Covishield dose gap may again be reduced, but only for people above 45

The government may again reduce the gap between the two doses of the Covishield vaccine, but this time it will only be for those 45 years and older, according to a Mint report.

The decision may be taken in two to four weeks, Covid-19 working group chairman Dr NK Arora has said in an interview. The decision will be based on final scientific evidence.

The present gap between the doses of Covishield is 12 to 16 weeks for all adults. At the very beginning of the vaccination drive in India, the recommended gap between the two doses of Covishield was 4-6 weeks, which was increased to 4 to 8 weeks and then finally to 12 to 16 weeks.

The decision to increase the gap to 12 to 16 weeks met criticism as the move was interpreted as an attempt to manage the vaccine scarcity in the country at that time.

Experts, however, asserted that the decision was based on the emerging international scientific studies, according to which a longer gap between the doses generated more antibodies.

In these studies, it was found that the percentage of antibodies produced by the first shot of the vaccine is quite high. Hence, the next shot should be delayed allowing the first shot more time to work.

But soon after, India increased the gap between the two doses in June, new studies claimed that the effectiveness of the first shot of Covishield was overestimated earlier.

This again followed a reduction in the gap of the two doses of Covishield in many countries. Indian experts have reiterated that the vaccination situation is dynamic and will change as new studies will emerge, but public health will get paramount importance in whatever decision is taken.

As Covishield is the same as the Oxford-AstraZeneca vaccine, international studies are available regarding the efficacy of each dose.