This study is a PhD project conducted by Ms. Hina Hakim, supervised by Dr. Holly O. Witteman, PhD, and co-supervised Dr. Daniel Reinharz, professors and researchers at the Faculty of Medicine at Laval University. The purpose of this study is to evaluate the effects of visualization conveying the concept of community immunity or herd immunity on risk perception (towards individual, family, community and vulnerable people in communities) (primary outcome) and on emotions, attitudes, knowledge, and behavioural intentions (secondary outcomes).

Visualization is a powerful communication mechanism that uses pre-attentive processing to communicate large amounts of information rapidly in understandable and compelling ways (Healey and Enns 2012). A systematic review demonstrates that there are some interventions available for conveying the concept of community immunity, and very few evaluate interventions for their effects on vaccine intentions and uptake as well as their precursors, such as knowledge, attitudes, knowledge and none on emotions (Hakim et al. 2018).

The purpose of this study is to evaluate the effects of visualization conveying the concept of community immunity on risk perception (to individual, family, community and vulnerable people in communities) (primary outcome) and on emotions, attitudes, knowledge, and behavioural intentions (secondary outcomes).

Inclusion Criteria:

• Members of the general population in Canada
• At least 18 years old
• Able to provide free and informed consent
• Able to read and understand French or English
• Able to use a computer

Exclusion Criteria:

- No internet access

Anonymized data (answers to questions in the survey including socio-demographic information) will be deposited in a public repository (Dataverse de l'Université Laval (Laval University)) which will allow data sharing with the scientific community. No information that would allow anyone to identify a person will be deposited in this public repository. Study protocol and statistical analysis plan have been deposited in Open Science Framework.

As soon as possible upon completion of the study and posting of a preprint with results.

Freely available.

This will be a single-blinded study because we cannot mask participants to the fact that they have been randomized to a visualization e.g., about measles. However, participants will not necessarily know the purpose of the study arm to which they are assigned,and investigators will be blinded to study arm during data analysis (investigators are not aware of whether the next eligible participant will be receiving treatment or control intervention.)