Every over heard a conversation between a Doc and a Vet? The Doc says ‘I wish Humans needed a annual injection like dogs, because I get to see them once a year for a check up and can head off any health problems’. The Vet replies ‘Yes I have no problem with my Patients, they turn up 12 months to the precise hour. However I do not earn as much as you, because my patients never get any serious illness’.
Therefore once a year can keep you healthy for life.
Best of Luck

If you are a female of college age once a year is more than enough. Your tests and results can be ordered and interpreted by a qualified NP without difficulty. Everybody gets a little short of breath after 4 flights.