Aim: This study examined the influence of pandemic fatigue on clinical nurses' mental health, sleep quality and job contentment, with resilience as a mediator.

Background: Pandemic fatigue is an emerging health concern among frontline clinical nurses as a consequence of the ongoing coronavirus pandemic and the various measures implemented to slow the spread of infection. As yet, no studies have investigated the link between pandemic fatigue and resilience, mental health, sleep quality and job contentment in frontline clinical nurses.

Methods: This was a descriptive, cross-sectional study involving 255 frontline clinical nurses in the Philippines. The Pandemic Fatigue Questionnaire, Brief Resilience Scale, Job Contentment Scale and the Sleep Quality Scale were used to collect data through an online survey.

Results: The mean pandemic fatigue score was 3.086 (out of 5). Being vaccinated (β = 0.231, p < .001) and increased staffing levels (β = -0.488, p < .01) were associated with decreased pandemic fatigue in clinical nurses. Resilience partially mediated the relationships between (a) pandemic fatigue and mental health (β = -0.488, p < .001), (b) pandemic fatigue and sleep quality (β = -0.326, p < .001) and (c) pandemic fatigue and job contentment (β = -0.395, p < .001).

Conclusion: Clinical nurses who received a COVID-19 vaccine and those who perceived sufficient staffing in their units reported lower levels of pandemic fatigue. Resilience reduces the effects of pandemic fatigue on clinical nurses' mental health, sleep quality and job contentment.

Implications for nursing management: By providing frontline nurses with access to COVID-19 vaccines and ensuring sufficient staffing levels, nurse managers could effectively reduce or prevent pandemic fatigue and improve their mental health. Implementing resilience-promoting measures are essential to support nurses' mental health, promote their sleep quality and foster job satisfaction.