Virologists have called the Union Health Ministry’s decision to reduce the mandatory time interval between the second dose of the COVID vaccine and the third “precautionary dose” from nine months to six as ad hoc, stating that it appears to have been guided by economic rather than scientific considerations.
Noting that the Union government and the National Technical Advisory Group on Immunization (NTAGI) had chosen to call the third vaccine a “precautionary dose” rather than a booster dose, NTAGI member Dr. Jaiprakash Muliyil , said there was no science behind the decision to shorten the time interval.
“It’s the economy. We have many manufactured vaccines waiting to be sold, but the current vaccines work against the first variants of the coronavirus: alpha, beta, delta and gamma. The Omicron has almost eliminated the previous strains of Covid-19 and it is also rapidly evolving and mutating,” Muliyil said.
Dr. Vineeta Bal, a scientist at the National Institute of Immunology, said that no data-driven clinical trial had been conducted for Indian vaccines to determine whether a precautionary dose was better after a time interval of six months or nine. “So, let’s go through the history of virology. We know that a two-dose regimen will result in immunity and the infection will slowly subside,” he added.
The government probably decided to ask people to take the third dose earlier because there’s a new variant, he joked.
Earlier this week, an Israeli expert reported that a new sub-variant of Omicron BA.2.75, which may be of an “alarming” nature, had been detected in some 10 states in the country. However, the Ministry of Health has yet to confirm the presence of these variants in the country.
According to the Indian SARS-CoV-2 Genomics Consortium (INSACOG), the first confirmed case of the BA.4 Omicron variant in India was reported in Hyderabad in May this year.
There are different sublineages of the Omicron variant: BA.1, BA.2, BA.3, B.4, BA.5, BA.1.1, but BA.2 is the dominant variant worldwide due to its higher transmissibility.