@merpreb thank you for the explanation. Sounds like this will be an ongoing battle. With each vaccine i.e. each resistance the virus will have to mutate for survival. Mutation has been a way for survival for many years in living things. Unfortunately flu cases still exist and illnesses return with viruses we thought were completely wiped out. I know no vaccine is completely effective but how effective is the covid vaccine when there are surges of infection going on in this country and others? If the majority of the population has been vaccinated in some countries, why the surges? The unvaccinated are a small portion of the population. I would think there would be less cases. Has it really succeeded when vaccinated individuals can contract the infection and give it to others vaccinated or not? It may decrease the severity with symptoms but it doesn’t prevent the spread. It is scary to think that if one person out of 99 people did not get vaccinated that everyone is at risk for contracting covid infection. How effective is that vaccine? Even if everyone( all the population) was to get vaccinated that is no guarantee the virus won’t come back more aggressively with a variant. So where does it end?