The vaccines were also found to give a similar level of protection against symptomatic disease from the UK variant (B117), the BBC reported on Sunday. 

The study, led by Public Health England (PHE), showed that three weeks after the first dose, both vaccines provided only 33 per cent protection against the Indian variant, while it offered 50 per cent effectiveness against the UK variant. 

The Covid jabs by Pfizer and AstraZeneca are likely to be even more effective at preventing hospital admission and deaths, the researchers said. 

For the study, a total of 12,675 sequenced cases were included between April 5 and  May 16. Of these, B117 was detected from 11,621 cases and B16172 from 1,054. 

The Pfizer vaccine was found to be 88 per cent effective at stopping symptomatic disease from the Indian variant two weeks after the second dose, compared with 93 per cent effectiveness against the UK variant. 

On the other hand, the AstraZeneca jab was 60 per cent effective against the Indian variant, compared with 66 per cent against the UK variant, the report said. 

The difference in effectiveness between the vaccines after two doses might be explained by the fact that rollout of second doses of AstraZeneca was later than for the Pfizer vaccine, which was approved first. Other data shows it takes longer to reach maximum effectiveness with the AstraZeneca vaccine, PHE said. 

The study looked at data from all age groups from April 5, to cover the period since the Indian variant emerged. There is not enough data to estimate how effective the vaccine is against severe outcomes for the Indian variant, PHE said. 

There was higher confidence in the data from the first vaccine dose than that from the second as "there are bigger numbers that have been vaccinated with one dose", Jamie Lopez Bernal, consultant medical epidemiologist at PHE and the study's lead author, was quoted as saying.