For the flu, absolutely. It mutates rapidly and one can get the virus, mount an effective defense, and then the virus mutates and escapes the immune defense. T

For the flu, absolutely. It mutates rapidly and one can get the virus, mount an effective defense, and then the virus mutates and escapes the immune defense. This happens. It is known that coronaviruses mutate much more slowly than influenza for fundamental reasons. It is highly probably but not proven that this much slower rate is sufficient to preclude the "waves" you refer to.