Two types of HAV vaccines are currently available internationally:
- Formaldehyde-inactivated vaccines: Inactivated HAV vaccines are used in most countries. Monovalent inactivated HAV vaccines are available in paediatric dose (0.5 ml) for children aged >1 year to 15 years, and in adult dose (1 ml).
- Live attenuated vaccines (based on H2 or LA-1 HAV strains): These vaccines are manufactured and used mainly in China and sporadically in the private sector in India.
1. Inactivated hepatitis A vaccines are safe and highly effective. Traditionally, a two-dose schedule is recommended, particularly in travellers at substantial risk of contracting hepatitis A and in immunocompromised individuals. However, in healthy individuals, comparable effectiveness has been achieved with one single dose. Results from mathematical models indicate that, after completion of the primary two-dose series, anti-HAV antibodies may persist for 25 years or more. Serological testing to assess antibody levels after vaccination is not indicated.
A combination hepatitis A/typhoid (ViCPS) vaccine, administered as a single dose, confers high levels of protection against both these waterborne diseases.
A combination vaccine that provides protection against both hepatitis A and hepatitis B should be considered for travellers who may be exposed to both organisms (see under Hepatitis B vaccines).
2. The Chinese live attenuated hepatitis A vaccines have been shown to be safe and highly protective (95%) against clinical infection for at least 3 years.
Type of vaccine: Inactivated or live, both given i.m.
Number of doses: Inactivated vaccine: two; live vaccine: one
Schedule:Inactivated vaccine: two doses, the second dose normally 6 months after the first. If needed, this interval may be extended to 18–36 months). In healthy individuals, one single dose seems to be similarly efficacious. Live vaccine: one dose Minimum age for HAV vaccination is 1 year
boosters: May not be necessary
Contraindications: Hypersensitivity to previous dose
Adverse reactions:Inactivated vaccine: mild local reaction of short duration, mild systemic reaction Live vaccine: few reported
Before departure: Inactivated and live vaccines: protection is achieved 2–4 weeks after first dose. Given the long incubation period of hepatitis A (average 2–4 weeks), the vaccine can be administered up to the day of departure and still protect travellers.
Recommended for: Hepatitis A vaccination should be considered for individuals aged ≥1 year who are travelling to countries or areas with moderate to high risk of infection. Those at high risk of acquiring severe disease such as immunosuppressed patients and patients with chronic liver disease should be strongly encouraged to be vaccinated regardless of where they travel.
Special precautions: None