From Hay fever not linked to kids’ immunizations:
The relatively few children that had not been vaccinated for diphtheria, tetanus and pertussis (DTP) had virtually the same hay fever risk as the large percentage that completed DTP vaccinations by their fifth month.As for measles, mumps and rubella (MMR) immunization, unvaccinated children had slightly lower chances of having hay fever than those vaccinated in month 14, although the difference was not statistically significant.
The investigators found that with both DPT and MMR vaccination, children that got their shots late had about a 40 percent reduced risk of hay fever. The team suggests that this ‘may be explained by a third factor causing both postponement and reduced risk, such as intercurrent febrile illness.’
Cook and colleagues also looked at anti-TB immunization with BCG vaccine, which is thought to protect against becoming allergic. However, that’s not what they found. ‘Immunization with BCG by age 2 was associated with an increased risk of hay fever,’ they report.