Vaccination under pessimistic expectations in clinical trials and immunization campaigns

Area of Science:

• Decision theory
• Behavioral economics
• Public health

Background:

• Vaccination campaigns are critical for disease control.
• Individual decision-making under uncertainty impacts public health interventions.
• Ambiguity aversion, a preference for known risks over unknown ones, can influence health behaviors.

Purpose of the Study:

• To formalize vaccination campaigns within a decision-theoretic framework.
• To analyze how ambiguity aversion affects individual prevention efforts and vaccine efficacy estimation.
• To explore the implications for clinical trials and large-scale immunization programs.

Main Methods:

• Developed a decision-theoretic model of individual prevention effort.
• Incorporated ambiguity aversion into the model.
• Analyzed the impact of individual behavior on vaccine efficacy estimation in trials and campaigns.

Main Results:

• Ambiguity aversion significantly affects individuals' prevention efforts and their participation in clinical trials.
• Optimistic individuals are more likely to join trials, altering their behavior and effort levels.
• Observed behaviors and efforts complicate the accurate evaluation of biological vaccine efficacy.
• Vaccine hesitancy can be a rational response during the scale-up phase of vaccination, even if efficacy is established.

Conclusions:

• Individual ambiguity aversion poses challenges for accurately assessing vaccine efficacy.
• Behavioral factors, driven by ambiguity aversion, can lead to rational vaccine hesitancy.
• Understanding these decision-theoretic aspects is crucial for effective public health policy and vaccination strategies.