Covishield Dosage Interval: Based on Science or Vaccine Shortage?

This is the second time in 3 months that Covishield dosage intervals have been widened.

The Big Story Podcast on the extension of interval time between two Covishield doses. 

(Photo: The Quint)

Just seven weeks after it directed state governments to increase the gap between two doses of Covishield vaccines to 6-8 weeks, on 13 May, the Union Health Ministry once again announced a further extension of the gap to 12-16 weeks, citing “real-world evidence” in the United Kingdom on vaccine efficacy.

This recommendation was made by the National Expert Group on Vaccine Administration for Covishield only.

However, the decision comes at a time when the country is facing a severe shortage of vaccines – specifically Covishield, which has been used to inoculate the majority of the population so far.

The change in vaccine dosage policy has raised a lot of curiosity, with many many wondering if the decision is based on scientific data or is it meant to cover up the vaccine shortage in the country.

To decode the health ministry's decision and the scientific basis behind it, for today’s episode, we spoke to Dr Swapneil Parikh, a clinical researcher at Kasturba Hospital for Infectious Diseases, and Dr Chandrakant Lahariya, a vaccines, public policy and health systems expert.