Low immune response to hepatitis B vaccine among children in Dakar, Senegal.
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.
Unité de Recherche et d'Expertise en Epidémiologie des Maladies Emergentes, Institut Pasteur, Paris, France.
Marie-Anne
MA
Rey-Cuille
Abdoulaye
A
Seck
Richard
R
Njouom
Loïc
L
Chartier
Housseyn Dembel
HD
Sow
Mamadou
Amadou Sidy
AS
Ka
Mohamadou
M
Njankouo
Dominique
D
Rousset
Tamara
T
Giles-Vernick
Guillemette
G
Unal
Jean-Marie
JM
Sire
Benoît
B
Garin
François
F
Simon
Muriel
M
Vray
D003430:Cross-Sectional Studies; D005260:Female; D006509:Hepatitis B / Q000276:immunology*; D017325:Hepatitis B Vaccines / Q000276:immunology*; D006801:Humans; D007223:Infant; D008297:Male; D012675:Senegal; D014611:Vaccination / Q000706:statistics & numerical data
D017325:Hepatitis B Vaccines