According to a study published in The Lancet journal, it has been found that the Delta variant of coronavirus that was first identified in India, doubles the risk of hospitalisation compared with the Alpha variant that was first found in the UK, but Pfizer and AstraZeneca vaccines provide good protection against the strain.
The Pfizer-BioNTech vaccine provided better protection against the Delta variant as compared to the Oxford-AstraZeneca vaccine that is also known as Covishield in India, found the researchers at the Public Health Scotland and the University of Edinburgh, UK.
The period from April 1 to June 6, 2021 was analysis was done for the demographic distribution of cases. Around 19,543 confirmed cases of SARS-CoV-2 infections over the period of interest has been analysed by the team, out of whom 377 were admitted to hospital for COVID-19 in Scotland.
It was further found in the study that the Pfizer vaccine offered 92 per cent protection against the Alpha variant and 79 per cent against the Delta strain two weeks after the second dose. Around 7,723 community cases, 134 hospitalisations were found to have the Delta variant of coronavirus just two weeks after the second dose.
For AstraZeneca’s vaccine, there was 60 per cent protection against Delta compared with 73 per cent for Alpha variant, the researchers said. They also found that two doses of vaccine provide much better protection against the Delta variant compared to a single dose.
“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 risk of admission particularly increased in those with five or more relevant comorbidities,” the authors of the study noted.
“Both the Oxford–AstraZeneca and Pfizer–BioNTech COVID-19 vaccines were effective in reducing the risk of SARS-CoV-2 infection and COVID-19 hospitalisation in people with the Delta VOC,” they said.
However, it was noted by the researchers that these effects on infection with Delta variant appeared to be diminished when compared to those with the Alpha VOC.
But it was cautioned by the authors of the study that the vaccine comparison should be interpreted with warning due to differences in the groups which received each type of vaccine, and also in how quickly immunity is developed with each shot.
