Delta variant may elude antibodies in vaccinated or previously infected persons: Study

The mutations specific to the much-feared Delta variant of the Covid-19 virus make it more difficult for the human body to identify and attack it, raising concerns that it might slip past the immune system of a vaccinated or a previously infected person, research suggests.

A study conducted by researchers at Gujarat Biotechnology Research Centre (GBRC) has shown that the new variant was more likely to evade the body’s immune system because it did not match the copy of the virus that the antibodies had been primed to fight, which could lead to “higher transmissibility, pathogenicity and virulence”.

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The Delta variant, flagged as a virus of concern (VOC) by the World Health Organisation (WHO) due to its higher transmissibility, is driving the pandemic in the UK, and has been detected in the US, Australia and Singapore.

Certain key mutations in the Delta variant, especially in the spike protein that antibodies latch on to, may explain why people who have already been infected by the disease or taken vaccine shots could be reinfected,.

The spike protein, which is the most susceptible to changes, appears to be more rigid as compared to the original “wild-type” Covid strain that emerged out of China’s Wuhan in 2019. It does not bind as well with the Delta variant of the virus, according to the computer simulation.

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A Public Health England study showed last month that a single shot of the Pfizer-BioNTech vaccine or the Oxford-AstraZeneca vaccine gave the recipient 33 per cent protection against the Delta variant, which increases further after the second dose. Most health experts agree that vaccines still provide protection against the variant, albeit to a lesser degree.

Researchers have advised to better monitor the virus through genome sequencing and surveillance even as India has so far lagged in its efforts. Genome sequencing could help determine the true extent of the virus’s spread and also keep tabs on crucial mutations in the virus that could make it far more deadly.