A vaccine will not work if the immune system does not generate antibodies after exposure to a virus.

“if we get infected with corona virus and then we can get infected with chrono virus again if we don't have immunity to corona virus after we get infected with corona virus then a vaccine is not going to work and we are going to be in a world of hurt but I don't think that that's really how the immune system works as a model system has worked in the past or will work with this virus if we get exposed to something our immune system will generate antibodies that is how vaccines work that is how our immune system works if that doesn't happen then we are in a novel situation I think that is very very unlikely”