The impact of universal live attenuated hepatitis A vaccines in Henan, China, 2005-2018

Abstract Objectives To analyze the effects of one dose of live attenuated hepatitis A vaccine in a developing country. Methods The reported cases of hepatitis A virus (HAV)infection from 2005 to 2018 in Henan province, China, were analyzed. Data of vaccinated children were assessed on the childhood immunization information management system. Questionnaire survey and blood sample collection were randomly conducted in six counties and districts of Henan province to analyze the prevalence of HAV lgG among the population aged 0-70 years. Results In 2008, Henan province began to expand its program on immunization, and children aged 18 months were given one dose of live attenuated hepatitis A vaccine (HepA-L). From 2005 to 2007, the HAV incidence remained steady at above 5000 cases per year and increased to 7489 in 2007. Since 2008, the HAV incidence decreased cumulatively from 4576 to 237 in 2018, indicating a 94.8% decrease, which was particularly pronounced among adolescents (98.2%). The proportion of hepatitis A cases in patients younger than 10 years continually decreased from 41.6% in 2012 to 3.8% in 2018. The reduction of reported cases older than 40 years was slower than that of children. In 2012, the proportion of hepatitis A cases older than 40 years was 27.6%, and continually increased to 69.2% (164/237) in 2018. The results of serological investigation showed that the 0-1.5-year age group had the lowest anti-HAV IgG prevalence (38.6%), which increased to 75.0% in the 4-6-year age group, covered by this immunization program. Conclusions The data indicated a large decrease in HAV infections in Henan province from 2008 onward in response to the introduction of a planned immunization program of HepA-L.