COVID Working Group Chief Dr NK Arora revealed that, as per the research, Serum Institute's Covishield can provide 61% effectiveness against the Delta strain. The statement comes at a time when there has been a lot of talk regarding the gap between the two doses of Covishield vaccine.
Statistically significant data from Christian Medical College Vellore's research, based on a sample size of several thousand during the peak Delta variant or B.1.617 outbreak, showed that a single dose had a 61% vaccine effectiveness which increased to 65% with two.
The study, which is yet to be peer-reviewed, involves observations made on 8,991, or 84.8% of its staff members who received the Covishield vaccine, while the remaining were administered Covaxin.
The Delta variant of COVID-19 was first identified in India and is known to double the risk of hospitalisation. It has also been largely attributed to the sudden and massive explosion of COVID-19 cases in India during the second wave.
Besides the vaccine efficacy quoted by Arora, the study also showed that one dose of the Covishield shot reduced the risk of hospitalisation by 70% and two doses by 77%. Dr NK Arora also added that data from the Chandigarh hospital showed 75% efficacy of Covishield against the Delta variant.
Prior to this, a Lancet journal had found that Pfizer and AstraZeneca vaccines provided good protection against the strain.
Meanwhile, the Union Health Ministry dismissed media reports claiming there was dissent from technical experts about increasing the gap between two Covishield doses and said the decision was based on scientific reason.
Reuters had previously quoted three scientists, including the former chief of the government-run National Institute of Epidemiology, as saying that they had only discussed increasing the interval to eight-12 weeks and not 12-16 weeks.
