Reminders, but not monetary incentives, increase COVID-19 booster uptake

Area of Science:

• Public Health
• Epidemiology
• Behavioral Science

Background:

• Low COVID-19 booster vaccination rates persist globally, despite proven efficacy in reducing severe illness and mortality.
• Identifying effective strategies to increase booster uptake, especially in high-risk demographics, is crucial for public health.
• Previous interventions have shown mixed results in promoting vaccine adherence.

Purpose of the Study:

• To evaluate the effectiveness of personalized reminder messages and financial incentives in increasing COVID-19 booster vaccination rates.
• To determine the impact of these interventions on vaccination uptake within a large, diverse population.
• To provide evidence-based recommendations for public health campaigns aimed at improving booster vaccination coverage.

Main Methods:

• A large-scale, preregistered randomized controlled trial involving 57,893 participants was conducted within a northern California health system.
• Participants were randomized to receive either personalized reminder messages, a $25 financial incentive, or a combination of both, compared to a control group.
• Booster vaccination rates were assessed within a two-week period following the intervention.

Main Results:

• Personalized reminder messages significantly increased booster vaccination rates by 0.86 percentage points (P = 0.000), representing a nearly 33% increase over the control group's mean rate of 2.65%.
• Small financial incentives ($25) did not demonstrate any additional significant impact on booster vaccination rates when compared to reminders alone or the control group.
• The study highlights the efficacy of low-cost, targeted communication strategies in influencing health behaviors.

Conclusions:

• Personalized reminder messages are a cost-effective and impactful tool for increasing COVID-19 booster vaccination rates.
• Financial incentives of $25 were found to be ineffective in further enhancing booster uptake beyond the effect of reminders.
• Public health agencies can leverage targeted messaging strategies to improve vaccination coverage, particularly among populations at higher risk for severe COVID-19 outcomes.