Table A3.

Key questions and items in the survey questionnaire (translated from the Chinese version used).

Construct	Question No. and type	Items	Response Scale
Perception for financing mechanism	37 [Single Choice]	Do you think that individuals need to pay out of pocket for COVID-19 vaccination?	1 = No 2 = Yes, pay for a portion 3 = Yes, pay fully
	40 [Single Choice]	Do you think that governments need to pay for COVID-19 vaccination?	1 = No 2 = Yes, pay for a portion 3 = Yes, pay fully
	41 [Single Choice]	Do you think that health insurance needs to pay for COVID-19 vaccination?	1 = No 2 = Yes, pay for a portion 3 = Yes, pay fully
The out of pocket WTP	38 [Open-ended]	If individuals are required to pay for COVID-19 vaccination to complete a full immunization, what is the self-paid proportion that you are willing to pay?	[Range:0–100%]
	39 [Single Choice]	What is the maximum amount that you are willing to pay for COVID-19 vaccination (receiving all doses of the series as the vaccination schedule), if you want to get vaccinated?	1 = Refused vaccination 2 = Willing to get vaccinated if free 3 = CNY 10 4 = CNY 50 5 = CNY 100 6 = CNY 200 7 = CNY 500 8 = Willing to pay for any price
	50 [Open-ended]	What is the maximum amount that you are willing to pay for COVID-19 vaccination (receiving all doses of the series as the vaccination schedule), if you want to get vaccinated?	[For respondents who choose 'Refused vaccination' in Q39, skip Q50]

Note: […] Brackets indicate text that participants did not see, including question type and response options.