A new study led by Public Health England found that two doses of either the the AstraZeneca
Conducted between nearly six weeks from April to May, researchers found that the mRNA vaccine developed by Pfizer and BioNTech was 88% effective against symptomatic disease for the B.1.617.2 variant--a strain of the variant that was first discovered in India--two weeks after the second dose, compared to 93% effectiveness against the B.1.1.7 variant that first emerged in the United Kingdom.
For AstraZeneca, the study found that two doses of the vector vaccine wer 60% effective against symptomatic disease for the India variant, compared to 66% effectiveness against the U.K. strain.
The study's authors noted that it is likely that vaccine effectiveness "against more severe disease outcomes" for both vaccines will be greater, and that they expect to see "even higher levels of effectiveness against hospitalisation and death." The researchers concluded that their findings supported two dose vaccine regimes for vulnerable populations in order to combat the circulation of the B.1.617.2 variant strain.
Despite the positive results for two doses of either vaccines, researchers found that both vaccines were only 33% effective against symptomatic disease from the India variant three weeks after the first dose, compared to being 50% effective against the U.K. strain in the same time period.
The study analyzed data from more than 1,000 participants who were confirmed as having the B.1.617.2 variant through genomic sequencing, with volunteers including a range of age groups and several ethnicities.
The results of the study were published on Saturday as a preprint and the study had yet to be peer-reviewed.
The variant first discovered in India has been blamed for causing a devastating third wave of COVID infections in the country, which has overwhelmed India's health care system and led to high fatality rates in the past few weeks. As the new highly infectious emerging strain begins to crop up in countries all around the world, global health authorities are concerned that developed vaccines will not provide the same level of protection as they do against the original strain of the SARS-CoV-2 virus.
"We can now be confident that over 20 million people--more than 1 in 3--have significant protection against this new variant, and that number is growing by the hundreds of thousands every single day as more and more people get that vital second dose," said Matt Hancock, U.K. Health and Social Care Secretary, in a press release. "It's clear how important the second dose is to secure the strongest possible protection against COVID-19 and its variants."