The Benefits and Limitations of Vaccine Advertising

Vaccine hesitancy continues to be a concern for the United States as we strive to reach herd immunity against COVID-19. However, these vaccines are not the only ones drawing speculation. Reaching adequate levels of vaccine coverage proves difficult for various reasons, such as barriers of awareness, availability, and hesitancy.

Although vaccines are one of the best public health interventions created, the United States has vaccinated only 35% of eligible adults against herpes zoster, 52% of females and 21% of males against human papillomavirus (HPV), and around 45% of adults annually against influenza.

Researchers from Boston College and Microsoft Research may have found a way to combat these low percentages. Participating search engines showed advertising campaigns in related web searches to approximately 69,000 individuals. The data collected through the search engines counted ad clicks and tracked any future searches concerning vaccines of interest.

Targeted ad campaigns revealed 2 primary effects on an individual’s behavior. The first effect discovered by the study is the congruence effect. When individuals who express initial interest in the disease or vaccine were shown a targeted advertisement, it increased the likelihood of ad clicks and future searches by up to 116%.

The second effect that advertisements revealed is the priming effect. This occurs when the targeted advertisement is displayed within a search that is unrelated to the disease or vaccine eligible to them. A significant portion of individuals who received an unrelated vaccine ad searched for vaccine information shortly after.

The researchers also discovered that increasing the number of sponsored advertisements appearing in web searches had a negative correlation with ad clicks. Advertisers should be cautious to not overwhelm individuals when designing public health campaigns.

­The findings presented in this study demonstrate the need to advertise vaccinations to a broader spectrum of individuals who do not necessarily look like existing customers. Doing so can draw in an untapped subset of the United States population. These individuals can and should be influenced by advertising to ultimately increase the number of people who vaccinate against preventable, communicable diseases.

Christopher Epps is a 2022 PharmD Candidate at the University of Connecticut in Storrs.

REFERENCE

Krupenkin M, Yom-Tov E, Rothschild D. Vaccine advertising: preach to the converted or to the unaware? Nature. 2021;2:23.