Can I take a second dose of a different vaccine? The short answer is no. For the long answer, read on.
Currently, the Indian government says no to mixing Covaxin and Covishield, or any other vaccines. This is mostly because it has not been tested.
Experts, however, believe it could be possible in the future.
At the same time, the US, UK, Canada, Sweden, Finland, France and a few other nations have allowed mixing and matching of vaccines if the 2nd dose is not available. Canada, Finland, Norway and France allow a different 2nd dose if the first dose was AstraZeneca.
Dr Faheem Younus, the chief of infectious disease at the American University of Maryland Upper Chesapeake Health (UM UCH), wrote the following on Twitter.
He wrote, “Q: Can I take Pfizer/Astra Zeneca/JJ after getting vaccinated with Covaxin or Sinopharm etc? Can I mix and match vaccines?”
“As of today, I’d say no. It’s being studied. Besides rare exceptions don’t mix. This WILL change. Wait 2-3 months instead of taking a blind risk,” he answered.
Niti Aayog member VK Paul recently answered this question on similar lines as well. “It is plausible. But there need to be more studies. It can’t be said definitively that mixing of doses can be practised. There is no robust scientific evidence,” said Paul.
“Only time will tell whether it will be done in future or not, it will depend on international studies, World Health Organization findings etc. Our experts are also continuously studying,” he added.
Paul said, “One shot of one type [of Covid-19 vaccine] produces antibodies and the second shot from another will increase that. Scientifically, there is no problem.”
A trial with 600 people has shown that mixing doses of Pfizer and AstraZeneca (Covishield in India) vaccines has improved immune response with mild side-effects.
The UK is trying a combination of Pfizer, Moderna, AstraZeneca and Novavax vaccines. 2 doses will be given to 50 volunteers with a gap of 12 weeks.
China is also considering mixing COVID-19 vaccines made with different technologies.
As for India, there has been no study undertaken for Covishield and Covaxin. The third approved vaccine – Sputnik V, uses slightly different shots for its two-dose inoculation regime.
There have been no reported adverse effects of mixing Covishield and Covaxin, which happened by accident in UP. However, this is currently not recommended.
