degree of immunity from infection by the Omicron variant (tbd on the "BA.2" variant...not yet dominant in the U.S.)...also, the vaccines DO reduce the severity of the disease...see following link...
https://www.nih.gov/news-events/nih-research-matters/covid-19-vaccines-induce-immune-response-omicron
You, and others, can search my posts for "UCSF Grand Rounds" videos that show the data on Omicron and the vaccines...real numbers, if you'd like.
Link: https://news.harvard.edu/gazette/story/2022/01/no-omicron-immunity-without-booster-study-finds/