Single dose of two-shot jabs barely works against Delta variant: Study
This new study offers more clarity on the efficacy of vaccines against the Delta variant, which has been found to be more contagious than its previous versions.
A new study has highlighted the importance of both shots of two-dose Pfizer-BioNTech and AstraZeneca (AZ) Covid-19 vaccines against the Delta variant. Researchers have found single shots of these vaccines “barely” offered any protection.
In India, AZ shots are being given under the Covishield brand, manufactured by the Serum Institute of India.
“Sera from individuals having received one dose of Pfizer or AstraZeneca vaccine barely inhibited variant Delta,” a group of French researchers said in an article published in journal Nature on Thursday. “Administration of two doses generated a neutralising response in 95% of individuals.”
The finding is “good news”, Olivier Schwartz, lead author of the study and head of the Virus and Immunity Unit at the Pasteur Institute in Paris, told The Washington Post.
This new study offers more clarity on the efficacy of vaccines against the Delta variant, which has been found to be more contagious than its previous versions and has caused maximum damage in India triggering the devastating second wave.
The findings are along similar lines as those of a study released by the Indian Council of Medical Research (ICMR) earlier this week, which said two doses of Covid-19 vaccines offer 95% protection against infection to 82% for those with only one shot.
Delta is now tearing through parts of the United States with low levels of vaccination. The US Centers for Disease Control and Prevention has said Delta has emerged as the dominant strain in America, accounting for 51.7% of new infections, overtaking Alpha.
The new study points to increased vulnerability to the Delta variant among people who have either not been vaccinated for whatever reason or who have skipped or delayed their second shots. In the United Kingdom, for instance, this variant was seen responsible for a recent surge because it opted to administer only one of the two shots of these vaccines to broaden coverage.