When do you get the boost from the Booster?

October 29, 2021 5:27 PM

Is there any lag time between the time one receives a Moderna booster shot and when it is considered as ‘active’? Elderly relative is scheduled for Moderna booster on the 11th and would like to go to dinner on Thanksgiving. Would they be considered as receiving all of any protection that a booster provides by then? We will also evaluate with more info on vax status of other guests once I get that too. Thanks.
posted by calgirl to Health & Fitness (6 answers total)

Yeah, two weeks is fine.
posted by kickingtheground at 5:52 PM on October 29, 2021

I actually Googled this today - Healthline quotes a study from Israel in this summary article that says 7-13 days after the mRNA booster (which include Pfizer and Moderna) and 14-20 for the "full" boost. Healthline is a health news aggregator and does reference outside sources, but it can be a bit clickbait-y and may not be doing actual independent reporting so I'd want some other sources too.

Meanwhile, a study from Israel concluded that a third booster shot of the mRNA vaccines appeared to significantly restore protective effects.

“We found that 7–13 days after the booster shot there is a 48–68 percent reduction in the odds of testing positive for SARS-CoV-2 infection, and that 14–20 days after the booster the marginal effectiveness increases to 70–84 percent,” the researchers from Maccabi Healthcare Services reported.

posted by rogerroger at 6:58 PM on October 29, 2021 [3 favorites]

Not scientific but: Two weeks is also the "rule of thumb" for how long it takes for a flu shot to take effect. I'm guessing this is more a function of the human immune system than of the particular vaccine in question.
posted by heatherlogan at 9:18 PM on October 29, 2021

7-13 days later reduction in TESTING positive, not catching the virus. Remember you've got a lag between catching it and testing it.

Either way two weeks is fine, but just wanted to point that little bit of semantics out.
posted by Lady Li at 11:38 PM on October 29, 2021

Also remember that they are still well-protected by the original two shots.
posted by Thorzdad at 6:37 AM on October 30, 2021 [1 favorite]

re: still well-protected by the original two shots.

A CDC chart in in a Business Insider Article (3rd from top) shows the recent risk of death for a fully vaxed 80+ to be just slightly less than an un-vaxed 50-64 yo.
posted by tinker at 8:59 AM on October 30, 2021