[danhor]

Biontech (and probably all other vaccine manufacturers) are working on it and expect to have it available in march: https://investors.biontech.de/news-releases/news-release-det...

The omicron surge is happening now so health authorities are looking at solutions and a third shot worked great, so a fourth one is an obvious (short term) solution. Unfortunately it doesn't seem to work.

[usrusr]

But the fourth dose did work, just not significantly better than the third. So for people who might have had their third too long in the past to still be confident about their imminent encounter with omicron, it is exactly the obvious short term solution you describe.