5. Messages can take several forms; they can be one-sided, two-sided, or emotional. In health care, two-sided messages have been found to be highly effective as used in public health campaigns to inoculate them against weaker arguments before promoting the stronger argument for a positive behavior.

This approach is based on inoculation theory.
Because of the unique nature of health care, fear appeals may have some relevance with regard to population health management and public health campaigns.