yes on average flu vaccine protect about 50 percent of the time but when they reach 75% they are quite good and can stop the spread. the classic vaccine made from inactivated strain are called sterilizing vaccines, they kill the virus, however the new method, using mRNA are not sterilizing at all, they work very differently and are far less effective but are easy to mass produce.
in my rush i misinterpreted some data, it was present in many countries simultaneously in the past also , sorry about that but now since nov 2023 it has an abnormally increased rate of mutations, now this if troublesome it could indicate it is a lab made, genetically modified strain but nothing conclusive yet. but i will watch closely. If only I still had access to by lab.. ( I am now retired) LOL.
cheers