India's new COVID-19 vaccine plan is to study mixing doses

"We have heard recently that Europe, Spain and the UK are also doing a study where two vaccines-- Covishield and Pfizer-- have been given on alternate days," said Dr N K Arora, Chairman of COVID-19 working group under NTAGI.

File Photo (Reuters)

New Delhi: Amid a shortage of vaccines, India plans to do a study on mixing COVID-19 doses and to ascertain its efficacy in boosting the immune response to coronavirus.

"India may in few weeks start testing the feasibility of a regimen that mixes two different doses of Covid vaccines to see if it helps boost the immune response to the virus," said Dr N K Arora, Chairman of COVID-19 working group under the National Technical Advisory Group on Immunisation (NTAGI).

"We have heard the news that in some states people have received a vaccine of a particular brand as the first dose and a different vaccine brand as second dose two due to programmatic error. This is a program error. It shouldn`t have happened and the frontline workers have been advised to be more careful but there are no safety concerns, these beneficiaries have been followed up, so there is nothing to be worried about," he said.

"We also heard that in Karnataka, several health professionals went on to ask for additional doses on top of their complete schedule of two doses as they were worried about immunity and effectiveness of the vaccines," he added.

Regarding the study on mixing COVID-19 doses, Dr Arora said, "We have heard recently that Europe, Spain and United Kingdom are also doing a study where two vaccines-- Covishield and Pfizer-- have been given on alternate days. Covishield as the first dose and the second dose of Pfizer or vice versa. This is called interchangeability studies."

"Two vaccines may be given in different orders for three purposes. One is that these become convenient programmatically, but more important is that it shouldn`t create any safety issues and the third is to ascertain if there is an immune advantage, whether the effectiveness of this mix and matching increases the protective efficacy of the vaccines. So, all these three things have to be taken care of simultaneously," he explained.

The mixing of the vaccine has been discussed at the COVID-19 group, NTAGI and National Expert group on COVID-19 Vaccine Administration (NEGVAC). 

Meanwhile, India`s daily COVID-19 cases continue to decline further as 1,52,734 fresh infections were recorded between Sunday and Monday morning. According to the Ministry of Health and Family Welfare, India reported the lowest single-day spike in over 50 days.