Some things to keep in mind when you see people dumping on "low efficacy" of "Chinese Covid vaccines", particularly based on that single medium-sized trial in Brazil of doses only 2 weeks apart...1/n

...There's the obvious ones: the results of this trial aren't the whole picture - not of the trials that are underway, nor of the way the vaccine is being used (doses more than 2 wks apart)...2/n

...The efficacy against fearsome outcomes was good in this trial - a vaccine that could prevent over 80% of the worst outcomes & reduce the severity in a major way is incredibly needed in a world bereft of enough options...3/n

...Critically, though, the outcome we care about are the effectiveness ones: & that's not just about what a vaccine can do, it's to do with acceptance, as well. The trade-off of lower efficacy is a very, very low rate of adverse events...4/n

...If the combination of traditional type of vaccine & very low adverse events could translate into high vaccine acceptance, then that could make an important difference. That's still an if, but it's one that matters...5/n

...We're seeing very high rates of people in many countries not wanting Covid vaccines because of, in large part, concerns about adverse events & what that means, which is very complex & personal...6/n https://twitter.com/hildabast/status/1381509731517263874

...Then consider Serrana in Brazil, where they reckoned about 30,000 were eligible to be vaxed & tried to get them all to sign up for Sinovac's CoronaVac: 28,000 did & over 27,000 accepted both doses... 7/n https://twitter.com/hildabast/status/1381509731517263874

...Others have yet to show that they can get that level of vax acceptance - what? over 90% of non-pregnant, vax-eligible adults? Let's wait & see how the group of trials of these vaxes stack up. But it will be effectiveness that matters in the end, not just potential efficacy. /8