Lisa Hefele1, Souphaphone Vannachone2, Vilaysone Khounvisith3, Phonethipsavanh Nouanthong3, Somphou Sayasone2, Sengchang Kounnavong2, Phetsavanh Chanthavilay2, Claude P Muller4, Antony P Black3. 1. Lao-Lux Laboratory, Institut Pasteur du Laos, Vientiane, Lao Democratic People's Republic; Department of Infection and Immunity, Luxembourg Institute of Health, Esch-sur-Alzette, Luxembourg. Electronic address: lisa.hefele@lih.lu. 2. Lao Tropical and Public Health Institute, Vientiane, Lao Democratic People's Republic. 3. Lao-Lux Laboratory, Institut Pasteur du Laos, Vientiane, Lao Democratic People's Republic. 4. Lao-Lux Laboratory, Institut Pasteur du Laos, Vientiane, Lao Democratic People's Republic; Department of Infection and Immunity, Luxembourg Institute of Health, Esch-sur-Alzette, Luxembourg.
Abstract
OBJECTIVES: Hepatitis B is endemic in Lao PDR with 8-10% of the adult population being chronically infected. We investigated the impact of hepatitis B vaccination on infection in adolescents born shortly before and after the introduction of the vaccine in 2001. METHODS: 779 students from Vientiane Capital and Bolikhamxay province were tested for HBV markers by ELISA. Socio-demographic information was collected with a standardized questionnaire. Predictors/risk factors for seroprotection or exposure to hepatitis B infection were assessed by bivariate and multivariable analyses. RESULTS: The prevalence of a serological vaccination profile increased significantly after the introduction of the vaccine (13.2%-21.9%, p < 0.05, in Vientiane; 3.0%-19.7%, p < 0.001, in Bolikhamxay), which translated into at least a 2-times lower prevalence of past infection. In logistic regression, older students in Bolikhamxay were less likely to be vaccinated and more likely to have been infected by HBV in the past. CONCLUSION: Even though this study documented a sizable and lasting reduction in past hepatitis B infections in adolescents born after the introduction of infant hepatitis B vaccination, the overall levels of protective anti-HBs were low and warrant at least the introduction of a booster for adolescents. Furthermore, we suggest improving the coverage of the hepatitis B birth dose.
OBJECTIVES:Hepatitis B is endemic in Lao PDR with 8-10% of the adult population being chronically infected. We investigated the impact of hepatitis B vaccination on infection in adolescents born shortly before and after the introduction of the vaccine in 2001. METHODS: 779 students from Vientiane Capital and Bolikhamxay province were tested for HBV markers by ELISA. Socio-demographic information was collected with a standardized questionnaire. Predictors/risk factors for seroprotection or exposure to hepatitis B infection were assessed by bivariate and multivariable analyses. RESULTS: The prevalence of a serological vaccination profile increased significantly after the introduction of the vaccine (13.2%-21.9%, p < 0.05, in Vientiane; 3.0%-19.7%, p < 0.001, in Bolikhamxay), which translated into at least a 2-times lower prevalence of past infection. In logistic regression, older students in Bolikhamxay were less likely to be vaccinated and more likely to have been infected by HBV in the past. CONCLUSION: Even though this study documented a sizable and lasting reduction in past hepatitis B infections in adolescents born after the introduction of infanthepatitis B vaccination, the overall levels of protective anti-HBs were low and warrant at least the introduction of a booster for adolescents. Furthermore, we suggest improving the coverage of the hepatitis B birth dose.
Authors: Lisa Hefele; Antony P Black; Trinh Van Tan; Nguyen Tri Minh; Nguyen Duc Hoang; Siriphone Virachith; Claude P Muller; Judith M Hübschen; Paula Russell; Josefin Bartholdson Scott; Chau Nguyen Ngoc Minh; Tran Vu Thieu Nga; Stephen Baker Journal: PLoS Negl Trop Dis Date: 2021-12-13
Authors: Lisa Hefele; Jana Lai; Keoudomphone Vilivong; Toukta Bounkhoun; Valin Chanthaluanglath; Anisone Chanthongthip; Anne Balloch; Antony P Black; Judith M Hübschen; Fiona M Russell; Claude P Muller Journal: PLoS One Date: 2022-09-15 Impact factor: 3.752