Mix-and-match vaccines highly effective against Covid-19: Lancet study

People who received a first dose of the Oxford-AstraZeneca COVID-19 vaccine followed by an mRNA vaccine shot had a lower risk of infection compared to those immunised with both doses of the AstraZeneca preventive, according to a nationwide study in Sweden. The study, published in The Lancet Regional Health - Europe journal on Monday , October 18, 2021, is based on nationwide registry data from the Public Health Agency of Sweden, the National Board of Health and Welfare, and Statistics Sweden. In the main analysis, about 700,000 individuals were included. During a 2.5-month average follow-up period after the second dose, the study showed a 67 per cent lower risk of infection for the combination of AstraZeneca and Pfizer vaccine shots. There was a 79 per cent lower risk of infection for AstraZeneca and Moderna vaccine shots, compared to unvaccinated individuals, the researchers said. However, it has been unclear to which extent these schedules may reduce the risk of clinical infection, the researchers said, adding that their study aimed to fill that knowledge gap. On Oct 26, The WHO's technical advisory group will meet to consider the emergency use listing of India's Covaxin which is being used in the country's nationwide anti-COVID-19 vaccination programme, according to the global health agency's chief scientist Soumya Swaminathan.