This study will reveal how information provision to correct the misperception, “I have rubella antibodies,” affects the uptake of rubella antibody testing and vaccination.
To obtain herd immunity against rubella, Japan must increase the antibody prevalence rate for males born between 1962 and 1978 from 80% to 90%. To accomplish this, following request from the Ministry of Health, Labor, and Welfare (MHLW), local governments have mailed free vouchers for rubella antibody testing and vaccination to men of the target generation from FY2019 to FY2021. However, as of October 2021, the number of vaccination remained low at around 740,000 (about 39% of the target number of vaccination). Thus, the MHLW decides to re-distribute free vouchers also in FY2022. The vouchers will be mailed to males born between 1962 and 1978 who have not received an antibody testing during FY2019 to FY2021, or who have not been vaccinated even though they are the target generation of this policy.
Taking the results of our preliminary survey into account, we found that the subjects could form misperceptions, such as “I received the rubella vaccine when I was a child (even though there were no routine rubella vaccinations for their generations” or “I was infected with rubella in the past (even though they was actually infected with chickenpox or measles, nor rubella).” We focus on the possibility that these misperceptions may be a bottleneck of preventing them from getting tested and vaccinated. In this study, we create a flyer to correct these misconceptions and conduct a nationwide online experiment to evaluate its effectiveness.
We will conduct the online experiment in July-August 2022 (N=7,500), with two follow-ups in September 2022 and March 2023 to ascertain the impact of information provision on the behaviors of antibody testing and vaccination.
In July-August 2022, we will conduct one supplementary survey (A) to commplement the manupulation check in the main experiment (N=750). In addition, we will conduct another supplementary survey (B) to measure the demand for the information to correct the misperceptions (N=500).