Influenza vaccination is administered throughout the influenza disease season, even as late as March. Given such timing, what is the value of vaccinating the population earlier than currently being practiced?
We used real data on when individuals were vaccinated in Allegheny County, Pennsylvania, and the following 2 models to determine the value of vaccinating individuals earlier (by the end of September, October, and November): Framework for Reconstructing Epidemiological Dynamics (FRED), an agent-based model (ABM), and FluEcon, our influenza economic model that translates cases from the ABM to outcomes and costs [health care and lost productivity costs and quality-adjusted life-years (QALYs)]. We varied the reproductive number (R0) from 1.2 to 1.6.
Applying the current timing of vaccinations averted 223,761 influenza cases, $16.3 million in direct health care costs, $50.0 million in productivity losses, and 804 in QALYs, compared with no vaccination (February peak, R0 1.2). When the population does not have preexisting immunity and the influenza season peaks in February (R0 1.2–1.6), moving individuals who currently received the vaccine after September to the end of September could avert an additional 9634–17,794 influenza cases, $0.6–$1.4 million in direct costs, $2.1–$4.0 million in productivity losses, and 35–64 QALYs. Moving the vaccination of just children to September (R0 1.2–1.6) averted 11,366–1660 influenza cases, $0.6–$0.03 million in direct costs, $2.3–$0.2 million in productivity losses, and 42–8 QALYs. Moving the season peak to December increased these benefits, whereas increasing preexisting immunity reduced these benefits.
Even though many people are vaccinated well after September/October, they likely are still vaccinated early enough to provide substantial cost-savings.
*Public Health Computational and Operations Research, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
†Pittsburgh Supercomputing Center, Carnegie Mellon University
‡RTI International, Research Triangle Park, NC
§University of Pittsburgh School of Medicine, Pittsburgh, PA
Supported by Cooperative Agreement FOA IP11-003, U01IP000467, funded by the Centers for Disease Control and Prevention (CDC), Agency for Healthcare Research and Quality (AHRQ) 1R01HS02331701, NICHD/NIH 5U54HD07072503, and the Bill and Melinda Gates Foundation.
R.K.Z. discloses that he has clinical research grants from Pfizer and SanofiPasteur. The remaining authors declare no conflict of interest.
Reprints: Bruce Y. Lee, MD, MBA, Public Health Computational and Operations Research, Johns Hopkins Bloomberg School of Public Health, 855 N. Wolfe Street, Suite 600, Baltimore, MD 21205. E-mail: email@example.com.