- "We really don't have evidence that children are driving the transmission cycle of this," Redfield said at a White House Task Force briefing to address school reopenings.
- But there's not enough data to definitely arrive at that conclusion, White House health advisor Dr. Deborah Birx said later in the briefing on Wednesday.
- "Our data is skewed originally to people with symptoms, and then skewed to adults over 18, so we are looking very closely into that category by using our antibody test," Birx said.
The director of the Centers for Disease Control and Prevention, Dr. Robert Redfield, said Wednesday there's no evidence that children drive the spread of the coronavirus. But that's likely because the U.S. hasn't tested enough kids to know one way or the other.
"We really don't have evidence that children are driving the transmission cycle of this," Redfield said at a White House Task Force briefing to address school reopenings.
It's a point that was also cited at a White House event Tuesday on school reopenings by American Academy of Pediatrics President Sally Goza, who said, "Children are less likely to become infected and they are less likely to spread infection."
But there's not enough data to arrive at that conclusion, White House health advisor Dr. Deborah Birx said later in the briefing on Wednesday. She said U.S. data is incomplete, because the country has not been testing enough children to conclude how widespread the virus is among people younger than 18 and whether they are spreading the virus to others.
The question of whether kids might be a driver of transmission is key, especially as local officials decide whether and how to reopen schools in the fall. President Donald Trump has been mounting pressure on officials to reopen schools for in-person learning in the fall even as the country grapples with the largest outbreak in the world. And while kids appear to be less likely to get severely sick from Covid-19, their role in the broader spread of the virus is unknown.
"I think it really comes to the evidence base of what do we have as far as testing in children," Birx said Wednesday, addressing a question about whether kids spread the virus. "So if you look across all of the tests that we've done, and when we have the age, the portion that has been the lowest tested portion is the under-10-year-olds."
Testing resources have been tight in the U.S. since the first Covid-19 patient in the U.S. was identified in late January. As a result, severely sick people and those who have symptoms have been prioritized to be tested. CDC data indicates that younger and otherwise healthy people are less likely to become sick or develop Covid-19 symptoms, so the U.S. hasn't tested many of them, Birx said.
"Remember, early on, we said test if you have symptoms and now we know that if you're under 18, the majority of you don't have symptoms," Birx said, explaining the lack of data on children in the U.S. "Our data is skewed originally to people with symptoms, and then skewed to adults over 18, so we are looking very closely into that category by using our antibody test."
Antibody tests are used to determine whether someone has previously been infected with the coronavirus. Large-scale antibody tests are used to determine how prevalent the virus has circulated throughout a given community. They have been used by scientists to study how many people, both with and without symptoms, have been infected with the virus in hard-hit cities like New York.
Representatives from the Centers for Disease Control and Prevention were not immediately available to answer CNBC's inquiry on whether the agency is conducting a widespread antibody survey among minors.
While proponents of aggressively reopening schools say the coronavirus does not present a major health risk to most kids, others worry that kids in packed school buildings could become infected and spread the virus to parents, who may be more susceptible to severe illness.
White House health advisor Dr. Anthony Fauci, who was not present at Wednesday's briefing, has previously said that even though children don't appear to be as vulnerable as older people, kids can still become extremely sick and even die from Covid-19.
"Even though the incidence is less of serious complications, we are now getting multiple examples of young people who are getting sick, getting hospitalized and some of them even requiring intensive care. The death rate is lower. I admit that," Fauci said during a livestreamed event with Democratic Sen. Doug Jones of Alabama.
"Even if you do not get any symptoms and you do perfectly well, by getting infected, by allowing yourself to get infected because of risky behavior, you are part of the propagation of the outbreak, so you are part of the problem," he added.
The inconclusive remarks come as the Trump administration ramps up pressure on local officials to reopen schools even as the U.S. continues to report record-breaking spikes in daily new cases.
Earlier Wednesday, Trump tweeted that he disagrees with the CDC's guidelines on reopening schools safely in the fall, calling them tough and expensive. Vice President Mike Pence said at the briefing Wednesday the agency will release revised guidelines in the coming weeks.
The CDC published guidelines in May for what schools ought to consider in how to bring students back into buildings. The guidance recommends more frequent and intensive cleanings, distancing students, closing communal areas and more. That could mean asking schools to hire more staff and invest in re-fitting school buildings, which could weigh especially heavily on districts with less funding.
Trump's tweet about the guidelines comes one day after he vowed to pressure state officials and educators into reopening schools — even as several states continue to grapple with rapidly expanding outbreaks.
"We're very much going to put pressure on the governors and the schools to reopen," Trump said at a White House event Tuesday on school reopenings. "Open your schools in the fall," the president told state officials and school teachers in attendance.
Schools across the country closed early for the year when the virus hit the U.S. hard in March, moving from in-person learning to distance, or virtual, learning. However, educators have emphasized that virtual learning is disruptive to student growth and many students depend on their schools as a safe environment and source of meals.