The study, released Friday, was based on COVID-19 data maintained by Johns Hopkins University and evaluated the impact of 18 rallies that took place between June 20 and September 30 of this year.
The study was not based on individual COVID-19 infections that were traced back to Trump rallies. Instead, the researchers compared the spread of SARS-CoV-2, the virus that causes COVID-19, in areas surrounding the locations of the rallies to its spread in similar locations throughout the US that did not host rallies.
Through their analysis, the researchers concluded that thousands of people may have become infected with the novel coronavirus by attending Trump’s rallies.
“Our analysis strongly supports the warnings and recommendations of public health officials concerning the risk of COVID-19 transmission at large group gatherings, particularly when the degree of compliance with guidelines concerning the use of masks and social distancing is low,” the researchers wrote.
“The communities in which Trump rallies took place paid a high price in terms of disease and death.”
B. Douglas Bernheim, a study author who also serves as the chair of Stanford's Economics Department, told Politico that the purpose of the study is to help policymakers understand the relation between large public gatherings and COVID-19 infections.
"There's currently this very important debate going on about the costs and benefits of lockdowns, restrictions and so forth," Bernheim told the outlet. "It's important that debate be informed by good information."
However, the White House has called the study “flawed.”
"As the president has said, the cure cannot be worse than the disease, and this country should be open armed with best practices and freedom of choice to limit the spread of COVID-19," White House spokesperson Judd Deere said in a statement obtained by Politico.
Trump campaign spokesperson Courtney Parella also said that supporters at rallies have their temperature checked, are given masks and are provided with hand sanitizer.
“Americans have the right to gather under the First Amendment to hear from the president of the United States, and we take strong precautions for our campaign events,” Parella said.
Michael Mina, an epidemiologist at the Harvard T.H. Chan School of Public Health, has warned against drawing strong conclusions from the study.
“There are better ways to look at this data through actual infectious disease epidemic lenses. It offers a data point, but nothing I would want to draw any strong conclusions from. It is also so overtly political that it makes it hard to distinguish if there were decisions made out of perhaps unrecognized bias,” Mina told Politico.
However, Eleanor Murray, an assistant professor of epidemiology at the Boston University School of Public Health, said the study “applies an appropriate method with some good robustness and sensitivity checks.”
“If the key underlying assumption is realistic, then the answer is probably something that could be relied upon,” Murray said.
The latest data by Johns Hopkins shows that there have been more than 9.2 million documented cases of COVID-19 in the US and more than 231,000 deaths as a result.