We found that 7-13 days after the booster shot there is a 48-68% 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%.
But this is a few months ago, not Omicron. I can’t find any detailed analysis of Omicron data along these lines, probably it doesn’t exist yet, sample sizes may not be large enough to know much more than the fact that it’s effective.
If it were me - would I spend a few hours trying to find an earlier appointment? Yes. Would I cancel important social events - assuming they are with sensible people who are at least fully immunized with 2 shots - probably not.
I had minimal side effects from my booster, but I also had about half the side effect from the second dose as the first dose - first dose had me in bed pretty much incapacitated for 24 hours.
Riffing off of Riemann’s suggestion to try to get your booster earlier than you’ve currently got it scheduled:
I don’t know if this is available where you live, but around here (New Orleans metro area) many independent non-chain pharmacies and clinics are giving walk-in COVID boosters. No appointment necessary. It’s worth asking around or looking on your state’s Health Department website to see what kinds of places besides the big chains are giving boosters in your area.
My understanding (from another poster here) is that full protection from a booster shot is also two weeks, because that is the amount of time it takes the body to physically get the appropriate cells online.
The adaptive response to primary infection takes 1-2 weeks. But the response of memory cells to secondary infection is much quicker. That’s the basis of vaccination - the vaccination simulates the primary infection and establishes immunological memory for the antigen, so if the real thing shows up it will be neutralized quickly. A booster shot looks like a repeat infection, so it will stimulate rapid production of a lot of antibodies. If you were exposed to the virus a couple of days after your booster shot, you’d almost certainly be much better off, because there would not even be the that short delay - you’d already have a lot more antibodies circulating.
On the other hand, repeat exposure to the same antigen stimulates affinity maturation, the selection of clones with greater specificity for the antigen. That process takes longer, and that may be the basis for the enhanced protection from the booster in the longer term. So you may not get better antibodies until a couple of weeks have passed.
So I don’t think you can really predict from basic principles exactly what degree of protection you’re likely to have at various times after the booster - but it’s extremely unlikely that you get no benefit until 2 weeks have passed.
I get regular texts from the state of NJ that certain public schools in my area have walk-in availability. Since this week was invariably going to be a busy week at work, and Thanksgiving was a couple weeks ago etc., I didn’t want to deal with the side effects, which hit me hard after #2, during these periods. I’m scheduled for Monday at my local CVS, so I’ll stick with that one. That is now 5 days away, so hopefully reduces the chance of illness even if I am exposed in the next few days.
I agree with what @Riemann is saying. Maximum protection with even better antibodies may take a few weeks, but a booster should start giving you more antibodies within days. I don’t see any papers reporting this but I do remember the papers showing that antibody levels started increasing faster after the second shot than after the first shot.
I got my second shingles shot today and listened to hear if anyone was asking for COVID. The person in front of me wanted a flu shot and the person behind me wanted a shingles shot. I asked my shot giver about boosters and she said they were now appointment only because they were wasting so much of the vaccination to spoilage.
Just got my Moderna #3. This time I did the counter-intuitive and got the jab in the right arm, under the hypothesis that the more active arm will stay looser, move more, thereby reducing the pain. Let’s see.
ETA: I should point out that my arm pain was very minor both times, but still annoying.
I also got my third shot a last week (technically 1 day early). I went with my right arm simply because it was the one closest to the nurse, and she asked if it was okay. I did not feel it hampered movement. It just hurt to lay on. Though I do suspect that where they inject plays a part.
My dad got his shot at Walmart, as the hospital’s clinic was closed for Thanksgiving weekend. They gave him the shot lower down on his arm, and he says it hurt even at the time of the shot. When he got the shot nearer to his shoulder, it didn’t hurt at all, suggesting you don’t feel as much pain up thee. And the primary site of the arm pain I’ve experienced is around the injection site.
When I joined the Air Force everyone got all of their childhood vaccinations as well as a few other things at once. The DI’s told everyone that after we got shot we should do push-ups to get the vaccines moving around which would reduce the pain. I did push-ups after the first round of shots, I didn’t do them after the second round and didn’t notice any difference in pain or side effects but I’m a weenie. Let me know if it worked for you, OK?