Hepatitis B Vaccine (3 doses) (age≥20)
This vaccine requires 2-4 doses to be fully effective:
- Adults ≥18 years old requiring rapid induction of protection (e.g. persons travelling to areas of high endemic city within 1 month prior to departure): 3 doses given at 0, 7 & 21 days may be used; 4th dose is recommended 12 months after the 1st dose.
People who have not received Hepatitis B vaccine. And people whose antibody level falls may need a booster.