Posted in Web New study finds Pfizer, AstraZeneca vaccines have lower … October 12, 2021 A new Oxford-led study has revealed that the efficacy of the Pfizer or the AstraZeneca vaccine in preventing infections slipped to 75 per cent and 61 per cent respectively 90 days after the second shot of the vaccines. https://www.indiatoday.in/coronavirus-outbreak/vaccine-updates/story/efficacy-pfizer-astra-zaneca-vaccines-delta-variant-covid-wanes-90-days-uk-study-1842770-2021-08-19