The other big issue with both these vaccines is the question of how long does the immune protection last. Both vaccines have been declared successful based on analysis two weeks after the second dose which is way to short but these are interim results.

This is an entirely new method of generating an immuneresponse and it is not known how long the immune response will last. Dr Fauci, I believe speculated they will have to be taken every year. The flu vaccine protects for around six months, its an open question as to how long these vaccines will protect.