Thread by @hildabast

Oh this is great news! 🥳

Oxford-AstraZeneca vaccine: 79% efficacy & possibly increasing over time

Press release for interim efficacy results from the US trial for 32,449 people, randomized 2:1 to placebo (140 events - symptomatic Covid-19)... 1/n

astrazeneca.com/content/astraz…

... Typo in previous tweet: 141 events. (No confidence intervals provided.)

....2/n

...Vaccine efficacy was consistent across ethnicity & age, include older. It was 80% for people aged 65 & older.

No breakdown of events by vaccine & placebo...3/n

...No one had CVST in this trial (although with only 30,000, you wouldn't expect any either, based on the European experience)...4/n

...This is still a younger group than the mRNA trials - 20% are 65 & over. It's going to very interesting to see the eventual breakdown of solicited adverse events for younger & older when we get final results...5/n

...Ah...doesn't seem they have an indication from this trial on whether it could increase over time, so my first tweet was over-optimistic there. Doesn't matter: 79% is high efficacy. Just shows how important having a good big trial is, doesn't it? ...6/n

... I don't know if we'll ever know, but as I tweeted, been wondering if there'd be an impact from not having placebo control. Going to be an interesting question for the future

https://twitter.com/hildabast/status/1357972379658461184

TY, FDA &co for insisting on this trial!

Ending where I started: 🥳 7/7

PS: I've been alerted by @BertrandBio (TY!) that I may be wrong on comparability of age groups with the mRNA vaccines, so please ignore that part of a tweet above. (Still interested in breakdown of adverse events by age, though.)