‘BA4, BA5 Omicron variants evading immunity’

Hyderabad: Clear signs have emerged from the ongoing surge of Covid-19 infections in Telangana and across other States that the BA4 and BA5 variants of Omicron are managing to escape immunity gained either by prior infection or through vaccines, health officials here believe. A large number of reinfections in Telangana, especially in the the urban […]

Hyderabad: Clear signs have emerged from the ongoing surge of Covid-19 infections in Telangana and across other States that the BA4 and BA5 variants of Omicron are managing to escape immunity gained either by prior infection or through vaccines, health officials here believe.

A large number of reinfections in Telangana, especially in the the urban areas under the GHMC limits, Medchal-Malkajgiri and Rangareddy, which had already endured three Covid waves in the past, is a clear indication that both the sub-variants are able to escape immunity.

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Among the community of public health experts, geneticists and epidemiologists, who have been tracking the behaviour of the new variants of Omicron, it is believed that due to the L452R mutation in the spike protein in BA5, the sub-variant is managing to escape immunity.

On June 22, researchers from Harvard University published a paper in the New England Journal of Medicine (NEJM) highlighting the ability of BA4 and BA5 to escape past immunity. “BA4 and BA5 substantially escape neutralising antibodies induced by both vaccination and infection. Our findings provide immunologic context for the current surges caused by the BA.2.12.1, BA4 and BA5 sub-variants in populations with high frequencies of vaccination and BA1 or BA2 infections,” researchers in the NEJM paper said.

Noted senior scientist from the CSIR-Institute of Genomics and Integrative Biology (IGIB) Dr Vinod Scaria took to Twitter on Sunday to highlight the impact of BA5. “We must consider that prior immunity is likely not protective. Covid pandemic displaying almost cyclical nature of waves of infection, in the past and also expected in future,” Dr Scaria said.

So, what are the options left to avoid getting reinfections? “We have clearly issued an advisory urging people to wear masks without fail while venturing out. High-risk individuals, including children below 10 years and above 60 years, must not venture out for a few days to avoid infection,” Director of Public Health (DPH), Telangana, Dr G Srinivasa Rao said.

Among other Non-Pharmaceutical Interventions (NPIs), Dr Scaria highlighted the need to have proper ventilation. “Even small efforts to improve ventilation could significantly reduce the risk of infections. Places where crowding is unavoidable and ventilation is not effective, air filters could be mandated, as in halls, malls, etc,” he tweeted.