Observational study of vaccine effectiveness 20 years after the introduction of universal hepatitis B vaccination in Tunisia

Vaccine. 2018 Sep 18;36(39):5858-5864. doi: 10.1016/j.vaccine.2018.08.038. Epub 2018 Aug 23.

Abstract

Objectives: The objectives of this study were to estimate the national prevalence of hepatitis B infection in Tunisia using data from a nationwide survey, to compare results with those obtained in 1996 survey and to evaluate the impact of vaccination twenty years after its introduction.

Methods: A National household-based cross sectional and serological survey was undertaken in 2015 from randomly selected districts using two-stage sampling. Data collection was performed using standardized and pretested questionnaires and collected blood samples were tested for markers of hepatitis B virus infection.

Results: National point prevalence of Hepatitis B surface antigen was 1.7% (95% CI [1.6-1.9%]). The highest prevalence was found in the Center and South regions with respectively 2.3% (95% CI [2.0-2.7%]) and 2.2% (95% CI [1.8-2.8%]). Vaccine effectiveness (VE) was 88.6% (95% CI [81.5-93.0%]) and was higher among population aged less than 20 years 96.1% (95% CI [70.1-99.5%]) than those aged more than 20 years 59.0% (95% CI [32.0-75.3%]). VE was 85.6% (95% CI [65.8-93.9%]) is hyper-endemic areas and 89.1% (95% CI [80.3-94.0%]) in meso-endemic and hypo-endemic areas.

Conclusions: The prevalence of Hepatitis B surface antigen decreased compared to previous estimations and classify Tunisia as a low endemic country as result to the introduction of vaccination since 1995.

Keywords: Hepatitis B; Seroprevalence; Tunisia; Vaccination impact.

Publication types

  • Observational Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Child
  • Cross-Sectional Studies
  • Family Characteristics
  • Female
  • Hepatitis B / prevention & control
  • Hepatitis B Antibodies / blood*
  • Hepatitis B Surface Antigens / immunology
  • Hepatitis B Vaccines / immunology*
  • Hepatitis B Vaccines / therapeutic use
  • Hepatitis B virus
  • Hepatitis B, Chronic / prevention & control
  • Humans
  • Immunization Programs
  • Male
  • Middle Aged
  • Prevalence
  • Rural Population
  • Seroepidemiologic Studies
  • Surveys and Questionnaires
  • Time Factors
  • Tunisia / epidemiology
  • Vaccination / statistics & numerical data*
  • Vaccine Potency*
  • Young Adult

Substances

  • Hepatitis B Antibodies
  • Hepatitis B Surface Antigens
  • Hepatitis B Vaccines