U.S. is now considering idea of a single vaccination shot, delaying shot #2 until months later. Last wk, I thought that was a bad idea – the trials that found 95% efficacy were 2 shots; why add extra complexity & a new curveball. But facts on the ground demand a rethink. (1/7)
The two main changes are the slower-than-expected vaccine rollout and the new variant virus being found in the U.S. Both demand that we turbocharge the process of getting a large chunk of the population at least partly protected. (2/7)
Here's my back-of-the-envelope math:
- Single shot seems to be about 80% protective after a month
- 2nd shot adds some efficacy (up to 95% protective), and maybe (tho not yet proven) some durability.
- New variant is here, and undoubtedly far more widespread than we know. (3/7)
- Variant is ~55% more infectious than old one. Even though it's not more deadly, this means that if we engage in same behaviors, many more will get Covid & thus far more will die. UK shows that once here, it spreads fast.
- We seem incapable of changing behavior very much. (4/7)
- As has been widely reported, the roll-out is going far slower than we hoped.
- According to most vaccine experts, delaying shot #2 by a few months is unlikely to materially diminish the ultimate effectiveness of two shots (critical point; we should be testing to be sure). (5/7)
Taken together, if we have vaccine doses to distribute in Jan-Apr, it seems increasingly evident that a strategy of getting as many people (particularly high-risk) their first shot ASAP will save far more lives than sticking with the two shot plan. (6/7)
Far better to have 100M people who are 80% protected than 50M people who are 95% protected, particularly as we are facing a foe that is getting smarter and nastier. Or at least it seems that way to me. You? (7/7)

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More from @Bob_Wachter

30 Dec 20
1/ Covid (@UCSF) Chronicles, Day 287

Today, a brief update on the local situation in SF & CA, and then a few reflections on a series of new failures in the U.S. that, sadly, make clear how difficult it is for our country to get execution right in the fight against Covid-19.
2/ First, a brief update on the local scene. Bottom line: not much change, which is either good or bad news, depending on how you feel about half-filled (or empty) glasses. Personally, I don’t feel great about it, since we’re just starting to see the impact of holiday mingling.
3/ TSA reported 1.3 million people screened at airports Sunday, a 60% decrease from last year but still an awful lot of travel for a country that should be staying home. After 10 months, the urge to be with friends & family is understandable, but the cost will be very high.
Read 25 tweets
25 Dec 20
1/ Covid (@UCSF) Chronicles, Day 282

Holiday greetings – hope you’re getting a little R&R. I’m on clinical svc @ucsfhospitals – welcome break from a Life of Zoom, leavened by a little Netflix. Today, update on Covid in SF/CA, & lessons from first 2 wks of vaccine distribution.
2/ @UCSFHospitals, 60 pts in hospital, 12 on vents (Fig on L). Curve shows we may have plateaued – at a pretty high # but one that isn’t overly stressing system. Our test positivity rates (Fig R) have inched down a bit in the past week. Maybe things are starting to turn around.
3/ SF cases up to 288/d (Fig L) – low when compared to many regions (incl. SoCal), but 10x SF's Oct cases. Test positivity still inching up, now 4.3%. 176 Covid pts in SF hospitals; perhaps hint of a plateau? (Fig R). Cumulative deaths=178, w/ only 12 in past 30d – amazingly low.
Read 25 tweets
19 Dec 20
1/ Covid (@UCSF) Chronicles, Day 276

Here’s my summary of yesterday’s fascinating grand rounds (sorry it's a day late), here: Far-ranging discussion re: the problems at the CDC, vaccine roll-out @ucsf, and the complex matter of immunity passports.
2/ Session began with a fireside chat w/ Julie Gerberding, a @UCSF adjunct faculty member who ran @CDCgov from 2002-2009, and led @Merck's vaccine development program afterwards. I asked Julie about how the CDC prepared for a pandemic during her tenure as director.
3/ “SARS was a wakeup call,” she said, particularly after post-9/11 anthrax attacks. “After that, we got very serious about influenza… it led to a major investment in pandemic preparedness,” including full scale table-top pandemic preparedness exercises with every state.
Read 25 tweets
15 Dec 20
1/ Covid (@UCSF) Chronicles, Day 272

The juxtaposition is jarring: the first U.S. vaccine recipient on the day we hit 300,000 deaths. So much tragedy amid the hopefulness. Today, after an update on SF, I’ll lay out some complex issues that will play out in the next few months.
2/ San Francisco is now seeing its first big surge, & everybody's asking when the city will turn things around. After having stomped on the curve in March & quickly turned back a surge in June, I thought – if anybody can control this surge – it would be SF. I may have been wrong.
3/ The curve of SF hospitalizations (Fig) shows no signs of plateau after 6 wks, despite stay-at-home orders (note that June surge had plateaued by 6 wks). The combo of pandemic fatigue, colder weather, and the holidays has given the virus the upper hand. We’re losing the battle.
Read 25 tweets
11 Dec 20
1/ Covid (@UCSF) Chronicles, Day 268

Today was Pfizer Vaccine Day @US_FDA, and the expert panel just recommended EUA approval tinyurl.com/y5u84jmx Next: FDA deliberates, but expect an EUA in next 1-2 days. As with All-Things-Covid, nothing is easy; now the hard part begins.
2/ Today: quick state of the pandemic, then potpourri of vaccine-related stuff.

SF still in our first true surge. @ucsfhospitals 39 Covid pts, 10 on vents (Fig). Test pos 11.9% in symptomatic pts, 1.6 in asymptomatics, both way up. In SF, cases now 181/d (vs ~30/d last mth)…
3/ …& 129 Covid pts in SF hospitals (vs ~25 last mth; Fig). Luckily, deaths have not yet ticked up: 165, still lowest rate in U.S. But with this many people in ICUs, more deaths can’t be far behind. SF test positivity rate is 3.4%, rising but still well below CA’s rate of 8.8%.
Read 25 tweets
5 Dec 20
1/ Covid (@UCSF) Chronicles, Day 263

Tonight a brief update on our local situation, as 5 Bay Area counties announce that the region will adopt CA’s stay-at-home orders, even before we hit the state’s 15% ICU capacity threshold. tinyurl.com/y3ou56qq It's a prudent move.
2/ Nobody wants to go backwards – we're all bummed out and exhausted. But in judging the decisions by the governor and our Bay Area leaders, I’m influenced by the words of former @HHSGov secretary @GovMikeLeavitt, below:
3/ The viral dynamics of Covid make it even harder to react in a timely way – we always have a tendency to act late as the hospitalizations we're seeing now reflect the behaviors and conditions of two weeks ago. It’s like looking at a star: what you see now happened a while ago.
Read 21 tweets

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