Delaying Vaccination Cuts Asthma Risk

Background

Early childhood immunizations have been viewed as promoters of asthma development by stimulating a TH2-type immune response or decreasing microbial pressure, which shifts the balance between TH1 and TH2 immunity.
Objective

Differing time schedules for childhood immunizations may explain the discrepant findings of an association with asthma reported in observational studies. This research was undertaken to determine whether timing of diphtheria, pertussis, tetanus (DPT) immunization has an effect on the development of childhood asthma by age 7 years.
Methods

This was a retrospective longitudinal study of a cohort of children born in Manitoba in 1995. The complete immunization and health care records of cohort children from birth until age 7 years were available for analysis. The adjusted odds ratio for asthma at age 7 years according to timing of DPT immunization was computed from multivariable logistic regression.
Results

Among 11, 531 children who received at least 4 doses of DPT, the risk of asthma was reduced to ½ in children whose first dose of DPT was delayed by more than 2 months. The likelihood of asthma in children with delays in all 3 doses was 0.39 (95% CI, 0.18-0.86).
Conclusion

We found a negative association between delay in administration of the first dose of whole-cell DPT immunization in childhood and the development of asthma; the association was greater with delays in all of the first 3 doses. The mechanism for this phenomenon requires further research.
Key words: DPT combination vaccine, childhood asthma, retrospective birth cohort, administrative health data
Abbreviations used: DaPT, Diphtheria, acellular pertussis, tetanus, DPT, Diphtheria, pertussis, tetanus, ICD-9, International Classification of Diseases, Ninth Revision, MIMS, Manitoba Immunization Monitoring System, MHSIP, Manitoba Health Services Insurance Program, OR, Odds ratio.

Source: Delay in diphtheria, pertussis, tetanus vaccination is associated with a reduced risk of childhood asthma, The Journal of Allergy and Clinical Immunology, Volume 121, Issue 3, Pages 626-631 (March 2008).

Put in plain English!

Researchers gave 11,531 babies four doses of the DPT vaccine.

5,000 of these babies started their jabs at 2 months old and 13.8% of them developed asthma.

In the babies who were 4 months old or older at the time of their first vaccination, there were only 5.9% who developed asthma.

The study also found a decreased incidence of asthma if the subsequent doses were delayed, but the strongest evidence for this was with the first dose.

The journal revealed that a staggering 12% of children go on to develop asthma after vaccination.

In spite of this evidence, they do not intend to change the vaccination schedule.

Parents of Unvaccinated Children Report Less Asthma

WOW! A study which looks at the health of the unvaccinated - this is 2nd study I have read on the subject. Doctors don't normally study the unvaccinated

Background

In the last 3 decades, there has been an unexplained increase in the prevalence of asthma and hay fever.
Objective

We sought to determine whether there is an association between childhood vaccination and atopic diseases, and we assessed the self-reported prevalence of atopic diseases in a population that included a large number of families not vaccinating their children.
Methods

Surveys were mailed to 2964 member households of the National Vaccine Information Center, which represents people concerned about vaccine safety, to ascertain vaccination and atopic disease status.
Results

The data included 515 never vaccinated, 423 partially vaccinated, and 239 completely vaccinated children. In multiple regression analyses there were significant (P < .0005) and dose-dependent negative relationships between vaccination refusal and self-reported asthma or hay fever only in children with no family history of the condition and, for asthma, in children with no exposure to antibiotics during infancy. Vaccination refusal was also significantly (P < .005) and negatively associated with self-reported eczema and current wheeze. A sensitivity analysis indicated that substantial biases would be required to overturn the observed associations.
Conclusion

Parents who refuse vaccinations reported less asthma and allergies in their unvaccinated children. Although this relationship was independent of measured confounders, it could be due to differences in other unmeasured lifestyle factors or systematic bias. Further research is needed to verify these results and investigate which exposures are driving the associations between vaccination refusal and allergic disease. The known benefits of vaccination currently outweigh the unproved risk of allergic disease.

Nashville, Tenn, London, United Kingdom, and Chicago, Ill
Key words: Immunization, asthma, allergic rhinitis, eczema, prevalence, cross-sectional survey
Abbreviations used: DTP, Diphtheria, tetanus, and pertussis, HiB, Haemophilus influenzae B, MMR, Measles, mumps, and rubella, NVIC, National Vaccine Information Center, RR, Rate ratio.

Source: The Journal of Allergy and Clinical Immunology, Volume 115, Issue 4, Pages 737-744 (April 2005).

VAN UK'S Comment: I have no doubt that lack of antibiotics and antipyretics would also decrease asthma and is a factor in addition to non-vaccination, however, other studies have linked vaccination with asthma, so this shouldn't be ignored.

As a mother of unvaccinated children I can say that if my child was having difficulty breathing, I most certainly would get him seen by a doctor, as would other mothers, so I don't think the low asthma rate is due to not reporting to the GP