Covid-19 is unique and the 'flu' is not. Each time we get a flu shot it's for a different virus for the most part. As far as I know it's not an update or a reinforcing shot you get each year. But you could do a thorough investigation of the question for us?
Your rational approach is encouraging for this board!
You’re truly an ignoramus who just talks out his ass.
The other poster just said that experts are saying the COVID vaccine may need to be an annual vaccination, like the flu vaccine.