A healthcare worker holds syringes of Moderna and Pfizer vaccines for coronavirus disease (COVID-19) at a vaccination center in El Paso, Texas on May 6, 2021.
Jose Luis Gonzalez | Reuters
A new study has found that two doses of the vaccine Pfizer-BioNTech or AstraZeneca-University of Oxford offer effective protection against the variant of Covid, which was first discovered in India. However, she underlined the need for two doses as both vaccines were significantly less effective after just one shot.
The study, led by Public Health England, also found that two doses of one of these vaccines were similarly effective against the variant, which first appeared in the UK and has since become a dominant strain in the West.
Dr. Jenny Harries, CEO of the UK Health Security Agency, told the BBC that the study provided “the first real evidence of vaccine effectiveness” against the variant first identified in India.
The research, conducted between April and May, found that the Pfizer BioNTech vaccine was 88% effective against symptomatic diseases from Covid variant B.1.617.2 – a subtype of a variant that appeared in India last fall and is itself has since spread across Europe. two weeks after the second dose. The vaccine was 93% effective against the B.1.1.7 variant two weeks after the second dose. which was first discovered in the UK last fall.
Meanwhile, two doses of the AstraZeneca vaccine have been found to be 60% effective against symptomatic disease from variant B.1.617.2 from India, compared with 66% against the strain from the UK
“The efficacy of the vaccine against symptomatic diseases from variant B.1.617.2 is similar after 2 doses compared to variant B.1.1.7 (Kent), which is predominant in Great Britain, and we expect an even higher efficacy against hospitalizations and deaths”, wrote the study’s authors. The results were published on Saturday as a preprint and the study has not yet been peer-reviewed.
PHE said the difference in effectiveness between the vaccines after two doses “can be explained by the fact that the introduction of the second doses of AstraZeneca came later than the Pfizer BioNTech vaccine, and other antibody profile data shows that it takes longer to achieve maximum effectiveness with the AstraZeneca vaccine. “
However, both vaccines were only 33% effective against symptomatic diseases from B.1.617.2 three weeks after the first dose. In the same period it was found that they are 50% effective compared to variant B.1.1.7.
First discovered in India, the variant has been accused of causing a dramatic third wave of infections in the country, overwhelming hospitals and causing thousands of deaths this spring. There have been concerns that the variant might make Covid vaccines less effective, so the latest data should help allay those worries.
According to the World Health Organization, which described it as a “worrying variant” at the beginning of May, the India variant has since been discovered in numerous other countries.
The PHE study analyzed data from 1,054 people of all ages and races who were confirmed by genomic sequencing to have variant B.1.617.2. The data was collected from April 5th, covering the period since variant B.1.617.2 (one of three variant subtypes found in India) appeared in parts of the UK
“As with other variants, an even higher level of efficacy against hospitalization and death is expected. There are currently not enough cases and follow-up periods to assess the effectiveness of the vaccine based on serious results from variant B.1.617.2. PHE will continue to evaluate this. ” in the coming weeks, “added the study’s authors.
In his response to the study, UK Health Secretary Matt Hancock described the results as “groundbreaking – and proves how valuable our Covid-19 vaccination program is in protecting the people we love.”
The UK has given two doses of a Covid vaccine to more than 22 million people, while 72% of the population (or nearly 40 million people) have received one shot, government data shows.
Hancock said the latest data emphasized “the importance of the second dose in ensuring the best possible protection against Covid-19 and its variants”.
A separate PHE analysis found that the country’s Covid-19 vaccination program has prevented 13,000 deaths and around 39,100 hospitalizations among elderly people in England by May 9.