No additional or new adverse events related to immunization with DTaP vaccines currently licensed for administration in the United States were found in an analysis conducted on the vaccines’ safety.
However, while reviewing data concerning adverse events following vaccination, researchers observed a disproportionate amount of administration errors related to these vaccines.
“Postmarketing observational studies have shown that the DTaP-containing vaccines have a good safety record,” Pedro L. Moro, MD, MPH, from the Immunization Safety Office, the Division of Healthcare Quality Promotion, National Center for Immunization and Respiratory Diseases at the CDC, and colleagues wrote. “However, these initial [Vaccine Adverse Event Reporting System (VAERS)] studies covered short periods of time and did not include the DTaP vaccines currently available in the U.S.; therefore, the safety information provided in these analyses are limited.”
To analyze the safety of DTaP vaccines that are currently licensed for use in the U.S., Moro and colleagues examined data from the VAERS, an unprompted reporting surveillance system concerning U.S. DTaP immunizations completed between Jan. 1, 1991, and Dec. 31, 2016. They also inspected accessible medical records for death reports and randomly selected reports that included nondeath serious events.
Figure 1. According to an researchers from the CDC, an analysis of the safety of DTaP vaccines demonstrated no new or additional adverse events related to immunization.
Once data were collected, Empirical Bayesian data mining was conducted to establish which adverse events were disproportionately reported following vaccination with DTaP.
Of the 50,157 reports of adverse events made after immunization, 87.7% involved concomitant administration of other vaccines. Adverse events were serious in 11.2% of reports, and most vaccinations occurred when children had a median age of 19 months (interquartile range, 35 months).
Death following immunization occurred in 844 infants. When the researchers examined available death certificates, autopsy reports and medical records (n = 725), SIDS was the most commonly reported cause of death (48.3%), with 62% of cases occurring in males and 90.9% occurring in children aged younger than 6 months.
Moro and colleagues observed that the most commonly reported adverse events to DTaP vaccination included injection site erythema (25.3%), pyrexia (19.8%), injection site swelling (15%), erythema (11.2%) and injection site warmth (9.6%).
Although no new or unanticipated adverse events were observed, when the researchers analyzed data using data mining, three types of vaccination errors were disproportionately reported. These errors included incorrect product formulation (n = 26; no reported adverse events), product quality issue (n = 23) and drug administered at inappropriate site (n = 19).
“The presence of vaccination errors calls for measurements to prevent their occurrence,” Moro and colleagues wrote. “The CDC and FDA will continue to monitor adverse events after DTaP vaccination in VAERS.” – by Katherine Bortz
Disclosures: The authors report no relevant financial disclosures.