Researchers have been warning since at least February, if not earlier, that people infected with the novel coronavirus could spread the illness to others even if they weren’t showing symptoms; but Georgia Gov. Brian Kemp says he only learned of this phenomenon in the “last 24 hours.”

Georgia had been one of the minority of states that had lacked a statewide shelter-in-place mandate, but Kemp ― who’d repeatedly resisted implementing such widespread restrictions ― on Wednesday said he was escalating the state’s fight against the coronavirus, known as COVID-19.

At a press conference, the Republican governor announced a statewide order calling all residents to shelter in place for two weeks, as well as the closure of all schools for the remainder of the academic year.

Explaining his rationale for the enhanced restrictions, Kemp said he’d just learned that asymptomatic coronavirus patients can spread the illness.

“I’m following the data,” the governor said. “Finding out that this virus is now transmitting before people see signs ... what we’ve been telling people from directives from the [Centers for Disease Control and Prevention] for weeks now that if you start feeling bad, stay home ― [but] those individuals could have been infecting people before they ever felt bad, but we didn’t know that until the last 24 hours.”

CDC Director Robert Redfield said Monday that as many as 25% of people infected with the new coronavirus could show no symptoms. He noted that it was only in recent weeks that the CDC had been “pretty much” able to confirm that asymptomatic transmission of the virus was happening.

Still, Redfield has been sounding the warning bell since mid-February that asymptomatic patients could spread the disease.

“There’s been good communication with our colleagues to confirm asymptomatic infection, to confirm asymptomatic transmission,” he told CNN at the time.

A stunning admission of deadly ignorance from Georgia Gov. Brian Kemp, who says he only just learned that asymptomatic people can transmit #Covid19. “[I]ndividuals could have been infecting people before they ever felt bad, but we didn’t know that until the last 24 hours.” pic.twitter.com/T7NZWk2GDR — Andisheh Nouraee (@andishehnouraee) April 2, 2020

Researchers have been warning since at least January that there was evidence that people with no or mild symptoms could still spread COVID-19. U.S. researchers asserted last month that asymptomatic transmission of COVID-19 appeared to be a “major driver” of the global pandemic.

Still, there remains a lot that is unknown about asymptomatic coronavirus patients, including how many infected people show no symptoms, how long they are contagious and just how big a role they’ve played in the spread of the disease.

More than 4,700 people in Georgia have been diagnosed with COVID-19 since early March, according to a New York Times tally. At least 154 people in the state have died from the virus.