It’s not just them, vaccines aren’t always the same level of efficacy for everyone. Even normal healthy and vaccinated people can be susceptible without strong enough herd immunity.
And immunity can wane over time for some. I had to get the MMR series again when I started nursing school because I tested negative for rubella antibodies.
It’s not just them, vaccines aren’t always the same level of efficacy for everyone. Even normal healthy and vaccinated people can be susceptible without strong enough herd immunity.
And immunity can wane over time for some. I had to get the MMR series again when I started nursing school because I tested negative for rubella antibodies.