Answer: Quantitative survey
Explanation:
Finding out the vaccination rates of people requires them to provide the researcher with a "yes" or "no" as to whether they have been vaccinated or not. It therefore does not require a complicated research method that would take time.
As such a quantitative survey would be best as the same set of questions can be printed and redistributed to people to find out their response on whether they have been vaccinated or not. Questionnaires would work best here.
