I don’t know the answer, I don’t think anyone knows yet. Some more questions to add: are they suggesting a booster because they are considering actually changing the target of the vaccine because of new strains? Or, just to boost antibodies using the exact same vaccine? I have tried to find information on whether the flu vaccine actually loses efficacy in such a short time (under a year) or if the yearly vaccine is purely suggested because of new strains that it targets. Is the flu vaccine efficacy based on the nature of the vaccine and that it is a guess regarding what strains will be moving the population, and it is an imperfect guess, or that the vaccine even when perfectly guessing which flus will be here sill has such low efficacy? I know we have gone back and forth before about how efficacy is figured for the covid vaccine, I still question how the numbers are derived and if they are derived the same way for each type of vaccine. I really think we need nitty gritty science knowledge and no double talk to find out the answer. Have scientists ever bothered to test how long antibodies last for a flu vaccine? Or, they don’t care, because most years there is at least one new strain in the vaccine. Back to covid, if we come up with good treatments we can expose vaccinated people to the virus. I think you mentioned a while back they were doing that type of study in some country.