WORLDAstraZeneca COVID-19 Vaccine 76 Per Cent Effective in Updated US TrailNileshMarch 25, 2021April 8, 2021 by NileshMarch 25, 2021April 8, 202101111 AstraZeneca said its COVID-19 vaccine was 76 per cent effective at preventing symptomatic illness in a new analysis of its major US trial a tad...