Did I ruin my vaccination? Quercetin and antibody response
March 28, 2021 5:33 PM   Subscribe

I came across this abstract, which suggests that quercetin supplements reduce antibody response in...a non-coronavirus. But I have been taking quercetin.

The conclusion of the abstract says:

Compared to placebo, Q‐1000 attenuated post‐vaccination increases in IgG for H1N1 and B (but not H3N2) and significantly reduced post‐vaccination IgG to all viruses combined by 83% (P=0.025). In conclusion, Q supplementation does not improve the AB response to influenza vaccination.

Does this literally mean you have 83% less protection from a virus?

I have been taking 500g quercetin every other day. This is a lot less than the study, and the study isn't about coronaviruses and the vaccine is an inactivated virus one, but could the mechanism be the same? "Does quercetin ruin vaccines" is not really a burning research question and I couldn't find anything else.

I had my first Pfizer shot almost two weeks ago, have taken perhaps two quercetin capsules since (ran out).

I know a little science is a dangerous thing but I'd really appreciate some thoughts from people with more expertise.
posted by Frowner to Health & Fitness (4 answers total)
IAAD but not your doctor, nor am I a vaccine expert or infectious disease specialist, this is not medical advice, etc etc.

This appears to be an abstract only, no actual paper. Abstracts are generally not peer-reviewed; they are conference presentations, and some conferences will accept ANYTHING. I searched for but could not find the accompanying paper in PubMed/Medline. The linked DOI (which is supposed to be a permanent identifier) does not exist. So right off the bat, I'm sketched out.

Also notably, the study apparently did test 500 mg pills but doesn't clearly state what happened to that group. Maybe that's because of word limits on abstracts, but otherwise it's a sign of bad science when you ignore 39% of your data. Speaking of which, the groups are numerically uneven, also a sign of bad science/bad randomization unless there is something else (e.g. unbalanced drop-out) that isn't being stated in the abstract.

That's not even touching the differences between flu/covid and vaccine delivery methods and the minimal exposure you had to quercetin post-vaccine (2 days vs 4 weeks of supplementation). Just from a pure science perspective, I see a lot of red flags, which maybe explains why this study never got published. To me, it's worth about as much as the pixels it's printed with.
posted by basalganglia at 6:50 PM on March 28, 2021 [5 favorites]

If I'm interpreting this right, that study was asking "does quercetin boost immune response after vaccination?" and they basically came to the conclusion that it didn't really do much. If there was a valid takeaway (and basalganglia addresses the validity questions well above) then it seems the conclusion is "meh, doesn't do much" and not that quercetin made the immune response any worse.
posted by augustimagination at 7:41 PM on March 28, 2021 [1 favorite]

Ok, because I empathize with spiraling medical anxiety I just read this whole dang pig study, which has vaccinated pigs, vaccinated/quercetin supplemented pigs, and untreated pigs with a challenge study where all three groups were then exposed to the same pig respiratory virus at day 28. The difference in antibody titers between the vaccinated and vaccinated + supplemented pigs are nonsignificant. The differences between both of those vs the unvaccinated pigs are huge. I think you're fine. It does seem like quercetin boosts the innate immune response a bit while dampening inflammatory responses, so I might avoid it for round two, but mostly just to make yourself feel better (like my choice to not take NSAIDS despite being feverish and feeling like absolute crap for a day after shot 2). Please go easy on yourself!
posted by deludingmyself at 9:05 PM on March 28, 2021

Two things I notice reading that abstract:
1. It is funded by the maker of quercetin supplements (and coca-cola). This doesn't mean it's definitely bad science or anything but...take it all with a grain of salt.
2. Study participants took daily quercetin for 4 weeks after vaccination, compared to your couple pills. Your dose post-vaccination is dramatically lower than theirs.
posted by lulu68 at 12:37 AM on March 29, 2021 [1 favorite]

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