After previously resisting calls to issue a statewide order for people to stay home to contain the spread of the coronavirus, Georgia Gov. Brian Kemp announced he was issuing such a directive and that it would take effect Friday.

Though Kemp's tightening of restrictions was welcomed by health officials, he drew criticism for his explanation that he was taking the step because the Centers for Disease Control and Prevention was now "finding out that this virus is now transmitting before people see signs."

"The CDC has announced that individuals can be infected and begin to spread coronavirus earlier than previously thought, even if they have no symptoms," Kemp said at a news conference Wednesday. He called the information "a revelation and a game changer."

The first-term Republican said that based on earlier CDC directives, his office had previously only been advising those who did not feel well to stay home.

"Those individuals could have been infecting people before they ever felt bad," Kemp said. "We didn't know that until the last 24 hours."

Kemp's press secretary told USA TODAY the governor was referring to a March 30 update from the CDC that said several studies show evidence of infected people who never showed symptoms. Because people who don't appear sick are not usually tested, "the prevalence of asymptomatic infection and detection of pre-symptomatic infection is not well understood," the CDC said.

The governor's office also referred to comments from CDC director Robert Redfield, who told NPR on Monday that the new coronavirus was "three times as infectious as flu," largely because as many as 25% of those infected never show symptoms and for those that do, they may not appear for up to 48 hours.

While Redfield's comments reflect a new understanding of the level of asymptomatic transmission, he and other health officials have warned that people who do not appear sick could be spreading the disease since late January.

At a Jan. 31 White House news briefing, National Institute of Allergy and Infectious Diseases Director Anthony Fauci said "in the beginning, we were not sure if there were asymptomatic infection, which would make it a much broader outbreak than what we’re seeing. Now we know for sure that there are."

Though the study Fauci based that comment on was later determined to be flawed by public health officials because the patient was found to have had mild symptoms, a Feb. 19 study – which the CDC cites in its update – appeared to confirm asymptomatic spread.

"I don’t think there’s any question that someone who is without symptoms and carrying the virus can transmit the virus to somebody else," Fauci told The New York Times later that month.

On Feb. 13, Redfield told CNN's Dr. Sanjay Gupta that he had discovered "the spectrum of this illness is much broader than was originally presented. There's much more asymptomatic illness." He said they were talking with medical professionals in China to determine "how much of the asymptomatic cases are driving transmission."

And on March 14, Deborah Birx, the White House coronavirus response coordinator, said, "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."

Democrats seized on Kemp's remarks that he was just learning the illness could be spread by people not displaying symptoms.

"If they had better election laws Stacey Abrams would be governor of Georgia. Brian Kemp’s negligence could cost Americans thousands of lives," tweeted Sen. Amy Klobuchar, D-Minn., who was a presidential candidate into early March.

"Kemp’s admission reveals that he and his administration hadn’t been listening to the health officials, including members of the White House coronavirus task force, who have been sharing that information for months," the Democratic Party of Georgia said in a statement. "Health officials knew. Americans knew. Brian Kemp failed to act, and now Georgians are paying the price."

"This is why we need a national test, trace, and quarantine program," tweeted Sen. Chris Murphy, D-Conn. "Because Governors and Mayors aren't public health experts, and Kemp isn't alone in totally misunderstanding the science and making fatal mistakes as a consequence."