Thread by @Bob_Wachter

Covid (@UCSF) Chronicles, Day 237

Didn't plan to tweet today, but can’t resist a few quick takes on @pfizer vaccine news tinyurl.com/yygwoxwf

90% efficacy is far better than even most optimistic projections. An election analogy: these are CA results, rather than PA. (1/16)

The 90% is for preventing symptomatic disease (ie, fever, cough). But we don’t know yet how well this vaccine prevents severe symptoms that lead to hospitalizations, ICU admissions, & death. That’ll be key. It seems likely it will, but that still needs to be demonstrated. (2/16)

Now that the efficacy data are out, the next big question is safety. The need to wait two months to observe at least half the volunteers is the reason the vaccine won’t be ready to be considered by @US_FDA for an Emergency Use Authorization (EUA) until later this month. (3/16)

Three other vaccine trials (@JNJNews, @LillyPad & @AstraZeneca) were suspended at various times to analyze safety concerns tinyurl.com/y47toqjb @pfizer study was never suspended, making it unlikely that we’ll see high enough # of severe side effects to derail approval. (4/16)

Even if there's a rare side effect, 90% is so strong that overarching risk-benefit equation will still be positive for use in at-risk populations. But for people at relatively low risk (of catching Covid &, if they do, for bad outcome), we need to be sure it’s super safe. (5/16)

Pfizer has said that it can make 50 million doses available by year’s end, and 1.3 billion doses by the end of 2021. It’s a two-dose vaccine, so this means enough vaccine for 25 million people, who won’t all be in the U.S., available by January. (6/16)

And getting these doses packaged, frozen, shipped, tracked... is not a trivial undertaking. The Biden team will be brand new and this will be the 2021 Logistical Olympics. I'm far more hopeful about this than I would have been under Trump, but there are bound to be hiccups.(7/16)

Who will get the vaccine first (assuming it gets to the finish line)? Fig is from @theNAMedicine report on allocation tinyurl.com/y2qqq9cb Just Phase 1 (front-line responders, >65 in nursing homes, 2 or more chronic conditions) is 15% of population, or 50M people in U.S.(8/16)

This means that, under ideal circumstances, we won’t see a large chunk of population vaccinated till spring or summer (of course, other vaccines may work as well & shorten the timeline). This means that we still have an awful lot of Covid, and deaths, ahead of us. Be safe! (9/16)

Kudos to @pfizer for resisting the political pressure to rush this announcement tinyurl.com/y2crr86m. While some will undoubtedly claim that the timing was far from coincidental, it's not: November was when this analysis was supposed to come out. (10/16)

Kudos as well to Steve Hahn & the pros at the FDA. History will treat them kindly for having done the responsible thing, at least on vaccines. An early hydroxychloroquine-like approval would have shattered public trust, and trust is everything when it comes to vaccines. (11/16)

Speaking of which, I never bought the “50% of people won’t take a vaccine” mantra, despite the polls tinyurl.com/yye63dkf How can one answer that question thoughtfully without knowing data on vaccine efficacy & side effects, and without witnessing the approval process? (12/16)

If vaccine is truly 90% effective, is shown to have few side effects (& no dire late complications), & is approved via a credible process, I’d wager that the uptake will be more like 70-80%. This isn’t like childhood vaccines, given for diseases you’ve never seen before…(13/16)

…& you’ve never heard about anyone dying of. Measles & other childhood diseases don’t wreck your life, screw up your travel, make you lose your job or be unable to hug your grandkids. Of course, there’ll be anti-vaxxers, but they'll be a fringe, & marginalized, minority.(14/16)

Having Trump & team sidelined (though they’ll have their social media megaphone) will be helpful. And watching how the media handled the Hunter Biden silliness (& is handling election results) gives one hope that their approach to baseless conspiracy theories has matured. (15/16)

Speaking of Trump, one can only imagine how he feels today – this was the “October surprise” he was hoping for. The ultimate irony is that vaccines are the one part of the Covid response that he got right, and their payoff will be seen in the first days of Biden's term.(16/16)