Vaccines, basically, help immune system to develop and retain Memory-B cells against a pathogen, without the need of contracting any life-threatening disease. Sometimes more than one dose of a vaccine may be required to develop a long-lasting immunity.
That is why we needed several booster doses for polio. Vaccines have come a long way. While inactivated pathogens were used during the early vaccines, the modern vaccines use just the genetic sequences for any specific part of the pathogen (epitope), which is good enough to generate antibodies and Memory-B cells.
Thus, the actual pathogen or its fragment is not used even indirectly. The world is free of diseases like smallpox and polio primarily due to vaccines.
Is There a Vaccine Hesitancy for COVID-19 Vaccines?
Vaccine hesitancy is not a new phenomenon. At different times and places, people have avoided vaccines due to personal reasons and beliefs, misinformation, and socio-political issues, including anti-vaccination campaigns.
The…