Willingness to get a COVID-19 vaccine was considerably higher in developing countries (80% of respondents) than in the United States (65%) and Russia (30%), according to new research published July 16 in Nature Medicine.

The study provides one of the first insights into vaccine acceptance and hesitancy in a broad selection of low- and middle-income countries, covering more than 20,000 survey respondents and bringing together researchers from more than 30 institutions, including Cornell, the International Growth Centre, Innovations for Poverty Action, WZB Berlin Social Science Center, the Yale Institute for Global Health, the Yale Research Initiative on Innovation and Scale, and HSE University in Moscow. 

Personal protection against COVID-19 was the main reason given for vaccine acceptance among respondents in low- and middle-income countries (91%), and concern about side effects (44%) was the most common reason for vaccine hesitancy. Health workers are considered the most trusted sources of information about COVID-19 vaccines.

“Communication about the COVID-19 vaccine should continue to emphasize the mild and temporary nature of side effects rather than focusing on severe but outlier cases that our research has consistently found have an outsized impact on individual psychology about COVID-19 vaccination,” said study co-author Sarah Kreps, the John L. Wetherill Professor in the Department of Government and director of the Cornell Tech Policy Lab in the College of Arts and Sciences.

The study comes at a critical juncture when vaccine shipments are still slow to arrive to the majority of the world’s population, and COVID-19 cases are surging in many parts of Africa, Asia and Latin America. The findings suggest that prioritizing vaccine distribution to low- and middle-income countries should yield high returns in expanding global immunization coverage.

“This study highlights the importance of equitable access to COVID-19 vaccines worldwide,” said Baobao Zhang, Klarman postdoctoral fellow in A&S and study co-author. “Those living in the U.S., the population that my team studied, have access to multiple vaccines against COVID-19; at the same time, vaccine hesitancy in the U.S. is relatively high compared with other countries in our study. In contrast, there are many parts of the world where vaccine acceptance is high yet the public has very limited access to vaccines.”

Added Kreps: “Each of these countries represents both a potential outbreak and opportunity for the virus to mutate into more deadly variants that will invariably become global, which the Delta variant has shown to be the case.

“These findings suggest that the U.S. should continue to target the unvaccinated populations within its own country but work to increase access of its vaccines to these countries that want the vaccine, will benefit from the vaccine, and will ultimately impact the public health situation here at home,” Kreps said.

The researchers, who conducted the surveys between June 2020 and January 2021, point out that vaccine acceptance may vary with time and the information that people have available to them. While more evidence on the safety and efficacy of available COVID-19 vaccines has emerged in the last six months, severe, but rare, side effects may have undermined public confidence.

“As COVID-19 vaccine supplies trickle into developing countries, the next few months will be key for governments and international organizations to focus on designing and implementing effective vaccine uptake programs,” said Niccoló Meriggi, country economist for IGC Sierra Leone and study co-author. “Governments can use this evidence to develop communications campaigns and systems to ensure that those who intend to get a vaccine actually follow through.”

 Linda B. Glaser is news and media relations manager for the College of Arts and Sciences.