Study Further Demonstrates Pertussis Vaccine Safety

A new study revealed no new or unexpected safety concerns associated with the diphtheria, tetanus, and acellular pertussis vaccine (DTaP). Data were analyzed between 1991 and 2016 from the Vaccine Adverse Event Reporting System (VAERS).¹ The first DTaP vaccine was approved by the FDA in 1991 and was recommended in place of the whole cell pertussis (DTwP) for the fourth and fifth doses of the recommended series. There were safety concerns associated with DTwP, which included febrile seizures, and acute encephalopathy.

Study Methods

The VAERS database was searched for reports after DTaP vaccination for any of the currently licensed vaccines.² Non-United States reports, and duplicate reports were excluded from the study. Death reports after the DTaP vaccine were reviewed by a physician. The VAERS was searched for reports of anaphylaxis, and there was a clinical review conducted in a sample of 5% of non death serious reports after DTaP administration.²

Study Results

There were 50,157 reports involving DTaP in VAERS during the study period.² Additionally, the DTaP vaccine was administered with 1 or more vaccines in 87.7% of reports. Among the vaccine reports, 11.2% were classified as serious, including 1.7% death reports. The most common cause of death was sudden infant death syndrome (SIDS). The most common reported adverse effects were injection site erythema (25.3%), fever (19.8%), injection site swelling (15%), erythema (11.2%), and injection site warmth (9.6%).²

Study Application to Clinical Practice

It is important to remember that VAERS cannot usually assess if a vaccine caused an adverse effect, but it is a useful tool for identifying possible safety issues. Pharmacists should report adverse effects associated with DTaP to VAERS. The study revealed that most adverse effects reported with the DTaP vaccine were not serious. Numerous studies have demonstrated that vaccines do not cause SIDS. Infants receive the DTaP vaccine series during the timeframe that SIDS most commonly occurs, so it is likely a coincidental finding.

Pharmacists can play an important role in educating parents on the importance of staying up-to-date on the DTaP vaccine serious for their children. The CDC’s Advisory Committee on Immunization Practices recommends that infants and children receive a 5-dose series of DTaP at ages 2, 4, and 6 months, 15-18 months, and 4-6 years.³ Pregnant women should receive the tetanus, diphtheria, and pertussis (Tdap) vaccination at 27-36 weeks (third trimester) of pregnancy to allow for the optimal transfer of protective antibodies from mothers to their babies.³ Additionally, the Tdap vaccine should be given to pregnant women during each pregnancy. Infants do not begin their own vaccine series against pertussis until approximately 2 months of age, so maternal vaccination is extremely important.

References

• American Academy of Pediatrics. Study analyzes the safety of DTaP vaccine as reported to national data system. https://healthychildren.org/English/news/Pages/Study-Analyzes-the-Safety-of-DTaP-Vaccine-as-Reported-to-National-Data-System.aspx. Accessed June 5, 2018.
• Moro PL, Perez-Vilar S, Lewis P, et al. Safety surveillance of diphtheria and tetanus toxoids and acellular pertussis (DTaP) vaccines. Pediatrics. 2018;142(1):e20174171.
• Liang JL, Tiwari T, Moro P, et al. Prevention of pertussis, tetanus, and diphtheria with vaccines in the United States: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep 2018;67(No.RR-2):1-44.DOI:http://dx.doi.org/10.15585/mmwr.rr6702a1.