Rate of hepatitis B seropositivity following mass vaccination in the Islamic Republic of Iran.

Universal vaccination of all neonates against hepatitis B virus has been implemented in the Islamic Republic of Iran since 1993. To evaluate the efficacy of the programme, 2 large seroepidemiologic surveys were conducted before and after mass vaccination on a representative sample of 1/1000 of the population. The overall seropositivity rate showed no significant decline between 1991 and 1999 but in the age group 2-14 years the rates reduced significantly (1.3% versus 0.8%, P < 0.05). Interestingly, we observed a significantly higher decline in hepatitis B virus carrier rate in rural (1.5% versus 0.6%) than urban areas (1.1% versus 0.9%). Universal vaccination significantly decreased the carrier rate among young children in this country.