CDC hepatitis B vaccine: what to know

Hepatitis B can affect the liver and may persist in the body. Vaccination prepares immune defences before exposure. The series may be advised for infants, children, adults at increased exposure risk, healthcare workers, household contacts, and some people with liver or immune conditions. Protection is assessed differently in certain clinical situations, so a blood test may be recommended after vaccination. Mild soreness or a short-lived fever can occur after an injection.

Bring your vaccination record to a clinic and ask which product and schedule apply. If a dose was delayed, book the next dose rather than restarting without advice. Tell the clinician about a serious reaction to a previous dose, current illness, pregnancy, or medicines that affect immunity. If you have had a possible exposure, seek advice quickly because vaccination and other measures may be time-sensitive. See Hepatitis B Vaccination for more detail.

Get prompt medical advice after a needlestick, contact with infected blood or body fluids, or sexual exposure. Seek urgent help for breathing difficulty, facial swelling, widespread hives, or collapse after vaccination. Fatigue or dark urine can occur with liver illness and warrants clinical review rather than assuming it is a vaccine effect.

Ask which schedule fits you, whether post-vaccination testing is needed, what to do after a missed dose, and how quickly to act after an exposure.