1393. Factors Associated with Co-administration of Pentavalent DTaP-IPV/Hib and Monovalent Hepatitis B Vaccine in the United States (US)
Authors: Petigara Tanaz , Chen Ya-Ting , Liu Zhiwen , Goveia Michelle , Johnson David , Marshall Gary S 
Published: January 2021

Abstract

Background
The US vaccination schedule includes DTaP, IPV, Hib and HepB doses in the first 6 months of life. A previous analysis found variability in the timing of HepB doses in infants receiving DTaP-IPV/Hib. We explored factors associated with co-administration of DTaP-IPV/Hib and HepB on the same day.

Methods
This was a retrospective study using the MarketScan® commercial claims and encounters database. Infants born from 1 July 2010 - 30 June 2016, continuously enrolled in an insurance plan for ≥ 13 months and receiving ≥ 3 DTaP-IPV/Hib doses were included.
Infants were assessed for HepB claims relative to the first and third DTaP-IPV/Hib doses. Because a HepB birth dose was assumed, the first HepB claim from 29 - 169 days following birth was counted as Dose 2, and the second claim from 170 days - 12 months as Dose 3. Associations between demographic, provider, and insurance characteristics, receipt of other pediatric vaccines, and co-administration of DTaP-IPV/Hib and HepB were analyzed using multivariate logistic regression.

Results
Among 165,553 infants who received a first DTaP-IPV/Hib dose, 60.7% received HepB Dose 2 on the same day. Among 162,217 infants who received a third DTaP-IPV/Hib dose, 45.1% received HepB Dose 3 on the same day.
Infants in the Northeast were less likely (OR=0.38, 95%CI=0.36-0.39), while those in the West were more likely (OR=1.41, 95%CI=1.36-1.46) than infants in the South to receive the first dose of DTaP-IPV/Hib and HepB Dose 2 on the same day. Infants vaccinated by pediatricians (OR=0.54, 95%CI=0.53-0.55) were less likely to receive the first dose of DTaP-IPV/Hib and HepB Dose 2 on the same day compared to infants vaccinated by family physicians. Infants who received PCV on the same day as the first dose of DTaP-IPV/Hib were more likely to receive HepB Dose 2 (OR=6.96, 95%CI=6.30-7.70) that day. These factors were also associated with co-administration of the third dose of DTaP-IPV/Hib and HepB Dose 3.

Conclusion
Differences in co-administration of DTaP-IPV/Hib and HepB were associated with region of residence, provider type and co-administration of PCV. The reasons underlying these differences merit exploration. A hexavalent vaccine containing DTaP, IPV, Hib, and HepB could improve timeliness of HepB vaccination, while reducing the number of injections during infancy.

Disclosures
Tanaz Petigara, PhD, Merck & Co., Inc. (Employee, Shareholder) Ya-Ting Chen, PhD, Merck & Co., Inc. (Employee, Shareholder) Zhiwen Liu, PhD, Merck & Co., Inc., (Employee) Michelle Goveia, MD, Merck & Co., Inc (Employee, Shareholder) David Johnson, MD, MPH, Sanofi Pasteur (Employee, Shareholder) Gary S. Marshall, MD, GlaxoSmithKline (Consultant, Scientific Research Study Investigator)Merck (Consultant, Scientific Research Study Investigator)Pfizer (Consultant, Scientific Research Study Investigator)Sanofi Pasteur (Consultant, Grant/Research Support, Scientific Research Study Investigator, Honorarium for conference lecture)Seqirus (Consultant, Scientific Research Study Investigator)