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If the COVID-19 pandemic could be boiled down to one lesson, it is the fact that vaccines played an effective role in limiting the spread of infectious disease. Sure, supply chain issues that impact manufacturing and distribution efforts can occur—alongside length regulatory approval processes—but no process is flawless.
Interestingly enough, out of the 11 COVID vaccines that the World Health Organization (WHO) recommended for public use, only six of those originated from the United States. That means that five of them came from foreign countries.
This raises the question: how much of an impact does public hesitancy have in receiving foreign vaccines? Can it ultimately incentivize governments to avoid acquiring certain ones? A study published in Social Science & Medicine1 sought to explore exactly that, specifically by digging into public support during a pandemic’s early stages and whether WHO can alleviate potential biases.
The study investigators used a randomized controlled trial that was embedded in a public opinion survey to evaluate the impact of vaccines’ countries of origin on vaccination policy preferences. This was accomplished by providing respondents with a hypothetical influenza pandemic scenario, followed by asking them to deliberate various hypothetical first-available vaccines that presented differing clinical features, whether that be antigen type, country of origin, efficacy in preventing severe illness, and if the WHO endorsed each vaccine.
The United States was selected as the location of the study, and in September 2023, 1,110 residents were to rate their support the vaccine purchasing policies of 20 hypothetical evaluations and a total of 13,320 evaluations. Participants were stratified by age (18-24, 25-34, 35-50, 51-60, 61-100), whether they have not taken any COVID vaccine, and the political party they identified with (Republican, Democrat, Other/Don’t Know).
After examining various linear regression models, the investigators noticed that compared to the foreign vaccines from countries that Americans see as favorable—such as the United Kingdom and Germany—those coming from “less favorable” countries (China, Russia), received less support for government to acquire those specific vaccines. In fact, following a causal mediation analysis, this type of country-of-origin effect stems from participants’ feelings toward the vaccine. Having a WHO endorsement hardly had an impact on diminishing the effect of the vaccine’s country of origin.
Following this analysis, the study authors concluded that, “ … we presented novel experimental evidence of vaccine purchasing policy favoritism toward initial vaccines produced in countries that Americans deem to be favorable instead of unfavorable. We further offer a mechanism by which this bias occurs, by documenting that the negative affect toward vaccines produced in unfavorable countries mediates the effects of the country-of-origin on policy preferences.
“In addition to the large substantive magnitude of these effects, we find that—although we might expect endorsement from widely respected global health agencies that represent public health interests across a diverse range of national contexts, like the WHO, to mitigate country-of-origin effects—preferences for vaccines produced in countries deemed favorable persist irrespective of WHO endorsement. Both country-of-origin effects, and the failure of WHO endorsements to combat them, persist irrespective of objective vaccine quality as rated by medical professionals, as well as individual-level vaccine skepticism and vulnerability to severe infection.”
These findings were consistent across various sample subsets, even after keeping vaccine quality in mind.
Reference
1. Heinrich T, Kobayashi Y, Motta M. Which foreign vaccine should the government purchase in a pandemic? Evidence from a survey experiment in the United States. Soc Sci Med. 2024 Apr;347:116766. doi: 10.1016/j.socscimed.2024.116766. Epub 2024 Mar 13. PMID: 38502981.
