may say that another vaccine was not good, vice versa, the other company might say that since you mixed Serum's vaccine, it did not give desired results," Poonawalla said.
This comment comes days after the Drugs Controller General of India approved a proposal to conduct a study on mixing Covaxin and Covishield vaccines in India. The study, involving 300 health individuals, will be carried out by Christian Medical College, Vellore.
The efficacy of this approach has not been proven in field trials involving thousands of participants, he added.
Clarifying his earlier statement, the SII chairman said, "For those who have been administered the first dose of a particular vaccine and incase of the unavailability of the second dose of the same - as an alternative, another vaccine can be administered. That said, the efficacy and the immunogenicity of the combination are dependent on the ongoing studies conducted by regulators."
A study by the Indian Council of Medical Research involving 98 people, 18 of whom had inadvertently received Covishield as first dose and Covaxin as the second in Uttar Pradesh, showed that combining vaccines elicited better immunogenicity.