New Delhi: The government may reduce the gap between the two doses of the Covishield vaccine for those 45 years and older. The decision may be taken in two to four weeks, COVID-19 working group chairman Dr NK Arora was quoted as saying by Mint. The decision will be based on final scientific evidence.
Initially, the gap between two doses of Covishield was 4 to 6 weeks. It was then increased to 4 to 8 weeks and then finally, 12 to 16 weeks.
This increase 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, the report added.
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. Now, in India too, there are many studies on the effectiveness of the doses on the local population. “We have gathered data on the impact of vaccines and their dosage interval on different age groups and from different regions,” Dr NK Arora was quoted as saying.