How many doses are required for the Hepatitis A vaccination series?

How many doses are required for the Hepatitis A vaccination series?

• A. One dose
• B. Two doses
• C. Three doses
• D. Four doses

Answer: (B)

Two doses are needed to achieve lasting protection. The first dose primes the immune system and gives protection within a few weeks, but antibody levels can wane over time in some people. The second dose, given several months later (typically about 6–12 months after the first), acts as a booster, boosting antibody levels to a level that provides durable protection for many years. While a single dose can offer some protection, it is not considered adequate for long-term immunity in routine vaccination.

Two doses are needed to achieve lasting protection. The first dose primes the immune system and gives protection within a few weeks, but antibody levels can wane over time in some people. The second dose, given several months later (typically about 6–12 months after the first), acts as a booster, boosting antibody levels to a level that provides durable protection for many years. While a single dose can offer some protection, it is not considered adequate for long-term immunity in routine vaccination.