Omicron threat in India: Insacog recommends booster dose for above 40

The Indian SARS-CoV-2 Genomics Consortium, Insacog, has suggested booster shots of the Covid-19 vaccine for those above 40 years to deal with the threat of the Omicron variant. Insacog is a consortium of 28 laboratories that monitors genomic variations in coronavirus.

Insacog’s weekly bulletin suggested vaccination of all remaining unvaccinated at-risk people and considering a booster dose for those 40 years of age and over. Booster doses should first target the most high-risk/high-exposure segment as the low levels of neutralising antibodies from current vaccines was unlikely to be sufficient to neutralise Omicron, Insacog said.

The US and Britain have already cleared booster shots for some age groups. Union health minister, Mansukh Mandaviya, said in Parliament on Friday that decision on booster doses and Covid-19 vaccine dose for children was not a political decision and would be taken by expert group of scientists based on science. The minister said as part of the new travel guidelines, RT-PCR tests were conducted on all 16,000 travellers coming to India on 58 flights from at-risk countries and 18 Covid positive cases have been detected. These 18 Covid positive cases have been sent to Insacog for genomic sequencing to check for the Omicron variant, the minister said.

Booster doses has been suggested as Omicron is a heavily mutated variant that is predicted to be able to evade prior immunity from natural infections or from vaccines. Preliminary evidence suggests that Omicron may increase reinfection risk, which is expected from the structural changes due to the mutations, and the number of cases of this variant appears to be increasing in almost all provinces in South Africa, Insacog said. A fair and effective strategy for detecting and containing entry of Omicron into India is being implemented, since based on the preliminary data, it is likely that population immunity and vaccine-induced immunity may not sufficiently block its propagation, Insacog said.

According to Insacog, genomic surveillance would be critical for early detection of the presence of this variant, to enable necessary public health measures. Monitoring travel to and from the known affected areas and contact tracing of Covid-19 cases with an epidemiological link to the affected areas has been implemented along with increased testing with sequencing of confirmed cases, Insacog said.

The state surveillance programme of Karnataka is investigating the two reported outbreaks in the state. The first two cases of Omicron has been detected in Karnataka – a 46-year-old fully vaccinated doctor from Bengaluru with no travel history and a 66-year-old South African national.