As for the effectiveness of vaccines, I would like to say the following: no vaccine guarantees one hundred percent effectiveness, and no vaccine guarantees immortality and getting rid of other diseases that a person has. The main objective of vaccines is to reduce the incidence of coronavirus and, as a result, to reduce the number of complications and mortality among the population. Therefore, we should not pin unrealistic hopes on vaccination, but we should not underestimate the importance of vaccination for curbing the pandemic and returning to normal life.
There are two factors here. Different types of vaccines are available and they have efficacy ranging from 50% to 95%. Since the efficacy is not 100%, there is always a chance of contracting the COVID 19 infection even after full dose of the vaccine. But the advantage with those who got vaccinated is that even if they get the infection, it will be mild or asymptomatic, unlike the case with those who have not undergone vaccination.