Why do people need to repeatedly get some vaccines

Every vaccine ever created has to take many variables into consideration, he explained, including the individual pathogen or bug; how our immune systems respond to it; what parts of the bug can be used to generate an immune response that is protective in nature; and also how long that response will last. Because that equation is notably complex, sometimes a second (or third) dose is a good idea.

- in order to remain healthy and avoid any diseases/illnesses

- health plan by the government. (Where the government sets up a thing where people of a certain age group have to take a vaccine)