> The question is why COVID vaccine is so harsh, and why is it different than a typical flu vaccine?
I had a pretty bad day after the second dose of Moderna - high fever, etc. Symptoms mostly dissipated after 24 hours of the shot.
I have my suspicions about why the COVID vaccines have tended to have more severe reactivity as compared to the flu vaccine - they were designed to trigger a very strong immune response & subsequent antibody titer, probably a lot more than might be required for protection in hindsight. The current crop of emergency use authorized vaccines have virtually 100% protection against severe COVID - which is great. My guess is that halving the antibody titer would have yielded something like 95% protection, and probably given you less reactivity as well. The manufacturers have erred on the side of caution, probably rightly so. By comparison the flu shot for last year's flu season had an effectiveness in the range of 50%. Of course, the thing that dings flu shot effectiveness is variant strains, while all the current COVID vaccines were designed from the original Wuhan strain (?), and likely have varying effectiveness against variant strains.
I had a pretty bad day after the second dose of Moderna - high fever, etc. Symptoms mostly dissipated after 24 hours of the shot.
I have my suspicions about why the COVID vaccines have tended to have more severe reactivity as compared to the flu vaccine - they were designed to trigger a very strong immune response & subsequent antibody titer, probably a lot more than might be required for protection in hindsight. The current crop of emergency use authorized vaccines have virtually 100% protection against severe COVID - which is great. My guess is that halving the antibody titer would have yielded something like 95% protection, and probably given you less reactivity as well. The manufacturers have erred on the side of caution, probably rightly so. By comparison the flu shot for last year's flu season had an effectiveness in the range of 50%. Of course, the thing that dings flu shot effectiveness is variant strains, while all the current COVID vaccines were designed from the original Wuhan strain (?), and likely have varying effectiveness against variant strains.