Because bacille Calmette-Guérin (BCG) vaccination elicits a TH2-type cytokine reaction, it has been suggested that the vaccine might protect against atopic disease. Krause and colleagues compared the risk of atopy in unselected groups of children who were vaccinated with BCG and children who were not vaccinated.
In Greenland, BCG vaccination was stopped in 1990, and restarted again in newborns in 1997. The authors studied children in four Greenland towns in 1998 and 2001, distributing among study participant families a self-administered questionnaire about sociodemographic variables and drawing a venous blood sample for IgE analysis.The authors compared the odds ratio (OR) for the prevalence of atopy in vaccinated versus unvaccinated children, and the OR for prevalence according to age.
The study group included 1,575 children eight to 16 years of age for whom information on BCG vaccination was available. Of these, 1,065 had been vaccinated, with exact information regarding dates of BCG vaccination available in all but three children. The adjusted risk of atopy was the same in BCG–vaccinated and unvaccinated children (OR, 1.03). There was no effect of age at BCG vaccination on risk of atopy. The IgE levels did not differ between BCG–vaccinated and unvaccinated children.
The authors conclude that these study results fail to support a hypothesis that BCG vaccination protects against the development of atopy.