Adapted from the Study Medication Satisfaction Questionnaire (Romaine et al 2019) designed and developed for trials of antivirals under evaluation for the prevention of HIV, the COVID-19 Treatment Satisfaction Questionnaire has been adapted to be suitable for COVID-19 vaccination trials. An open-ended question is included to check whether all items needed are included. All items have previously been tested with other patient groups and the format is that used in all our treatment satisfaction questionnaires.