Researchers call for rapid worldwide inoculation of unvaccinated population2 doses best bet against Delta: Oxford
Aditi Tandon
Tribune News Service
New Delhi, August 19
Getting two vaccine doses remains the most effective way to ensure protection against the Delta variant of concern dominant in the UK and India today and present in 148 countries, according to a study from the University of Oxford.
Published as a pre-print today, the study found that with Delta, Pfizer-BioNTech and Oxford-AstraZeneca vaccines still offered good protection against new infections, but effectiveness was reduced compared with Alpha. Researchers analysed 25,80,021 test results from over 3,80,000 participants.
People, who had been vaccinated after already being infected, had even more protection than vaccinated individuals who had not had Covid before. However, Delta infections after two vaccine doses had similar peak levels of virus to those in unvaccinated people; with the Alpha variant, peak virus levels in those infected post-vaccination were much lower.
Professor Sarah Walker of University of Oxford and Chief Investigator for the Covid-19 Infection Survey, said: “We don’t yet know how much transmission can happen from people who get Covid after being vaccinated but the fact that they can have high levels of virus suggests that people who aren’t yet vaccinated may not be as protected from the Delta variant as we hoped. This means it is essential for as many people as possible to get vaccinated — both in the UK and worldwide.”
This study from the Covid-19 Infection Survey is the largest to evaluate, and directly compare the real-world effectiveness of the Pfizer-BioNTech and Oxford-AstraZeneca vaccines against all infections, including those without symptoms, after the Delta variant has dominated.
