PLoS ONE (Jan 2012)

Low immune response to hepatitis B vaccine among children in Dakar, Senegal.

  • Marie-Anne Rey-Cuille,
  • Abdoulaye Seck,
  • Richard Njouom,
  • Loïc Chartier,
  • Housseyn Dembel Sow,
  • Mamadou,
  • Amadou Sidy Ka,
  • Mohamadou Njankouo,
  • Dominique Rousset,
  • Tamara Giles-Vernick,
  • Guillemette Unal,
  • Jean-Marie Sire,
  • Benoît Garin,
  • François Simon,
  • Muriel Vray

DOI
https://doi.org/10.1371/journal.pone.0038153
Journal volume & issue
Vol. 7, no. 5
p. e38153

Abstract

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HBV vaccine was introduced into the Expanded Programme on Immunization (EPI) in Senegal and Cameroon in 2005. We conducted a cross-sectional study in both countries to assess the HBV immune protection among children. All consecutive children under 4 years old, hospitalized for any reason between May 2009 and May 2010, with an immunisation card and a complete HBV vaccination, were tested for anti-HBs and anti-HBc. A total of 242 anti-HBc-negative children (128 in Cameroon and 114 in Senegal) were considered in the analysis. The prevalence of children with anti-HBs ≥ 10 IU/L was higher in Cameroon with 92% (95% CI: 87%-97%) compared to Senegal with 58% (95% CI: 49%-67%), (p<0.001). The response to vaccination in Senegal was lower in 2006-2007 (43%) than in 2008-2009 (65%), (p = 0.028). Our results, although not based on a representative sample of Senegalese or Cameroonian child populations, reveal a significant problem in vaccine response in Senegal. This response problem extends well beyond hepatitis B: the same children who have not developed an immune response to the HBV vaccine are also at risk for diphtheria, tetanus, pertussis (DTwP) and Haemophilus influenzae type b (Hib). Field biological monitoring should be carried out regularly in resource-poor countries to check quality of the vaccine administered.