Message Testing in India for COVID-19 Vaccine Uptake: What Appeal and What Messenger Are Most Persuasive?

"Effective strategies to encourage COVID-19 vaccination uptake must consider how different aspects of health communication can be tailored to specific contexts."

Vaccine hesitancy - the reluctance or refusal to vaccinate despite availability of vaccines - has impacted efforts to control the SARS-CoV-2 (COVID-19) pandemic in many populations, including India. Evidence indicates that health communication vaccine messaging can affect attitudes and subsequent behaviours. This study evaluates the influence of three specific messaging appeal framings - COVID-19 disease health outcomes, social norms related to vaccination, and economic impact of COVID-19 - from two kinds of messengers, healthcare providers (HCPs) and peers, on COVID-19 vaccine acceptance in India.

The researchers surveyed 534 online participants in India from December 2021 through January 2022. Each participant viewed six ads featuring a HCP image, which depicts a medical provider talking to a patient, and a peer image, which depicts two people speaking to each other. The ads included the following appeals: health outcome, which focused on the risk of COVID-19 disease and the protective effect of vaccination against disease; social norms, which focused on how most people have received the COVID-19 vaccine and the protective effect of vaccination for the community; and economic benefit, which focused on loss of work time and income due to COVID-19 infection and the protective effect of vaccination against economic loss. After each ad, the researchers asked participants a series of questions and used multivariable multinomial logistic regression to examine ad preference and vaccine hesitancy.

Nearly all participants (n = 511, 96.2%) reported being vaccinated against COVID-19. More than a quarter (n = 145, 27.7%) reported having ever delayed or refused a recommended vaccination. Most participants were at least slightly concerned that the vaccine might not prevent COVID-19 disease (n = 430, 80.5%) or might not be safe (n = 378, 70.8%). Few participants had a score of 0 on the vaccine hesitancy scale (n = 73, 13.7%). (The image above shows participant ranking of concerns about the vaccine.)

Participants expressed a high level of approval for all of the ads, with more than 80% positive responses for all questions across ads. Overall, participants preferred ads delivered by HCPs (n = 381, 71.4%). Ad preference ranged from 3.6% (n = 19) social norm/peer ad to 32.4% (n = 173) health outcome/HCP ad, and half of participants preferred the health outcome ad (n = 279, 52.3%). Vaccine hesitancy was not related to preference (p = .513) for the six ads, or to HCP vs. peer ads (p = .522), or to message type (p = .284).

Reflecting on the findings about the messenger (preference for the HCP messenger), the researchers note that, despite the broad erosion of trust in healthcare systems in some settings during the pandemic, studies show that HCPs remain a critical trusted source of health information, including vaccine information. However, the pandemic has also highlighted the importance of peer influence, given the ubiquitous nature of peer-to-peer information exchange on social media platforms, and, as such, nurturing peer ambassador approaches could be another avenue to increase vaccine acceptance.

In terms of the preference for the health outcome ad, studies have shown that appeals focused on health outcomes have increased the salience of a disease threat in some contexts. However, social norms and attitudes also act as strong determinants of vaccine intentions and behaviours, and several studies have demonstrated the importance of social norms in affecting COVID-19 attitudes and intentions. In times of uncertainty such as the pandemic, individuals heavily rely on peer influence to inform their own decision-making. There is also evidence prior to the pandemic that the influence of social norms such as the higher perceived levels of approval of vaccination from close family and friends can be a strong predictor of intentions for other vaccines. These considerations may explain why the social norms frame was preferred more than the economic frame.

In conclusion: "Given the substantial morbidity and mortality that COVID-19 has exacted upon India specifically and the world generally, it will be...crucial to ensure that vaccine messaging is persuasive, salient, and induces action."