Delay 2nd dose for more efficacy: Experts

Delay 2nd dose for more efficacy: Experts

Nisha.Nambiar@timesgroup.com

Pune:12.03.2021 

Public health experts, citing emerging evidence, have said that India could consider delaying the second dose of the Covid vaccine to improve immunogenicity. Currently, the follow-up shot is being given 28 days later. Experts TOI spoke to said the country could look beyond that timeline.

Dr Gagandeep Kang, a member of Strategic Advisory Group of Experts (SAGE), which is advising the World Health Organization, said the decision to delay was not just about supply constraints, but improved efficacy too.

A recently published Lancet study said the Oxford-AstraZeneca vaccine — made in India by Serum Institute as Covishield — showed greater efficacy when its second dose was administered after a gap of 12 weeks, instead of four. The study was based on results from over 17,000 trial participants. The researchers found that efficacy of the shot had risen from an average of 55.1% (after two doses were given fewer than six weeks apart) to 81.3% when the interval was at least12 weeks.

Dr Lalit Kant, former head of ICMR’s Epidemiology and Communicable diseases division said models have shown a delayed second dose offers better protection, but real-world conditions can differ. “Delayed doses can protect a higher number of people quickly when supplies are limited. But in India, we don’t seem to have a shortage of vaccines. So the benefit is in terms of improving the level of protection.”

Dr Kant added, “A closer look at the Lancet study shows the sample size was too small to draw a meaningful conclusion. Therefore, studies with adequate sample sizes are needed before we can think of changing India’s vaccination schedule for Covishield.”

Covishield to cost less than ₹200/dose

The Indian government has lowered the price at which it buys AstraZeneca’s Covid-19 vaccine doses being produced by the Serum Institute of India (SII), the federal health secretary said on Thursday. “The renegotiated price is significantly lower than Rs 200 ($2.75) per dose,” health secretary Rajesh Bhushan said. The SII has licensed the vaccine from AstraZeneca and Oxford University and markets it as Covishield. REUTERS