Pfizer and AstraZeneca vaccines “highly effective” against Indian variant, according to new study

Public Health England (PHE) said on Saturday that the Pfizer/BioNTech vaccine was roughly 88% effective against symptomatic Covid-19 from the variant, two weeks after the second dose.

Meanwhile, the AstraZeneca vaccine was 60% effective against symptomatic disease caused by the variant.

The study found that for the period from 5 April to 16 May, the Pfizer-BioNTech vaccine was 88% effective against the B.1.617.2 variant two weeks after the second dose, compared to 93% effectiveness against the B.1.1.7 variant.

Two doses of the AstraZeneca vaccine was also found to be 60% effective against the B.1.617.2 variant compared to 66% effectiveness against the B.1.1.7 variant.

Both vaccines were found to be 33% effective against symptomatic disease from B.1.617.2, three weeks after the first dose compared to roughly 50% effectiveness against the B.1.1.7 variant.

Public Health England said that the difference may be explained by the fact that the rollout of second doses of AstraZeneca came after the Pfizer vaccine.

Researchers first discovered the new variant, with two new mutations which may be better at evading the immune system, in India.

In 15-20% of samples from the Indian state of Maharashtra (the state accounting for 62% of cases in the country), a new, double mutation in key areas of the virus had been detected.

The double mutation is concerning because it is located in the spike protein of the virus, which is the part it uses to penetrate human cells.

Spike proteins attach via receptor binding domains, meaning the virus can attach to receptors in our cells. However, the newer mutations include changes to the spike protein that make it fit better to human cells, an issue as it means the virus can gain entry into the cells easier and multiply faster.