Analía Urueña1, Jorge E González, Analía Rearte, María E Pérez Carrega, Rogelio Calli, María F Pagani, Andrea Uboldi, Rosalía Vicentín, Patricia Caglio, María C Cañero-Velasco, Angela Gentile, Margarita Ramonet, Carla Vizzotti. 1. From the *Dirección Nacional de Control de Enfermedades Inmunoprevenibles, Ministerio de Salud de la Nación, C.A.B.A., Argentina; †Laboratorio Nacional de Referencia de Hepatitis Virales, INEI-ANLIS "Dr. Carlos Malbrán", C.A.B.A., Argentina; ‡Dirección de Epidemiología del Ministerio de Salud Pública de la Provincia de Tucumán, Tucumán, Argentina; §Servicio de Gastroenterología. Hospital del Niño Jesús de Tucumán, Tucumán, Argentina; ¶Programa Ampliado de Inmunizaciones, Ministerio de Salud de la Provincia de Santa Fe, Santa Fe, Argentina; ‖Servicio de Gastroenterología, Hospital de Niños Dr. Orlando Alassia, Santa Fe, Argentina; **Hospital Nacional Prof. Dr. Alejandro Posadas, Provincia de Buenos Aires, Argentina; ††Hospital de Niños de San Justo, Provincia de Buenos Aires, Argentina; ‡‡Hospital de Niños Ricardo Gutiérrez, C.A.B.A. Argentina; and §§Comisión Nacional de Hepatología, Sociedad Argentina de pediatría, C.A.B.A., Argentina.
Abstract
BACKGROUND: Single-dose hepatitis A virus (HAV) vaccination was implemented in all Argentinean children 12 months of age in 2005. Previous studies demonstrated high prevalence of protective antibody response 4 years after single-dose vaccination. This study assessed long-term seroprotection against HAV after vaccination. METHODS: Children who received 1 dose of HAV vaccine at 1 year of age at least 6 years before enrollment were included at 5 centers in Argentina between 2013 and 2014. Demographic and socioeconomic characteristics were collected through a questionnaire. Blood samples were tested for anti-HAV antibodies. Antibody values ≥10 mIU/mL were considered seroprotective. Logistic regression analysis was performed to evaluate the association between demographic and socioeconomic variables and seroprotection. RESULTS: A total of 1088 children were included, with a median postvaccination interval of 7.7 years (range 6.3-9.2 years). Of these children, 97.4% (95% confidence interval: 96.3%-98.3%) had protective antibodies against HAV. No association between demographic or socioeconomic variables and seroprotection was found. Geometric mean concentration of antibody levels against HAV was 170.5 mUI/mL (95% confidence interval: 163.2-178.2 mUI/mL). CONCLUSIONS: Single-dose universal hepatitis A immunization in 1-year-old children resulted in sustained immunologic protection for up to 9 years in Argentina. These findings, along with the low current disease burden, confirm the success of the intervention.
BACKGROUND: Single-dose hepatitis A virus (HAV) vaccination was implemented in all Argentinean children 12 months of age in 2005. Previous studies demonstrated high prevalence of protective antibody response 4 years after single-dose vaccination. This study assessed long-term seroprotection against HAV after vaccination. METHODS:Children who received 1 dose of HAV vaccine at 1 year of age at least 6 years before enrollment were included at 5 centers in Argentina between 2013 and 2014. Demographic and socioeconomic characteristics were collected through a questionnaire. Blood samples were tested for anti-HAV antibodies. Antibody values ≥10 mIU/mL were considered seroprotective. Logistic regression analysis was performed to evaluate the association between demographic and socioeconomic variables and seroprotection. RESULTS: A total of 1088 children were included, with a median postvaccination interval of 7.7 years (range 6.3-9.2 years). Of these children, 97.4% (95% confidence interval: 96.3%-98.3%) had protective antibodies against HAV. No association between demographic or socioeconomic variables and seroprotection was found. Geometric mean concentration of antibody levels against HAV was 170.5 mUI/mL (95% confidence interval: 163.2-178.2 mUI/mL). CONCLUSIONS: Single-dose universal hepatitis A immunization in 1-year-old children resulted in sustained immunologic protection for up to 9 years in Argentina. These findings, along with the low current disease burden, confirm the success of the intervention.
Authors: Noele P Nelson; Mark K Weng; Megan G Hofmeister; Kelly L Moore; Mona Doshani; Saleem Kamili; Alaya Koneru; Penina Haber; Liesl Hagan; José R Romero; Sarah Schillie; Aaron M Harris Journal: MMWR Recomm Rep Date: 2020-07-03