From your linked study:oh ffs.... do you even read what's posted in THIS thread?
You need to read the content at this link slowly and THEN take up any arguments you have with the UK.
btw... I'm STILL waiting for YOUR source
The previous finding of reduced overall risk of hospitalisation for Omicron compared to Delta is confirmed by the updated Study 1. In addition, both studies find a substantial reduction in risk of hospitalisation for Omicron cases after 3 doses of vaccine compared to those who are unvaccinated, with overlapping estimate.....
And.....After 3 doses of vaccine, the risk of hospitalisation for a symptomatic case identified with Omicron through community testing was estimated to be reduced by 68% (42 to 82%) when compared to similar individuals with Omicron who were not vaccinated (after adjusting for age, gender, previous positive test, region, ethnicity, clinically extremely vulnerable status, risk group status and period).
So they are comparing unvaccinated vs three shots. Later on there is a shot showing a breakdown on 0, 1, 2, or 3 shots and comparing hospitalization and death rates which shows some effectiveness of a third booster. But there are several issues with the study. One it is a small group of patients so a change in a dozen cases has large impact on data. Second, the cutoff date of study was Dec 29th which was five weeks after the announcement of Omicron in SAfrica. Hardly time for the infections to run their course.
So the booster may have some benefits. But it appears that it is far less effective against Omicron.