Final answer:
Immunization protocols can have varying validity periods. Some vaccines provide lifelong immunity, while others require periodic booster shots. For example, the tetanus vaccine needs a booster every 10 years, and the influenza vaccine is updated annually due to virus mutations.
Step-by-step explanation:
Immunization protocols are valid for different lengths of time depending on the specific vaccine and the disease it prevents. Some vaccines provide lifelong immunity, meaning they protect against the disease for the rest of a person's life. Other vaccines require periodic booster shots to maintain immunity. For example, the tetanus vaccine requires a booster every 10 years, while the influenza vaccine needs to be updated annually due to the virus's ability to mutate.