RIO DE JANEIRO, BRAZIL - Two doses of Pfizer and AstraZeneca's Covid-19 vaccines are nearly as effective against the highly transmissible Delta variant of the coronavirus as against the previously dominant Alpha variant in several countries around the world, a study published Wednesday showed.
Officials say the vaccines are highly effective against the Delta variant, now the dominant strain in most of the world, although the study reiterated that one dose of the vaccines alone is not enough for high protection.
The study, published in the New England Journal of Medicine, confirms key findings provided by the British government . . .