Tests on mixed vaccines may start in a few weeks

[Rohan Tiwadi]

The testing may be carried out both using vaccines that are currently available in the country, and those that are in the pipeline.

India may soon begin testing the feasibility of a regimen that mixes two different Covid-19 vaccines to see if it helps boost immune response to the virus.

The testing may be carried out both using vaccines that are currently available in the country, and those that are in the pipeline, The Indian Express has learnt.

Work is expected to begin “in a few weeks”, according to Dr N K Arora, chairman of the Covid-19 working group under the National Technical Advisory Group on Immunization (NTAGI).
Approximately eight vaccines may be mixed and matched as part of the process, Dr Arora said. These include the three vaccines that are currently approved for use in the country, Serum Institute of India’s Covishield, Bharat Biotech’s Covaxin, and the Russian made Sputnik V.

Clinical testing as part of the exercise may be carried out by collaboration between bodies like the Indian Council of Medical Research and the companies that developed and produced the vaccines. The tests will study factors such as whether vaccines based on different platforms can be given together, and which vaccines to administer in the first and second doses.

“We are looking for a combination of vaccines that provide better protection. At the moment, the vaccines used are providing protection against severe disease, but they are not providing protection from infection and transmission of the virus to the extent that we would have liked,” Dr Arora said.

“Various factors have to be considered here. Proper research studies in actual field conditions have to be done… The whole purpose is to have better immune protection for the population without any adverse effects,” he said.
“Both the vaccines individually would be safe, but the focus is also to see if they are safe together… These vaccines are produced in different platforms and we don’t want them to create difficulty and create complications, so every vaccine will probably not be possible to mix and match,” he added.

The mixing of Covid-19 vaccines has been discussed at the Covid-19 working group, NTAGI, and National Expert Group on Covid-19 Vaccine Administration (NEGVAC), it is learnt.

“These trials may be embedded in the country’s existing immunisation programme against Covid-19,” Dr Arora said. “Discussions over the feasibility and value of mixing of Covid-19 vaccines have been proposed at every level.”

There are currently six Covid-19 vaccines in the pipeline — Serum Institute’s Covovax, Biological E’s Corbevax, Zydus Cadila’s ZyCov-D, Gennova’s mRNA vaccine, Bio E’s version of the Johnson & Johnson vaccine, and Bharat Biotech’s intranasal Covid-19 vaccine. The government has been in discussions with Pfizer to bring its mRNA vaccine to the country this year.