[mrguyorama]

When I got my first shot, I was interested in the half life of the mRNA, because I understand how mRNA works and the concept of "how long is the spike protein being made vs how long I feel adverse effects from the shot" amused me.

I got my first shot in April 2021. What I found at the time was that manufacturers mostly did not provide that info, or when they did, it was vaguely given (usually described as "a couple weeks"). There are a multitude of potential reasons: They didn't know (unlikely), the PR people asked didn't know, it was different for different shot brands, it is probably variable person to person, and the most important one in my opinion, they were aware that it was a stupidly politicized issue and didn't feel that the specific info of "how long" would be useful to the community and un-useful to the vaccine skeptic community, and were very confident that an mRNA based solution would be 100% degraded "eventually" just because of how cells work.