Variants V Vaccine

How the entry of the new variants impacts the global efforts to curb the pandemic

- Vibha Varshney

THE WAR against covid-19 pandemic has lately got complicated. Three worrisome variants of sars-cov-2 are circulating the world. These are the UK variant, the South Africa variant and the Brazil variant. On February 23, Vinod Paul, member (health), niti Aayog, said at a press conference India has identified one case of the Brazil variant, six cases of the South African variant and 187 people infected by the UK variant. The UK variant is 35 to 75 per cent more transmissible than the original Wuhan virus and results in a 30 per cent higher rate of mortality. Similarly, the Brazil and South Africa variants seem to have a higher propensity for causing re-infection along with being more transmissible (see 'Killer mutants', p18). India has also reported two indigenous variants in Maharashtra. Paul says the Indian variants cannot be blamed for the current surge of cases in the state as of now.

However, the five new variants are a cause for concern as they are the result of mutations in the virus's spike proteins, which have been used to develop covid-19 vaccines. Spike proteins work as antigens that elicit the immune response either in the people who get infected or those who receive the vaccine. “The worry is whether the immunity against the previous variant protects against the mutated variants,” says T Jacob John, a virologist based in Vellore, Tamil Nadu. If the antigen has “drifted” (changed due to small changes or mutations in the genes of the virus), the immunity induced by an infection or by a current vaccine may not match the drifted virus variant, he explains.