Read the literature on why we have not had a successful corona vaccine ever in primates.
The dang things shift to fast and to much. Sort of like why we have a good measles vaccine but a mediocre flu shot.
Read the literature on why we have not had a successful corona vaccine ever in primates.
The dang things shift to fast and to much. Sort of like why we have a good measles vaccine but a mediocre flu shot.
The virus changes. More contagious variants becomes more common.
Vaccines make some variants less contagious. Variants that can evade vaccines are more contagious among the vaccinated. Variants that evade vaccines become more common.