The Pfizer coronavirus vaccine is 88 per cent effective against the Indian variant after two doses, a study by Public Health England has found.
Both the Pfizer and AstraZeneca jabs were found to be almost as effective against symptomatic disease from the B1617.2 strain as they are against the Kent variant after the second dose.
However, they were only 33 per cent effective three weeks after the first dose.
UK Health Secretary Matt Hancock described the outcome as "groundbreaking", while PHE said it expected to see even higher levels of effectiveness against hospital admission and death.
The study, which took place between April 5 and May 16, found that the Pfizer vaccine was 88 per cent effective against symptomatic disease from the Indian variant two weeks after the second dose, compared with 93 per cent effectiveness against the Kent strain.
Meanwhile, the AstraZeneca jab was 60 per cent effective, compared with 66 per cent against the Kent variant over the same period.
Both vaccines were 33 per cent effective against symptomatic disease from the Indian variant three weeks after the first dose, compared with about 50 per cent against the Kent strain.
Some 12,675 genome-sequenced cases were included in the analysis, but only 1054 were of the Indian variant.
The study included data for all age groups from April 5 to cover the period since the strain emerged.
Dr Jamie Lopez Bernal, consultant medical epidemiologist at PHE and the study's lead author, said there was more confidence in the data from the first vaccine dose compared with that from the second.
He told journalists on Saturday: "There are bigger numbers that have been vaccinated with one dose. So I think we classify that as moderate certainty around the first dose, but low levels of confidence around the second dose."
However, Professor Susan Hopkins, PHE's COVID-19 strategic response director, said the data trend was "quite clear" and was heading in the "right direction".
PHE said the difference in the effectiveness between the vaccines may be due to the AstraZeneca second dose being rolled out later than the Pfizer vaccine.
Data also shows it takes longer for the AstraZeneca jab to reach maximum effectiveness.
There were insufficient cases and follow-up periods to estimate vaccine effectiveness against severe outcomes from the Indian variant but this would be evaluated in the coming weeks, PHE said.
Australian Associated Press
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