An Experimental Study on how Messaging from CDC Affects Attitudes toward Mandatory MMR Vaccination for Schoolchildren.

Background: During the COVID-19 pandemic, public health institutions, particularly the Centers for Disease Control and Prevention (CDC), were frequently attacked by politicians. Popular trust in these institutions declined, particularly among self-identified Republicans. Therefore, the effectiveness of public health institutions as vaccination messengers might have been weakened in the post-COVID-19 period. We conducted a survey experiment examining the effectiveness of messaging from the CDC in shaping people's attitudes toward mandatory MMR (measles-mumps-rubella) vaccination for schoolchildren.

Methods: The experiment was embedded in a survey fielded in South Dakota, a "red state" with a population predisposed to distrust the CDC. Using registration-sampling, we received 747 responses. We used difference-in-means tests and multivariate regression to analyze the data.

Results: We found that participants who received a message from the CDC were more likely to support MMR vaccine mandate for schoolchildren than participants who received the same prompt from a state agency. Further analyses showed that messaging from the CDC was particularly effective among Republicans.

Discussion: Overall, our study showed that although the CDC was caught up in the political skirmishes during the COVID-19 pandemic, it remains an authoritative source of public health information.

Conclusions: Public health officials at the local and state levels should not shy away from referring to the CDC in their vaccination messaging.