Explainer: What you need to know about Covid AY.4.2 variant

What is the AY.4.2 variant?

Viruses constantly mutate. And the same is the case with SARS-CoV-2, the novel coronavirus that causes Covid-19. The AY.4.2 is a sub-lineage of the Delta variant of the SARS-Co-V-2 virus, or B.1.617.2. This sub-lineage contains two mutations in its spike protein. The UK Health Security Agency (UKHSA) has given the Delta sub-lineage AY.4.2 the official name VUI-21OCT-01. Delta, first identified in India in October 2020, was the cause for the surge in cases and deaths in India earlier this year.

Should we be worried about this variant?

It’s early days yet. According to the UK Health Security Agency (formerly Public Health England), the proportion of AY.4.2 continues to slowly grow. As of now, there is no biological basis for increased transmissibility of AY.4.2, as judged epidemiologically, and further examination is going on. Nevertheless, Delta variants with immune escape mutations are being tracked by the agency.

An early warning system for variants

Further, it adds, this sub-lineage accounted for approximately 6 per cent of all sequences generated, on an increasing trajectory. Further assessment is underway.

Are vaccines effective against AY.4.2?

The INSACOG weekly bulletin says vaccine effectiveness does not seem to be different for AY.4.2, compared to other Delta variants. INSACOG is a consortium of 28 National Laboratories in India to monitor the genomic variations in the SARS-CoV-2.

Delta variant not different among vaccinated and unvaccinated in Chennai: ICMR

Has WHO or the Indian government called it a variant of concern?

AY.4.2 frequency in India is too low to be a variant of concern at this point in time. It is less than 0.1 per cent of all the variants of concern (VOC) or variant of Interest (VOI), as per INSACOG.

Which is the most virulent variant of Covid so far?

Delta is the most contagious among all the variants so far. It is considered a “variant of concern” by the WHO and CDC (US Centers for Disease Control and Prevention) because it appears to be more easily transmitted from one person to another.

Will AY.4.2 become a VOC later?

Scientists of the Indian Council of Medical Research (ICMR) say it is difficult to determine whether the AY.4.2 is highly transmissible but it can be contained by following Covid-appropriate behaviour.

Do we need to do something different to protect ourselves from this variant?

The CDC says vaccination is the best way to protect oneself. High vaccination coverage will reduce spread of the virus and help prevent new variants from emerging. And of course, Covid-appropriate behaviour, including masking, social distancing and hand-washing, needs to be scrupulously followed.