Does vaccine type impact DTaP adherence?

Vaccine guidelines currently recommend the 3+1 diphtheria, tetanus, and acellular pertussis (DTaP) vaccine series for infants and toddlers, but coverage and timeliness of receiving the vaccines continues to be at less than optimal levels in the United States. A poster presentation at the virtual 2020 ID Week presented the results of a study that compared coverage and timeliness between DTaP-containing combination vaccines (ie, quadrivalent/pentavalent) and stand-alone vaccines (ie, trivalent).¹

The researchers developed a cohort of children who were born between 2009 and 2016 with >24 months of continuous enrollment from birth and a record of > 1 DTaP vaccine being administered. It was created using the Optum de-identified Clinformatics Data Mart database. The children were labelled by DTaP vaccine uptake: combination vaccines only, stand-alone vaccines only, or a mixture of both. Primary outcome for the study was completing a 4-dose series of DTaP by the time the patient was 20 months of age.

The cohort included 412,450 children, comprised of 200,568 girls (48.6%) and 211,882 boys (51.4%). Among these children, 167,091 were administered only combination vaccines; 61,342 children received the stand-alone vaccine only; and 184,017 members of the cohort were administered a mixture of stand-alone and combination vaccine doses. The researchers found that the completion of the 4-dose series was highest in children who had only received the combination vaccine (75.5%). It was slightly less for a mixture of vaccine types (72.7%) and much less for children who had only received the stand-alone vaccine (54.5%). When compared to patients who only received the stand-alone vaccine, the adjusted odds for completion were roughly 2.5 times higher in those who received a mixture of vaccines (odds ratio [OR] = 2.54 [2.49, 2.59]) and 2.9 times higher in those who received the combination vaccine.

The researchers concluded that a combination vaccine with DTaP was tied to significantly higher coverage and timeliness of vaccine receipt. Further research should look at greater understanding of the determinants of infant vaccine adherence.

Research

1. Loiacono M, Pool V, Van Aalst R. DTaP-containing combination vaccines use and adherence to the recommended infant-toddler vaccination series among privately insured children in the US. Presentation presented at the: 2020 virtual ID Week.