I am puzzled as to how long the booster is protective-- I don't want to get the 2nd booster before 6 months after the first booster. I just don't feel comfortable getting it sooner, but I wonder at what point does the 3rd shot wane to the point of not providing much protection. For me 6 months will be mid- May. I heard a physician speak on one of the cable channels this morning: she stated that they do not know how long immunity lasts with natural infection or with vaccines and she expressed concern about that.
I've read a lot of articles that talk about 4 months for first booster (3rd shot) of mRNA vaccines. I'm thinking of having the 2nd booster in early-to-mid May as cases start to rise in our region, and then, hopefully, when it is time for the flu shot in September, they will be offering a combo flu and covid shot, at least for seniors.