Country I was wondering that every vaccination we create doe

Country. I was wondering that every vaccination we create doesn\'t work on everyone. So how can we really vaccine work on 95% of people and not 5 %? Is this based off of one vaccination?

Solution

The efficacy of a vaccine is not same for all individuals in a population.Although in ideal circumstances, its efficacy is 100%, however in real scenario it may range from population to population (different ethinicities), their natural environment, genetic factors and even the disease attack rates etc. Therefore, all vaccines need a careful detailed trial for checking the vaccination efficiency in a random population. Although there is a lot of complexity and expense required for performinf such trials, especially for uncommon infectious where the sample size is relatively low.

A vaccine efficiency is mostly calculated as % reduction in disease incidence of a disease in a vaccinated group compared to an unvaccinated group under optimal conditions. This efficiency depends on a number of host factors such as age, Comorbidity- including frailty/function , genetic makeup of a person, prior exposure and time lapsed since vaccination. It also depends on the characteristics of vaccine itself, such as Mode of delivery, Live vs inactivated vaccine and its composition such as addition of adjuvant.

Thus, for more precise measurement of vaccine\'s effectiveness various cohort studies, case control studies and other screening methods are employed!