Covid Bivalent boosters

Should have made a bivalent booster targeting BA.2 and BA.4-5. The original version of the virus is pretty much out of circulation, so that half of the booster seems pointless. I’d not be surprised to see BA.2.75 drive the next wave of infections outside of India.

The inclusion of the original viral sequence is to boost a recall response. This is a memory response which differs from a naive response to a different sequence. There is also some evidence that signaling both the old and new sequences simultaneously could lead to a more efficient BA.4-5 response through somatic hypermutation as the immune system sees two similar antigens indicating a mutation has occurred.


Good info, thanks for the explanation. Still wish there were a version w/o the original wuhan strain for those of us with likely viral persistence from previous bouts with covid.

Edit - I am referring to the WSJ article posted in the comment I am replying to.

Adding to the other comments, this is a discussion of whether the bivalent booster is better and if so how much than a booster with just the original ancestral strain. There is some genuine, good faith disagreement as to the quality of the evidence that the bivalent is better, and this is what is being talked about in this opinion piece. My take is that the evidence is not that strong, however there is also not evidence that it is less effective, along with good reason to believe that it is likely to be more effective.
If you ignore clear anti-vaxers (and you should), there is little disagreement that that boosters are valuable for preventing severe disease and death.

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In my opinion, that’s not what this conversation is about. The OP asked about experience with side effects from the bivalent booster … and one may presume that the question was in relation to training impact from the shot.

I don’t work for TR, nor am I an ambassador nor in any way affiliated with them directly or indirectly other than the fee I pay for their software. With that said, I think we should limit this conversation to experience with the bivalent booster vis a vis “getting faster” and leave opinions on its efficacy, necessity, availability and/or epidemiological value to other message boards and discussions … otherwise this discussion will be (rightly) shut down.

As noted earlier in this thread, I got my bivalent to booster a little over a week ago and had no side effects which impacted my training, or ability to train, at all.

Good luck to you all.

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Just to clarify, my “this is a discussion” is referring to the Wall Street Journal opinion piece that was in the comment that I was directly replying to.
You are correct in regard to what this thread is discussing.

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The way pharma companies were talking at the beginning you’d think all the anti-vaxers would be dead by now. :rofl:


I mean, the data at this point is fairly clear, the large majority of people still dying from covid did not get vaccinated.


This is a weird opinion piece, Pfizer did a phase 2/3 clinical trial on their bivalent(and omicron specific monovalent) booster that was completed before EUA,

This was completed back in June

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Pfizer bivalent booster yesterday midday with 30 minute TR sweet spot session following.

Overnight had some chills / fever, Garmin measured high stress levels, poor sleep and almost no body battery recharge - interesting.

By midday today, however, feeling fairly normal and aim to get a mid-long run tomorrow morning.

All of that being said, I had mild symptoms for about 3 days (cold-like) about 2 months ago with Covid. Even though my symptoms faded fairly quickly my run and cycle training took a hit for about 2 weeks. For this reason I got the booster and hope of I catch it again my downtime will be lessened.

On side effects and effect on training: got my bivalent booster on Wed. Today is Sat. Zero side effects, not even “the arm”. Had not any side effects with my three previous jabs either.

Did a 70min easy spin right after the jab. A threshold session on the MTB on the day after and a 2.5h mountain trail run yesterday. Zero negative impact. Heart rate was as expected.

Took my 77year old mom with me to the vax center. She got her 5th. Zero side effects with any of them. Went for a long walk on Wed after the jab. Does all her shopping and grandchildren school pick-up duties by bike. No impact noticed. It’s quite hilly here and she does not have an E-Bike.

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There’s also genuine disagreement regarding the recommendation of timing after infection for boosters.