Considering the transmissibility and ability to partially escape the immune system with the new variant that's not a good metric at all. However, those who are boosted have a reduction in risk of infection (depends on vaccine) of 70-88%, which ain't shabby. Prevention of severe disease, hospitalization, and death are even better. Yes, yes, I know this version is "milder", but that does not mean what most seem to think it means. I saw an article today explain that (regarding severe disease/hospitalization) 10% of 3,000 is still less than 3% of 12,000 - in other words the transmissibility and added new infections are likely to cause more illness, death, and disruption of the health system than anything before it.