Which arm will you get your next COVID booster in?

Well, here's something I never thought about. Turns out, there may be a bigger immune response if you get your next COVID booster shot in the same arm as the last one.

lt sounds improbable, but apparently there is science behind the idea. A (reasonably small) study done at Saarland University Hospital in Germany suggests that T-cell immunity is significantly better (67%) in those who used the same arm than in those who changed arms (43%). This may be because the lymph nodes where the immune response is found are re-stimulated, causing a greater immunological response.

Also, it did not actually find a significantly larger number of antibodies, but those antibodies that were present were better at binding to the viral spike proteins, which are responsible for the coronavirus entering the host's cells.

Now, all of this may or may not lead to an improved immune response in practice. But hey, it's worth a try, right?