I've posted about this before, but I think it's worth repeating.
It looks like the vaccine has essentially hit a wall regarding its usefulness in preventing disease.
After 5 months, the Pfizer booster (third shot) falls to 31% effectiveness against Omicron. I am almost at that 5-month mark.
The fourth dose, while giving a small benefit, is not a significant boost to protection like the third dose was:
https://www.nature.com/articles/d41586-022-00486-9
After four months, the Pfizer third dose also declined to just 78% efficacy in preventing hospitalization:
https://www.washingtonpost.com/healt...on-protection/
There isn't data (from what I can see) regarding the hospitalization efficacy after 5 months, but it could be considerably worse.
BOTTOM LINE:
Pretty soon everyone is going to be highly vulnerable to Omicron (or whatever variant follows), and it looks like another booster isn't the answer.
Omicron is rapidly declining in the US, so it's possible it will die out before it becomes too much of a problem. It's also 10x less severe than Delta. However, we might be getting to where it's going to be useless to attempt to prevent COVID transmission, similar to the way we treated the flu.