P-53. Trends in Co-administration of Adult Vaccinations in the US Retail Pharmacy Setting
Authors: Sato Reiko , Yehoshua Alon , Vietri Jeffrey T , Hu Tianyan , Pond Taryn , Tort Maria J , Yang Jingyan , Welch Verna , Boikos Constantina , Deng Sen , Zheng Hao , Goswami Anchita , Agrawal Neha , Sharma Manvi 
Published: January 2025

Abstract

Background
Co-administering multiple vaccines during a single visit can be an efficient strategy to increase vaccine uptake and reduce missed vaccination opportunities. However, the extent to which this is a practice among US adults is not well documented. This study analyzed monthly trends in the co-administration of the US Advisory Committee on Immunization Practices (ACIP) recommended vaccines in the retail pharmacy setting and evaluated the most common combinations of co-administered vaccines.Figure 1:Number of vaccine co-administration by month (August 2018 - December 2023)

Methods
This was a retrospective study using the Adheris Pharmacy Dataset, which includes the majority of retail prescription volume. Adults aged ≥19 years with a record of receiving at least one ACIP-recommended vaccine at a retail pharmacy from August 2018 to December 2023 were included. Vaccine co-administration was defined as receiving two or more vaccines on the same day. Numbers and proportions of vaccine co-administrations were reported by month of administration and age group (19-49, 50-64, ≥65 years). Frequently co-administered vaccines were identified between August 2022 and December 2023. All descriptive analyses were conducted at the visit level.Figure 2:Proportion of vaccine co-administration by month (August 2018 - December 2023)

Results
Overall, there were 16.16 million visits with co-administration of vaccines during the study period, with a range of 0.81 million to 5.55 million annually (Figure 1). The proportions of monthly co-administrations showed an upward trend from 2018 (7.3%) to 2023 (32.6%), except for a marked decline in 2021 (Figure 2). Co-administration was observed year-round but was considerably higher between September and November across the years and age groups. The number of co-administrations increased with age (Figure 3). Among all co-administrations, influenza and COVID-19 vaccines combination was the most common across all age groups (50.0%-78.7%).Figure 3:Number of vaccine co-administration by age groups and month (August 2018 - December 2023)

Conclusion
There was an increase in the number and proportion of adult vaccines co-administered in 2022 and 2023 compared to previous years in all age groups. Co-administration of vaccines in the retail pharmacy setting has the potential to improve adult vaccination coverage.

Disclosures
Reiko Sato, PhD, Pfizer Inc: employee|Pfizer Inc: Stocks/Bonds (Private Company) Alon Yehoshua, PharmD, MS, Pfizer Inc: Employer|Pfizer Inc: Stocks/Bonds (Public Company) Jeffrey T. Vietri, PhD, Pfizer Inc.: Employment|Pfizer Inc.: Stocks/Bonds (Public Company) Tianyan Hu, PhD, Pfizer: Salary|Pfizer: Stocks/Bonds (Public Company) Taryn Pond, PharmD, Pfizer: Employee|Pfizer: Stocks/Bonds (Public Company) Maria J. Tort, PhD, Pfizer Inc: Stocks/Bonds (Public Company) Jingyan Yang, MHS, DrPH, Pfizer Inc: Employment|Pfizer Inc: Stocks/Bonds (Public Company) Verna Welch, PhD, MPH, Pfizer Inc.: Stocks/Bonds (Public Company) Constantina Boikos, MScPH, PhD, Pfizer: Full-time employee|Pfizer: Stocks/Bonds (Public Company) Anchita Goswami, MSc, Pfizer Inc.: Contracted research Neha Agrawal, MA, Pfizer Inc.: Contracted Research Manvi Sharma, RPh, MBA, PhD, Pfizer Inc.: Contracted research