A health worker administers a COVID-19 vaccine to an elderly person at a hospital in Prayagraj, December 2, 2021. Photo: PTI
- A week after saying in its bulletin that booster doses should be ‘considered’, INSACOG now says this was neither a recommendation nor a suggestion.
- The consortium of laboratories set up by the Union health ministry was the first official Indian body to suggest a third dose of COVID-19 vaccines.
- In this week’s bulletin, INSACOG said population-level evidence suggests that the omicron variant is associated with substantial ability to evade immunity from prior infection.
New Delhi: A week after it said booster doses of the COVID-19 vaccine should be considered for certain at-risk groups, the consortium of laboratories set up by the Union health ministry on Saturday backtracked, saying it was merely raising a point of discussion and had not made any recommendation or suggestion for a third dose.
The Indian SARS-COV-2 Genome Consortium (INSACOG), a consortium of 28 national laboratories to monitor the genomic variations in the novel coronavirus, was the first official Indian body to say that booster doses should be ‘considered’ in its bulletin dated November 29. The consortium raised the topic while discussing the possibility that the omicron variant could escape immunity.
To quote last week’s bulletin, this is what INSACOG said about booster doses:
“Vaccination of all remaining unvaccinated at-risk people and consideration of a booster dose for those 40 years of age and over, first targeting the most high-risk / high-exposure may be considered, since low levels of neutralising antibodies from current vaccines are unlikely to be sufficient to neutralise Omicron, although risk of severe disease is still likely to be reduced.”
In the subsequent weekly bulletin, dated December 4, INSACOG said that “many more scientific experiments are needed” to assess the impacts of a booster dose. It is the mandate of the National Technical Advisory Group on Immunisation (NTAGI) and the National Expert Group on Vaccine Administration for COVID-19 (NEGVAC) to make recommendations and suggestions regarding vaccines, the consortium said in the bulletin.
On the ‘consideration’ that it suggested in the previous bulletin, INSACOG said that in view of the “emerging evidence from South Africa and some other countries” about omicron’s “substantial ability to evade immunity from previous infection”, there was a discussion about the “potential role of [an] additional dose of the COVID-19 vaccines in high-risk populations”.
“However, this was not a recommendation or suggestion for [a] booster dose in the national immunisation program. Immunity and protection from SARS-CoV-2 [are] multifactorial with several unknown factors and further compounded by emerging [variants of concerns],” the latest bulletin said.
After INSACOG’s bulletin had suggested that booster doses should be ‘considered’, the health ministry issued an FAQ about omicron, saying there is no reason yet to believe that vaccines are less effective against the new variant. The ministry also wanted more evidence, saying, “[D]efinitive evidence for increased remission and immune evasion is awaited.”
The ministry said while some of the mutations reported on the spike gene of the omicron variant may decrease the efficacy of existing vaccines, it added, “[V]accine protection is also by antibodies as well as by cellular immunity, which is expected to be relatively better preserved.”
‘Data suggests omicron has high infectivity’
The bulletin also noted that delta and its sublineages continue to be the main variant of concern globally, though omicron has appeared in more than 35 countries, “with rapidly growing outbreaks in Southern Africa”.
“The data available [for omicron] so far suggests high infectivity, possibly greater than delta. Reinfection risk estimated by epidemiologic surveillance system is greater than previously seen with either Beta or Delta variants,” INSACOG said.
Population-level evidence thus suggests that the omicron variant is associated with substantial ability to evade immunity from prior infection and transmit rapidly in populations with high levels of naturally acquired immunity, the bulletin said. “The degree by which omicron would be able to evade vaccine-induced immunity is not known yet. There is insufficient data to determine whether disease severity is different from previous variants, but rising hospitalisations in affected regions suggest that it would be premature to consider it less virulent,” the consortium noted.