• FluTrackers.com Inc. does not provide medical advice. Information on this web site is collected from various internet resources, and the FluTrackers board of directors makes no warranty to the safety, efficacy, correctness or completeness of the information posted on this site by any author or poster. The information collated here is for instructional and/or discussion purposes only and is NOT intended to diagnose or treat any disease, illness, or other medical condition. Every individual reader or poster should seek advice from their personal physician/healthcare practitioner before considering or using any interventions that are discussed on this website. By continuing to access this website you agree to consult your personal physican before using any interventions posted on this website, and you agree to hold harmless FluTrackers.com Inc., the board of directors, the members, and all authors and posters for any effects from use of any medication, supplement, vitamin or other substance, device, intervention, etc. mentioned in posts on this website, or other internet venues referenced in posts on this website.
  • We are not asking for any donations. Do not donate to any entity who says they are raising funds for us.

Vaccine . Impact of reminder messages, with and without financial incentives, on influenza vaccination: A randomized trial in a California health sy

tetano

Editor, Senior Moderator
Vaccine


. 2026 Jan 27:75:128263.
doi: 10.1016/j.vaccine.2026.128263. Online ahead of print.
Impact of reminder messages, with and without financial incentives, on influenza vaccination: A randomized trial in a California health system

Tom Y Chang[SUP] 1 [/SUP], Mireille Jacobson[SUP] 2 [/SUP], Manisha Shah[SUP] 3 [/SUP], Rajiv Pramanik[SUP] 4 [/SUP], Samir B Shah[SUP] 4 [/SUP]


Affiliations
Abstract

Vaccine hesitancy has risen in the aftermath of the COVID-19 pandemic, raising new concerns about declining uptake of routine immunizations like the seasonal flu shot. Although past studies have shown that financial incentives can boost vaccination, it is unclear whether these strategies remain effective in today's more skeptical environment. To examine this, we conducted a three-arm randomized controlled trial in a racially and economically diverse county health system in Northern California. The trial, which was conducted between January 17 and February 16, 2024, tested the impact of financial incentives and reminder messages on flu vaccination uptake, focusing on patients who remained unvaccinated late in the flu season and despite multiple prior outreach attempts by the health system. A total of 69,972 adult patients overdue for influenza vaccinations were randomized to one of three arms: (1) standard care, (2) a reminder message, or (3) a reminder with a $50 financial incentive to get vaccinated within one week. We hypothesized that a reminder message with a financial incentive would increase vaccination uptake more than standard of care. We further hypothesized it would increase uptake more than a reminder message alone. We found that while reminder messages alone had no impact on vaccination uptake, the addition of a $50 incentive nearly doubled the 1-week vaccination rate-from 0.343% to 0.613% (a 0.27 percentage point increase; p < 0.001). Thirty days later the reminder message still had no impact relative to standard of care (0.14 percentage points, p-value 0.218) but the financial incentive effect persisted, increasing the vaccination rate from 1.55 to 1.92 percentage points (0.37 percentage points p-value 0.002). These findings suggest that financial incentives remain a powerful tool for increasing influenza vaccine uptake, even among those who remain unvaccinated late in the flu season. Trial Registration: NCT06300242.

Keywords: Financial incentive; Influenza vaccination; Reminder message.

 
Back
Top Bottom