FDA Advisory Committee on Janssen Booster and Heterologous Dosing: Day 2

Dr. Arnold Monto, Acting Chair “Arnie” couldn’t get his camera to work right off the bat on this, Day Two of the FDA Advisory Committee meeting on COVID-19 vaccine boosters. The microphone mute virus was also an issue—again. One committee member had real problems with audio skipping, which the on-screen captioning could not fix. There were many on-screen notices of “indiscernible,” as well as comical errors, “public urine speakers.” That captioning reminded me of voice recognition software, which I tried to use when I dictated my clinical notes.

Early in the meeting, Arnie asked for a clarification of the voting question:

“10/15 Voting Question:

Question 1) Do available data support the safety and effectiveness of Janssen COVID-19 Vaccine for use under EUA as a booster dose in individuals 18 years and older at least 2 months after a single dose primary vaccination?

1a. If yes to # 1, do available data support that an interval of at least 6 months between a single primary dose and a booster dose may result in a more robust booster response?

2b. If no to # 1, do available data support the safety and effectiveness of Janssen COVID-19 Vaccine for use under EUA as a booster dose in individuals 18 years and older at least 6 months after a single dose primary vaccination?”

This led to what Sena and I thought was a hilarious “clarification” interaction between Arnie and Dr. Peter Marks. We couldn’t really follow it, mainly because we couldn’t stop laughing.  It reminded me of the “Who’s on First” routine by Abbott and Costello. However, Arnie said he understood it.

The Q&A session between the committee, the sponsor, and FDA seemed conflicted about the data on the efficacy of the Janssen vaccine. The FDA received a large amount of data from Janssen, but apparently got it too late to conduct its own analysis of it. There was the overall impression that the Janssen vaccine efficacy is lower than the mRNA vaccines. The participants on both the FDA and the sponsor side acknowledged that maybe part of the reason to hold today’s meeting was in view of the urgency to do something for those patients who got the Janssen vaccine. Most people acknowledged that the Janssen vaccine had good durability. Arnie kept the proceedings on a short leash as usual, and by the break for lunch at 11:25 AM CDT, it wasn’t very clear what the outlook was for the Janssen booster.

I’ll update after the break.

Several committee members advanced the idea that the Janssen vaccine is actually best considered a 2-dose vaccine rather than a 1 dose vaccine. They moved toward not calling the 2nd dose as a booster per se, and also seemed agreeable to simplifying the voting question above to only number 1, setting aside the a and b questions. Arnie called out “We need a simplification” and the group went along with it. Dr. Perlman suggested that it might be helpful to hear the presentation about heterologous boosting prior to addressing the voting question; however, Arnie and Dr. Marks thought heterologous boosting might be addressed as a separate EUA in the near future.

The committee voted only on the revised question:

Question 1) Do available data support the safety and effectiveness of Janssen COVID-19 Vaccine for use under EUA as a booster dose in individuals 18 years and older at least 2 months after a single dose primary vaccination?

The above was upvoted unanimously. The word “booster” might be changed to something like 2nd dose later.

After a 15-minute break, the heterologous (mix and match) vaccine boosting presentation will be given. I’ll update after that.

After the presentation on heterologous boosting, it seemed like mRNA boosting was stronger than Janssen boosting. A limitation was that this was an antibody data study only. The committee was impressed with the safety data. The discussion question to the committee was about what other studies they would want to see in order to evaluate an EUA to help guide decisions on, for example, how to boost the Janssen vaccine. Not all members thought an EUA was necessary for this issue. It sounded like some members wanted to see some flexibility in allowing for a fact sheet that would provide clear guidance on how to use heterologous boosting. In fact, some heterologous boosting is already happening out in the real world, which members acknowledged.

The meeting was adjourned at 2:30 PM CDT on the proverbial and a celebratory “You’re muted” reminder.

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