1. Inclusion criteria .

Criteria	Details
Study designs	RCTs  Observational studies (case‐control, cohort, cross‐sectional)  Prospective and retrospective design Controlled pre‐post studies  Interrupted time‐series studies  Non‐comparative/non‐controlled: Single‐arm studies with more than 100 participants Case studies with 100 or more participants Rapid/living/scoping/systematic reviews/ meta‐analyses Psychological experiments
Population	Any population, no restrictions
Setting	No restrictions
Interventions	Interventions to enhance the willingness to get vaccinated with a COVID‐19 vaccine Intervention to decrease vaccine hesitancy for a COVID‐19 vaccine
Outcomes	No restrictions

RCTs: randomised controlled trials