Determinants of COVID-19 Vaccine Acceptance in the US

"With many COVID-19 vaccines under development...and substantial vaccination levels needed to achieve herd immunity, we must clearly understand the hesitancy and acceptance of a COVID-19 vaccine to develop evidenced based interventions."

Immunisation programmes are only successful when there are high rates of acceptance and coverage. As misinformation about COVID-19 has spread across media outlets in the United States (US) and globally, health communicators are being called upon to reach all communities, especially the most vulnerable, with education about the safety of vaccines. The purpose of this study is to describe the US vaccine acceptance landscape, with the goals of predicting COVID-19 vaccine acceptance, identifying the most vulnerable populations, and providing information for public health officials and politicians to develop messaging for all Americans, especially racial and ethnic minority communities and others affected by health disparities.

Specifically, the researchers note that, since the beginning of the COVID-19 pandemic in the US, it has been clear that low-income people and communities of colour are at higher risk for infection and death from COVID-19. Historical oppression and current disparities in care are linked to a mistrust of the healthcare system among some Black Americans and may result in these differences in health outcomes. Furthermore, low-income communities are disproportionately impacted by COVID-19, and there is intersectionality between race, socioeconomic status (SES), and health outcomes.

In early May 2020, 672 participants completed a questionnaire on CloudResearch, which is an online survey platform that allows for representative surveying.

Of those surveyed, 450 (67%) said they would accept a COVID-19 vaccine if recommended to them. The vaccine acceptance differed by demographic characteristics - with the following people more likely to accept the vaccine if it were recommended for them: males (72%) compared to females, older adults (55 years and older: 78%) compared to younger adults, Asians (81%) compared to other racial and ethnic groups, and college and/or graduate degree holders (75%) compared to people with less than a college degree. The median risk perception score amongst those who would accept the vaccine was 6 (interquartile range (IQR): 6-8) compared to a median of 5 (IQR: 2-6) amongst those who would not accept the vaccine.

The study found notable demographic differences when comparing reported influenza vaccine uptake - something the US already struggles with, as less than half of the adult population were vaccinated in 2019 - to reported acceptance of the COVID-19 vaccine. For example, participants who did not complete high school had a very low influenza vaccine uptake (n = 1; 10%), but of that same group, 60% (n = 6) said they would accept the COVID-19 vaccine if it were available and recommended to them. In addition, Black Americans reported lower influenza vaccine uptake (n = 28; 42%) and lower COVID-19 vaccine acceptance (n = 27; 40%) than nearly all other racial groups.

There were also notable geographic differences in COVID-19 vaccine acceptance by US region, with Department of Health and Human Services (DHHS) regions 2 (New York) and 5 (Chicago, Illinois) reporting less than 50% COVID-19 vaccine acceptance.

When asked what they considered to be the most reliable sources of information on COVID-19, participants referenced healthcare professionals (n = 503; 75%) and health officials (n = 470, 70%). Comparatively, 144 participants (21%) referenced social media as a reliable source of COVID-19 information.

In short, while a majority of respondents (67%) from across the US would accept a COVID-19 vaccine, this level of acceptance may not be sufficient for the herd immunity threshold for SARS-CoV-2, the virus causing COVID-19, which is estimated to be between 55% and 82%. Also, the study shows that the very groups that are most susceptible to COVID-19 illness and death - e.g., communities of colour - are the ones that are least likely to intend to accept a COVID-19 vaccine. Thus, to counter misinformation and improve trust, thoughtful and targeted messaging needs to be developed and tested now - not only for the general US population but also specifically for high-risk groups. This emphasis "indicates a need for cultural humility and community engagement. Additionally, how these messages are made available to the public should be considered....Hence, health officials and healthcare professionals, including nurses and ancillary healthcare staff, should be engaged in community messaging to improve trust in a COVID-19 vaccine and increase uptake."

The researchers caution against assuming that reported acceptance or intent translates into actual behaviour. The 24-hour coverage on US news networks and online media of COVID-19 may make the pandemic more salient in daily life, especially when compared to influenza. In addition, during a pandemic and immediately around a new vaccine release, excitement about a vaccine is at its highest. The researchers report other limitations of the study as well. However, they conclude that this study has revealed "demographic and geographical variations in rates of acceptance that need to be carefully addressed. Policymakers and stakeholders should focus on evidence-based community messaging to improve uptake and break the transmission dynamics."