August 9, 2005

Kids’ Shots Don’t Make Other Ills More Likely

NEW YORK -- The numerous childhood vaccines administered today do not increase the risk of kids being hospitalized with infections that are not covered by the shots, a population-based study suggests.

In fact, some evidence indicates that vaccination may have protective effects against non-targeted infections.

Anders Hviid and colleagues explain in this week's Journal of the American Medical Association that there has been some concern that the increasing complexity of childhood vaccine schedules could skew the immune system, leading to increased risk of infection by untargeted organisms.

To see if there's anything to that notion, Hviid and colleagues at Statens Serum Institut in Copenhagen evaluated data from the Danish Civil Registration System for all children born in Denmark from 1990 through 2001.

The cohort included more than 800,000 children, among whom there were 84,317 hospitalizations for infectious diseases. These include acute upper respiratory tract infection, viral and bacterial pneumonia, bloodstream sepsis, viral infections of the brain or spinal cord, bacterial meningitis and diarrhea.

The only statistically significant adverse association was between the Hib vaccine and acute upper respiratory tract infection. For every 100 such infections in vaccinated children, there were 105 in unvaccinated children. However, the team notes, "The association is unlikely to be causal."

In contrast, their data suggested 15 protective associations.

"Our results do not support the hypothesis of increased risk of nontargeted infectious disease hospitalization after childhood vaccination," the researchers conclude.

SOURCE: Journal of the American Medical Association, August 10, 2005.