Measles, mumps and rubella infections and atopic disorders in MMR-unvaccinated and MMR-vaccinated children.

Vaccinations have been incriminated in the increase of atopic disorders. Especially the measles-mumps-rubella (MMR) vaccination is often refused by people having a notion that these infectious diseases are beneficial for a healthy development of a child's immune system. This practice endangers herd immunity and is the cause of repeated outbreaks. As the clinical course of infections and also its possible impact on the development of atopy may be different in vaccinated and unvaccinated individuals, we explored in vaccinated and unvaccinated children associations of MMR infection with atopic disorders. Using data from a previously conducted study on the relationship between the diphtheria-tetanus-pertussis-(inactivated) poliomyelitis vaccination in the first year of life and atopic disorders, the study population of 1872 8-12-yr-old was divided as children MMR-unvaccinated and children MMR-vaccinated in the first year of life. Within each group the association between MMR infections and atopic disorders (both as reported by the parents) was assessed. We found a statistically significant positive association between measles infection and 'any atopic disorder' [adjusted odds ratio, OR (95% confidence interval, CI): 1.77 (1.20-2.61)] in the MMR-vaccinated group, mainly because of the relationship with eczema. For rubella there was a negative association with eczema and food allergy in the unvaccinated group: adjusted OR (95% CI): 0.57 (0.38-0.85) and 0.23 (0.07-0.76), respectively. All other associations were not statistically significant. We found a positive relationship between measles infection and any atopy in a group of MMR-vaccinated children and a negative association between rubella infection and eczema and food allergy in unvaccinated children. However, we cannot conclude that these relationships are causal. The negative association with rubella may be an artefact. This study shows no evidence for any protective effects from MMR diseases for the development of atopy and therefore supports conclusions found elsewhere that childhood vaccinations do not cause atopy.