Thread by @Bob_Wachter

1/ Covid (@UCSF) Chronicles, Day 331

Today, UCSF Medicine Grand Rounds. I'll start w/ quick update on local scene & then review the terrific presentation on vaccines and masks by @monicagandhi9. The entire 75 minute conference is here – worth watching:

2/ While I’ll cover Monica’s presentation in this thread, there's more. At 39:30 Marguerita Lightfoot, chief of Division of Prevention Sciences, discussed vaccine hesitancy in communities of color. At 52:00, Robert Rodriguez, @UCSF Prof. of Emergency Medicine, & @DrEricGoosby…

3/ …@UCSF Professor of Medicine & former UN Special Envoy on TB, discussed their experience on President Biden’s Covid-19 Advisory Board. Just as @Atul_Gawande told me @inthebubblepod
tinyurl.com/13honosl, Rob & Eric were impressed by the Biden team,….

4/ … and immensely frustrated by the fact that they got zero support from anyone in the prior administration. (In a normal world, outgoing agencies prepare big briefing books with current status, data, etc. With Trump transition: nada.) Interesting discussion, worth watching.

5/ Before I do Grand Rounds, quick recap of the #'s – all going in right direction. @UCSFHospitals, 45 Covid pts, 10 on vents. Slow improvement continues (Fig). More impressive: test positivity rate is down to 2.2% overall – 7.1% in pts w/ symptoms (was 21% one month ago) and…

6/ …1.3% in asymptomatic patients (was ~4% one month ago) (Fig). As always, this is my poor man’s way of guessing the odds that a person near me in a SF store has asymptomatic Covid. So even if 5% of Covid in NorCal is the UK (or a similarly more infectious CA) variant,…

7/ …, a person is still vastly less likely to be infected now than in January due to the lower prevalence. This is a key principle: risk of an encounter is the product of the physics of the encounter (distance, masking, contagiousness of the virus) AND the probability that the…

8/ …nearby person/people are carrying SARS-CoV-2. So fall in cases/test positivity rates are critical & make things far safer now than last month, notwithstanding the growing prevalence of more infectious variants. But can’t let guard down since prevalence of variants going up.

9/ In SF: falling cases, hospitalizations, & test positivity consistent w/ @UCSF. 143 cases/d, down 2/3rds in past mth (Fig L). Test pos 2.9%. Hospitalizations 135, down 50% from peak (Fig R). All good, & strong evidence that more infectious variants aren’t a major factor… yet.

10/ Won’t go through all the other #s but they're consistent w/ drops in SF. Map (@axios & @COVID19Tracking) shows improvements in every state – combo of end of holidays, changes in behavior, & immunity (mostly natural, tho vaccination will begin to play a bigger role over time).

11/ Speaking of vaccination, here are highlights of @MonicaGandhi9's talk (6:10-39:30 in Grand Rds). On this useful slide, Monica summarizes trial results for 6 major vaccines. Key: efficacy against mild disease varies, but all are >95% protective against hospitalization.

12/ Starting @ 14:55, Monica reviews in detail results of Pfizer, Moderna, and J&J trials. Slide shows efficacy results from J&J, which should be a slam dunk for EUA approval after FDA advisory cmte meets on Feb 26. Approval will add big new supply, & far easier option for many.

13/ (At 52:30, Rob Rodriguez discusses work he and his group are doing to vaccinate people in ERs – particularly marginally housed and others who don’t have a PCP and can’t make it to a pharmacy or hospital. How much easier that would be if patients only needed a single shot!)

14/ Monica's been quite public about her belief that – while we can’t say for sure how MUCH vaccination lowers viral carriage/transmission – we CAN be confident that it does lower it somewhat. Her 4 lines of evidence are on this slide, and are pretty convincing, at least to me.

15/ Want real world evidence that vaccination works? Here’s data from Israel, which made deal w/ Pfizer that allowed country to vaccinate way faster than anyone else in world (Israel: 68 doses/100 people; US 15/100). Curve shows vaccine’s major impact on cases, hospitalization.

16/ How worried to be about variants & vaccine-resistance? A little, but, per Monica, not too much. On L, quote from @UCSF virologist Warner Greene on fact that J&J appears to prevent severe disease, even w/ So. African variant. On R, summary of why she’s not terribly concerned.

17/ Monica (& others) feel messaging re: vaccines has been too negative, including “you can’t change your behavior after vaccination.” Here’s her summary, including a rec that it’s ok for 2 vaccinated people to mingle without restrictions. While CDC hasn’t endorsed that yet,…

18/ … new rec that quarantine isn’t needed if vaccinated person is exposed seems like a prelude to a rec that vaccinated folks can mingle freely. I’m still a bit cautious about this (I still maintain a little distance) but suspect that this rec is coming. tinyurl.com/3t8ostfe

19/ Finally, CDC endorsed advice that Monica & aerosol expert @linseymarr helped craft tinyurl.com/g8o6w5zy: benefits of double masking to increase protection. Key is both better filtration with 2 masks & fewer gaps. Particularly w/ variants growing, this seems sensible.

20/ After the talk (at 35:00), we did lightning round of hot vaccine topics. A) Pregnancy & vaccines: “mRNA vaccines are very safe... no biological reason to think they wouldn’t be.” B) Duration of immunity after vaccination: some indication that combo of B & T cell response…

21/ …may last for many years (maybe 10 or more), though might shorten with variants; C) What kind of mask does she wear?: “I like cloth with an insert”; D) Might we be able to get away with single dose of mRNA vaccine after past infection? Very enthusiastic; once peer reviewed…

22/ … paper is out, it may be ready for prime time.; E) Delayed 2nd doses: “I liked your idea from the beginning, and I like it today, because of the Israel data” (as well as UK data). “I really applaud getting the population immunized more quickly.” tinyurl.com/4gw77p08

23/ Finally, F) "If you could get J&J today or wait a month for Pfizer or Moderna to be available, what would you do?" Answer: “I would get the J&J – I’m so excited about the reduction of severe disease and the single dose.”

24/ Kudo’s to Monica; her talk is a superb deep dive in to the current & future state of vaccination and new recommendations on masking. Other talks were great too. Again, Grand Rounds is here (75 minutes):

25/ I also hope you’ll listen @inthebubblepod, incl. inspiring show yesterday w/ @Captsully Sully Sullenberger. Coming next Monday, I talk to @ProfEmilyOster on Covid & the schools. And next Thursday @UCSF grand rounds: more w/ @atul_gawande. Stay safe.
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