Resetting public adherence: iterative strategies to counteract pandemic fatigue.

Non-pharmaceutical interventions (NPIs) are essential for controlling infectious diseases during pre-vaccine periods, yet their success hinges on sustained public adherence. This study investigates adherence dynamics to tiered restriction systems implemented during COVID-19 in six geographical regions across Europe, North America, Africa, and South America. Using daily mobility data and linear-mixed models, we assessed three types of fatigue: overall fatigue (linked to cumulative time under restrictions), tier fatigue (linked to time spent under a specific tier), and iteration fatigue (linked to repeated implementation of the same tier). Tier fatigue caused the most rapid adherence loss, producing effects within days that overall fatigue required months of restrictions to achieve. Iterative application of shorter NPIs, interspersed with temporary relaxation, helped reset adherence, mitigating fatigue and sometimes even improving compliance. Psychological relief and a sense of regained autonomy during relaxation periods may renew public willingness to comply when restrictions are reintroduced. These findings emphasize the dual benefits of short, strategic NPIs for epidemic control and public resilience, offering actionable insights for designing more sustainable pandemic interventions.