Only 20% of people who get COVID-19 show no symptoms of the disease — a much lower estimate than previously thought. Dr. Anthony Fauci stated in July that “20% to 40% are essentially asymptomatic,” but new research that analyzed 94 previous studies on the coronavirus and its symptoms, concluded that the actual number of people who show no symptoms is only one in five.

According to Newsweek, another interesting finding of the study was that individuals who were asymptomatic were less likely to transmit the disease to others. Nicola Law, an epidemiologist at the University of Bern in Switzerland and a co-author of the study, told Newsweek that the review found a minority of people are “truly asymptomatic” and “probably account for a relatively small amount of all SARS-CoV-2 transmission.”

She added that since most people develop symptoms, it is important to always follow proper precautions to prevent transmission by such actions as social distancing, wearing masks and continuing to test and trace.

Many experts have already criticized the new data, mainly because it relied too heavily on studies from China where overall surveillance of symptoms differed from other countries. Researcher Daniel Oran also co-authored a study on the prevalence of asymptomatic SARS-CoV-2 infection, and his research found that 32% of cases in England and 33% in Spain were asymptomatic.

Julian Tang, a virologist at the University of Leicester, said the study did not screen for other respiratory viruses that may have caused symptoms and that most of the source material used focused on hospitalized patients.

“Clearly such patients are more likely to have symptoms as this is why they attended hospital,” he said, according to Newsweek, adding that he would approach the findings “with some caution, and use their estimate of a 20% asymptomatic infection rate as just a lower limit.”