DTP (or DTaP) Immunization and
allergic or autoimmune diseases:
Is there a connection?

Recently questions have been asked as to whether there is a potential association between  immunization with the DTP (or DTaP) vaccines (the pertussis component) and increased  incidence of  asthma and other auto-immune disorders.

Uncontrolled surveys such as by Odent,(1)  cross-sectional studies such as by Hurwitz,(2) and small population reviews such as by Yoneyama (3), have suggested a possible association between DTP and autoimmune conditions.

(For a detailed critique of Hurwitz and Morgenstern's study CLICK HERE!)

These surveys and cross-sectional studies have suffered from lack of adequate controls, high confidence of error margins, small populations, and other short-comings that prevent legitimate cause-and-effect determinations.

However, when careful, prospective, randomized studies have been conducted the outcomes have been uniformly, and without exception, quite different.  Following are some examples:

Pershagen found ". . . randomized clinical trials involving both whole cell and acellular pertussis vaccines have failed to show any enhancement of atopic manifestations in children." (4)

Henderson concluded  ". . .comparisons of the defined wheezing illnesses in vaccinated and non-vaccinated children showed no significant association between pertussis vaccination and any of the wheezing outcomes regardless of stratification for parental asthma or allergy. "  And that "No evidence was found that pertussis vaccination increases the risk of wheezing illnesses in young children." (5)

Ryan, et al note "It has been suggested that childhood immunization with Th2-inducing vaccines may predispose some children to atopic disease. Although we found that pertussis toxin (PT)-specific IgE was significantly increased after booster immunization in both atopic and non-atopic children, the levels of IgE to common allergens and the prevalence of positive skin prick test were unaffected by the booster vaccination. Thus, despite the enhancement of type-2 responses to B. pertussis antigens, booster vaccination with Pa does not appear to be a risk factor for allergy." (6)

Gifford studied atopic and non-atopic children for Ragweed sensitivity following pertussis booster immunization and found "None of the parameters changed significantly in either group regardless of the type of immunization administered." (7)

In another major randomized study Nilsson found "We found no support for a drastic increase in allergic manifestations after pertussis vaccination. There was a positive association between whooping cough and asthma by 2 1/2 years of age. There seems to be little reason to withhold pertussis vaccination from infants, irrespective of family history of allergy." (8)

In a follow-up study Nilsson et al added a structured interview to all families in a double-blind study of pertussis vaccines and childhood allergic disease.  Sweden's pertussis immunization program was interrupted from 1979 to the 1990's.  In 1992 a double-blind study was done examining three different DTP vaccines with a fourth group receiving a non-pertussis vaccine as a placebo control.  The children were followed for 21/2 years. 
The results:  "We found no significant differences between the DTP vaccination groups in the proportions which reported wheezing, itchy rash, or sneezing.   After exclusion of children with verified pertussis, the proportions were almost identical.  These results suggest that there is no reason to withhold pertussis vaccinations because of fear of subsequent asthma or
allergy."  (9)

CONCLUSION:
The current controversy regarding pertussis vaccine and subsequent allergies is reminiscent of  allegations two decades ago that DTP was associated with SIDS.   Subsequent research has clearly and irrefutably clarified that no such association exists.  (See the REVIEW  of the Hurwitz study).  

Absolute final answers are not yet available, and research continues.  The weight of present quality evidence increasingly casts doubt on any association between pertussis (DTP, DTaP) vaccine and subsequent development of allergies, asthma or atopic diseases in vaccine recipients.

REFERENCES:

1.  Odent MR, Culpin EE, Kimmel T.Pertussis vaccination and asthma: is there a link?
       JAMA. 1994 Aug 24-31;272(8):592-3. (Letter)

2.  Hurwitz EL, Morgenstern H.
     Effects of diphtheria-tetanus-pertussis or tetanus vaccination on allergies and
     allergy-related respiratory symptoms among children and adolescents in the United States.
     J Manipulative Physiol Ther. 2000 Feb;23(2):81-90.

3.  Yoneyama H, Suzuki M, Fujii K, Odajima Y.
   [The effect of DPT and BCG vaccinations on atopic disorders].
    Arerugi. 2000 Jul;49(7):585-92. Japanese.

4. Pershagen G
    Can immunization affect the development of allergy?
    Pediatr Allergy Immunol 2000;11 Suppl 13:26-8

5.  Henderson J.  Pertussis vaccination and wheezing illnesses in young children:
     prospective cohort study. The Longitudinal Study of Pregnancy and Childhood Team.  
     BMJ 1999 May 1;318(7192):1173-6

6. Ryan EJ.   Booster immunization of children with an acellular pertussis vaccine enhances
    Th2 cytokine production and serum IgE responses against pertussis toxin but not against
    common allergens.  Clin Exp Immunol 2000 Aug;121(2):193-200

7. Gifford CJ.
    Pertussis booster vaccination and immediate hypersensitivity.
   Ann Allergy 1985 Jun;54(6):483-5

8 Nilsson L. et al.
   A randomized controlled trial of the effect of pertussis vaccines on atopic disease.
   Arch Pediatr Adolesc Med 1998 Aug;152(8):734-8

9. Nilsson L et al

                 Lack of association between pertussis vaccination and symptoms of asthma and allergy
                 JAMA 1996 Mar 13  275(10):760.