Oxford says COVID-19 shot 76% effective after one dose for 3 months

The COVID-19 vaccine developed by Oxford University and AstraZeneca has 76% efficacy against symptomatic infection for three months after a single dose, with efficacy improving when a second shot is given later, a preprint study showed on Tuesday.

Oxford University said the findings supported a decision made by Britain to extend the interval between initial doses and booster doses of the shot to 12 weeks.