Pfizer, AstraZeneca vaccines protect against Delta variant, says study
Pfizer and AstraZeneca vaccines provide good protection against the Delta variant of coronavirus, first identified in India, says a study published in The Lancet Journal. Researchers at Public Health Scotland and the University of Edinburgh, UK, found that the Pfizer-BioNTech vaccine offered better protection against the Delta variant compared to the Oxford-AstraZeneca preventive, known as Covishield in India.
People and cases involved in the study
The analysis covered the period from April 1 to June 6, 2021, for the demographic distribution of cases. The team analyzed 19,543 confirmed SARS-CoV-2 infections over the period of interest, of whom 377 were admitted to hospital for COVID-19 in Scotland. Around 7,723 community cases and 134 hospitalizations were found to have the Delta variant of coronavirus.
Two doses of vaccine provide much better protection
The study found that the Pfizer vaccine offered 92 percent protection against the Alpha variant and 79 percent against the Delta strain two weeks after the second dose. For AstraZeneca's vaccine, there was 60 percent protection against Delta compared with 73 percent for the Alpha variant. They also found that two doses of vaccine provide much better protection against the Delta variant.
More cases of hospitalization reported in case of Delta variant
The risk of COVID-19 hospital admission was approximately doubled in those with the Delta variant of concern (VOC) when compared to the Alpha VOC, with the risk of admission particularly increased in those with five or more relevant comorbidities. Both the Oxford-AstraZeneca and Pfizer-BioNTech COVID-19 vaccines were effective in reducing the risk of SARS-CoV-2 infection and COVID-19 hospitalization in people with the Delta VOC.
Various factors come into play while comparing vaccines
However, the researchers noted that these effects on infection with the Delta variant appeared to be diminished when compared to those with the Alpha VOC. The authors of the study warned that the vaccine comparison should be interpreted with caution due to differences in the groups which received each type of vaccine and also in how quickly immunity is developed with each shot.