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Brian Kemp, the Republican governor of Georgia, admitted on Wednesday that he had only just learned that asymptomatic individuals can still spread coronavirus — even though health experts had warned about the possibility as early as January.

Kemp, in a news conference Wednesday said the fact that he’d just learned that information contributed to him issuing a statewide shelter-in-place order.

Kemp, said that he had, in just the last 24 hours, learned “that this virus is now transmitting before people see signs.”

“So what we’ve been telling people from directives from the CDC for weeks now, that if you start feeling bad stay home, those individuals could have been infecting people before they ever felt bad,” Kemp said.

“Well, we didn’t know that until the last 24 hours” he added. “This is a game-changer for us,” Kemp said.

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On Monday, Centers for Disease Control and Prevention Director Dr. Robert Redfield told NPR station WABE of Atlanta that as many as 25 percent of infected people remain asymptomatic, and that people without symptoms do contribute to the transmission of the virus.

On Thursday, Georgia's health department in a statement said that it had been known for weeks that infected people without symptoms were likely able to spread it, but it referred to Redfield's comments and characterized it as new data.

"Additionally, science also now informs us that individuals who are symptomatic, are infectious up to 48 hours before symptoms appear," the state Department of Public Health said. "This new information tells the health care community, medical researchers, public health and governments why COVID-19 is spreading so rapidly."

The CDC said as early as March 30 that coronavirus could be spread by asymptomatic individuals who had been infected. However, prominent doctors had publicly discussed that finding for months.

"There's no doubt ... that asymptomatic transmission is occurring," Dr. Anthony Fauci, director of the National Institute for Allergy and Infectious Diseases, said in January, though it was unclear at the time how the widespread it was occurring.

Dr. Deborah Birx, the coronavirus response coordinator for the White House Coronavirus Task Force, said last month that young people in particular could be spreading the virus without knowing.

"Until you really understand how many people are asymptomatic and asymptomatically passing the virus on, we think it's better for the entire American public to know that the risk of serious illness may be low, but they could be potentially spreading the virus to others," Birx said.

Kemp said it was learning that information that led him to issue his shelter-in-place order, making him just the latest U.S. governor to do so. The order will go into effect Friday and will last through at least April 13.

He also said that Georgia would need additional time to help prepare its hospitals for the expected surge of infected patients.

As of Thursday evening Georgia had 5,444 confirmed cases of coronavirus and 176 deaths, according to the state’s department of public health.