Thread by @HelenBranswell

1. #ACIP meets today. I'll be tweeting on the meeting in this thread.
When it was first announced, this was going to be a 2-day meeting; now only 1.
If you want to listen to the meeting, you can do so from here: video.ibm.com/channel/VWBXKB…

2. Contrary to popular opinion, this #ACIP meeting isn't primarily about whether Americans who got mRNA vaccines need a 3rd dose starting in Sept., as per the policy announced by the Biden administration. Only 45 minutes of the 6.5 hour meeting has been set aside for boosters.

3. Why so little discussion about boosters? Not a lot of data at this point.
Pfizer only recently applied to @US_FDA for a 3rd shot; Moderna hasn't yet applied. #ACIP will review the data Pfizer submitted to FDA when it becomes available to ACIP, chair Grace Lee told me.

4. So what's today's #ACIP meeting about? Mostly about re-reviewing the Pfizer vaccine, now that it has transitioned from use under an EUA to a BLA (translation: from emergency use to full license).
ACIP has go back over the data for the vaccine & recommend its use to @CDCgov.

5. The #ACIP meeting agenda is here. Starting momentarily. cdc.gov/vaccines/acip/…

6. #ACIP chair Grace Lee says that the committee will follow its normal processes when it looks at the issue of whether to recommend mRNA boosters.
She also says another ACIP special meeting will take place soon.

7. #ACIP Covid vaccine work group lead Matt Daley notes never before has a vaccine been considered for a recommendation based on such a big data package. In addition to the +40,000 people in Pfizer-BioNTech's P3 trial, there are observation data studies including 680K subjects.

8. #ACIP asked Pfizer when data will be available from its ongoing trial looking at efficacy of an additional booster shot.
Company tells ACIP it should have some data by late Sept, early Oct.
The Biden administration has said boosters will start to be administered Sept. 20. 🤔

9. How do @US_FDA & #ACIP/@CDCgov approve a Pfizer booster shot without data showing it improves the vaccine's efficacy?
How did the Sept. 20 date get chosen?

10. In the public comment period, vaccine eminence grise Stanley Plotkin argues a 3rd dose of the mRNA vaccines shouldn't be called a booster, it should always have been part of the original vaccine series. Inactivated vaxes benefit from a dose given 4-6 months after first doses.

11. @CDCgov's John Su is telling #ACIP about adverse events following receipt of Pfizer vaccine. Here's a slide updating on reported cases of myocarditis & periocarditis in people under 30.

12. @CDCgov's Su tells #ACIP that 77% of people who developed myo- or periocarditis after getting the Pfizer vaccine recovered by the time of report or follow up.
Su suggests there aren't clear data on whether there are differences of incidences based on race or ethnicity.

13. A further update on adverse events after mRNA vaccines suggests that the rate of anaphylaxis after receipt of vaccine has settled in to a rate of about 5 cases per million doses given. Early in the vaccine rollout it seems like the rate was about double that. #ACIP

14. #ACIP member Sarah Long notes that the vast majority (80%) of myo-periocarditis cases seen following receipt of the mRNA vaccines are not typical myo- or periocarditis cases. They are milder & resolve sooner.

15. @CDCgov vaccine expert Hannah Rosenblum is presenting an analysis of the risks & benefits of use of the Pfizer #Covid vaccine.
Rosenblum says there have been no reported deaths among people who developed myo- or periocardititis after receiving the vaccine.

16. Rosenblum showed 2 interesting slides just now. For every 1M doses of the Pfizer-BioNTech used, benefits of infections averted (blue bars) clearly outweigh the risks of adverse events (red bars). #ACIP

17. Rosenblum also showed how the benefits of cases averted stack up against the risk of adverse events if the Pfizer vaccine is less efficacious now than it was in the clinical trials — as studies from Israel & elsewhere are suggesting.
Benefits still outweigh risks. #ACIP

18. The current surge of #Covid cases in the US is really straining hospital ICU capacity, #ACIP was told, with 23 states reporting over 80% of ICU capacity is taken up with Covid patients. This strain poses a danger to all people who need significant hospital care.

19. Vote on whether to recommend the Pfizer vaccine about to happen at #ACIP. There will be no surprises.
Use of the vaccine in children 12-15 yo will continue to occur under an EUA, should this pass. (It will pass.)

20. #ACIP votes 14 - 0 to recommend use of the Pfizer #Covid19 vaccine.
For those wondering, ACIP is currently down 1 member. Normal roster is 15 members.

21. #ACIP chair Grace Lee reminds the public that the license for the Pfizer-BioNTech vaccine includes its use by pregnant women, who are as a group are undervaccinated against Covid.

22. #ACIP is now going to have a brief session on Covid booster shots, which the administration has already said will be used in the US starting Sept. 20.
There will not be a vote on this today.

23. @CDCgov's Sara Oliver is making the presentation on boosters. She notes that just because there may be a 3rd shot in the primary Pfizer regimen does not mean annual boosters will be needed.

24. @CDCgov's Oliver noted #ACIP's Covid vaccine work group believes the top priority for a booster dose policy needs to be aimed at preventing severe disease in high risk people. Preventing mild disease may not be possible.

25. @CDCgov's Oliver said the Covid vaccine work group is also considering global implications of the US booster policy. Big pockets of unvaxxed people around the globe raise the risk of new variants; 3rd doses in the US are doses that cannot be used elsewhere.

26. @CDCgov's Oliver shows a schematic that illustrates how the rollout of a 3rd dose program in the US might be staged. #ACIP

27. A @CDCgov staffer whose name I did not catch is now warning vaccine providers not to give the Pfizer vaccine off label (ie in children under 12, giving additional doses to people who aren't currently eligible). #ACIP

28. The @CDCgov person who warned vaccine providers not to use the Pfizer vaccine off label cautioned that they might not have liability protection & the people vaccinated might not be eligible for compensation if they wanted to make a claim for vaccine-related injury. #ACIP

29. We're hearing a little shade from #ACIP member Beth Bell in the discussion on whether boosters are needed: "Process really does matter."
Getting more people to get vaccinated has to be a higher priority, Bell says.
(Dunno how a vote on boosters would go if held today.)

30. #ACIP Keipp Talbot also raising concerns about policy on boosters being set from the White House before @US_FDA / ACIP/ @CDCgov evaluate the data on the need for / benefits of adding a 3rd dose to the Pfizer vaccine regimen.

31. Circling back to tweets #27 & #28 in this series: The @CDCgov staffer who spoke warned that off-label use of the Pfizer (or any) Covid vaccine said people who give or get additional unauthorized doses may not be covered by the PREP Act, which provides liability coverage.

32. Phyllis Arthur from BIO (liaison to #ACIP) pleads for clarity on whether the US is talking about a 3rd dose vs a booster dose. Her point is really well taken but Pfizer itself applied to @US_FDA for a booster, not a 3rd dose in the primary series.

33. Someone kindly (I mean this) pointed out I misspelled pericarditis earlier in this thread.
Apologies.
Said it before, have to say it again: Everybody needs an editor — especially me.

34. @DocJeffD says we need to reset our expectations for Covid vaccines.
I think someone wrote about that recently.... statnews.com/2021/08/25/cov…

35. #ACIP adjourns.
Executive secretary Amanda Cohn tells members to be on the lookout for additional special meetings to discuss data on 3rd doses or boosters.

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