Why do you think some vaccination procedures require a booster injection?

Some vaccination procedures require a booster injection to enhance and prolong the immune response generated by the initial dose. Over time, the immunity provided by the primary vaccination may wane, making individuals more susceptible to infection. Boosters help to reinforce the immune memory and ensure that the body can effectively recognize and combat pathogens, thereby maintaining a higher level of protection against diseases. Additionally, some vaccines target rapidly mutating viruses, necessitating booster shots to adapt to new strains.