The Pfizer coronavirus vaccine is 88 per cent effective against the Indian variant after two doses, a study by Public Health England (PHE) 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, UK variant after the second dose.
However, they were only 33 per cent effective three weeks after the first dose.
The study, which took place between April 5th and May 16th, 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 1,054 were of the Indian variant.
The study included data for all age groups from April 5th to cover the period since the strain emerged.
On Friday Ireland’s chief medical officer Dr Tony Holohan said the Indian variant of Covid-19 poses a threat to the progress made in suppressing the virus.
“For the most part, the sky is mostly blue but with a black cloud on the horizon which is the Indian variant,” Dr Holohan said.
Nphet was “genuinely concerned” about this variant, particularly in the light of new evidence from Public Health England suggesting vaccines may be less effective against it after a first dose, he said.
On Sunday Clíona Ní Cheallaigh, infectious disease consultant at St James’s Hospital, Dublin described the study as “pretty good news”.
“It has gone from a very big dark black to a cloud that is grey and in the distance it doesn’t look like the hurricane we thought that was coming,” she told the Brendan O’Connor Show on RTE radio.
Asked about the Indian variant of Covid-19 on Friday Taoiseach Micheál Martin said the Government was tracking it very closely and he had been briefed on it by the British prime minister Boris Johnson during their meeting last week.
He said 42 per cent of adults had their first dose of the vaccine and 15 per cent had received two doses. “That gives strong protection already in reducing severe illness. Our hospitalisation numbers are steady… It reflects the impact of vaccination.”
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 show it takes longer for the AstraZeneca jab to reach maximum effectiveness.
There are insufficient cases and follow-up periods to estimate vaccine effectiveness against severe outcomes from the Indian variant but this will be evaluated over the coming weeks, PHE added.–PA