When should the second and third doses of the hepatitis B vaccine be administered?

When should the second and third doses of the hepatitis B vaccine be administered?

• A. You must have the second one in 6 months and the third in 1 year.
• B. You must have the second one in 1 month and the third in 6 months.
• C. You must have the second one in 1 year and the third the following year.
• D. You must have the second one in 2 weeks and the third in 1 month.

Answer: (B)

Hepatitis B vaccination is given as a three-dose series to build strong, lasting protection. The second dose should be given about one month after the first dose to boost the immune response, and the third dose should be given about six months after the first dose to complete the series and solidify long‑term immunity. For infants started at birth, the common pattern is 0, 1–2 months, and 6–18 months; for those starting later, the schedule is still 0, 1 month, and 6 months. Taking the second dose later than about one month, or waiting a year for the final dose, would leave a period without adequate protection and could reduce the sustained effectiveness of the vaccine.

Hepatitis B vaccination is given as a three-dose series to build strong, lasting protection. The second dose should be given about one month after the first dose to boost the immune response, and the third dose should be given about six months after the first dose to complete the series and solidify long‑term immunity. For infants started at birth, the common pattern is 0, 1–2 months, and 6–18 months; for those starting later, the schedule is still 0, 1 month, and 6 months. Taking the second dose later than about one month, or waiting a year for the final dose, would leave a period without adequate protection and could reduce the sustained effectiveness of the vaccine.