That headline is not quite correct. From the article: > Phase 3 interim analysis including 131 Covid-19 cases indicates that the vaccine is [on average] 70.4%

That headline is not quite correct. From the article: > Phase 3 interim analysis including 131 Covid-19 cases indicates that the vaccine is [on average] 70.4% effective when combining data from two dosing regimens ... In the two different dose regimens vaccine efficacy was 90% in one and 62% in the other And to be clear, it's not just one dose vs two: > tests on two different dose regimens showing that the vaccine was 90% effective if administered at a half dose and then at a full dose, or 62% effective if administered in two full doses. So "Oxford vaccine is up to 90% effective", perhaps?