Hepatitis A Issues and IAPCOI perspectives Dr Monjori Mitra Associate Professor Institute of Child Health Kolkata

Vaccination schedule Should depend on the seroepidemiology of the disease. Vaccine type – immunogenecity and safety of the vaccine Objective should be focussed on taking strategy to increase the coverage in endemic areas where disease is becoming a major complication.

Hepatitis A vaccines are all highly immunogenic Protective efficacy - 100% in adults after a single dose of vaccine within a month. Protective efficacy – 94% (95% confidence intervals: 82%–99%) following two doses in Thai population 1-16 yrs. Among approximately 1000 children aged 2–16 years, living in a highly disease-endemic community in the United States, the efficacy of one dose of vaccine was 100% (95% confidence intervals: 87%–100%). Inactivated Hepatitis A Vaccine WHO Position Paper 2000

Killed HAV vaccine cannot mimic the immune effect produced by natural infection of HAV. Since lifelong immunity following vaccination is very important in countries where childhood immunization is needed and where revaccination is not practical, the disadvantages of a killed vaccine are more conspicuous in China, with its high incidence of hepatitis A, huge population and low economic level. A better alternative to a killed vaccine is live, attenuated HAV vaccine. A programme aimed at developing such a vaccine was set up in China in Vaccine, Vol. 8, December 1990 Why ? Live attenuated Vaccine

Persistent Efficacy of live attenuated Hepatitis A Vaccine (H2) strain after a mass vaccination program

Persistence of anti-HAV antibody after 4 years – Multicentric study in India Time Since Vaccination Sampled subjects Tested subjects Anti –HAV antibody Positive (No.) Seroconversi on(%) GMT (mlU/mL) 0 months weeks months year year year year Unpublished: Faridi MMA, Shah N, Ghosh A, Sankaranarayanan VS, Mitra M

Anti-HAV IgG prevalence by City (n = 1612) Indian J Gastroenterol 2001

Seroprevalence of Hepatitis A across different states in India 2011 Interim report n = 934 % seropositive – 37.96%

Centre wise Seroprevalence of HAV:

Age wise seroprevalence in different centres

Seroprevalence based on SES in different centres

Two types of HAV vaccines are currently available internationally: 1)Formaldehyde-inactivated hepatitis A virus 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). 2) Live attenuated vaccines (based on H2 and LA-1 HAV strains). These vaccines are manufactured and used mainly in China and sporadically in the private sector in India. Hepatitis A Vaccine

Type of vaccine: Inactivated or live. 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). 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: All non-immune travellers to countries or areas at risk

Widely heterogenous pockets in epidemiology status in India Changing epidemiology Increased incidence of complicated hepatitis A with FHF Adequate evidence both India and China demonstrated single dose gives long term immunogenecity. Highly endemic countries in Europe have reduced HAV incidence by single dose of inactivated vaccine

Based on the current evidence to be presented by Dr Nitin Shah We need to decide One dose or two dose for live attenuated vaccine.