White House coronavirus response coordinator Dr. Deborah Birx expressed concern during a visit to Chicago Tuesday about the growing number of counties in Illinois where 5% to 10% of COVID-19 tests are coming back positive.

“Over the last four weeks we’ve seen a steady increase in the number of counties that are over 10% and over 5% test positivity,” Birx said at a press conference following a private meeting with state and local officials at Rush University Medical Center.

Illinois now has more than 60 counties where 5% or more of tests are coming back positive, and more than a dozen of those counties have test positivity rates of 10% or higher, according to the Illinois Department of Public Health.

She said “intensifying communication” with rural areas could help turn those numbers around, citing Ohio as an example.

“When we see those rural counties move into the 5% range and continue to increase, it’s really an alert to every rural community that you need to take the same precautions as the urban communities are taking,” Birx said.

“Ohio has been able to reverse community spread in rural areas by using mask mandates, increasing awareness of social distancing and really making sure people understand that even in a family gathering, you have to still do these social distancing elements to protect one another,” she said.

When asked whether Illinois did the right thing by instituting a stay-at-home order early on and conducting a phased re-opening, Birx said Southern states have proved that the illness can be curbed with other types of mitigation measures, such as limiting activity in bars, reducing indoor dining and wearing masks.

Pritzker and many state health officials have credited the March 21 stay-at-home order with slowing the growth of COVID-19 in Illinois earlier this year, and have said it helped prevent most area hospitals from becoming overwhelmed at the height of the illness here. Pritzker had decried the lack of a national stay-at-home order early in the pandemic.

“The model we have followed here in Illinois is one in which science and public health guide our decisions, and that has led us to Illinois having the lowest positivity rate compared to our neighboring states and saved thousands of lives,” said Jordan Abudayyeh, a spokeswoman for Pritzker, in a statement Tuesday responding to Birx’s comments.

The U.S. has had more cases of the illness than any other country, according to the World Health Organization. As of Tuesday, 8,064 people had died of the illness in Illinois.

Birx visited Illinois Tuesday as part of a states tour in which she’s been emphasizing the importance of wearing masks and social distancing even from family members. She said it’s an especially important message with Labor Day approaching.

“We’re seeing that the majority of community spread now is happening at the neighborhood and family gathering level,” she said.

She was scheduled to meet with Gov. J.B. Pritzker Tuesday.

Birx addressed recent controversial comments made by Food and Drug Administration Stephen Hahn over when the FDA might approve a potential vaccine. The Financial Times reported Sunday that Hahn said the FDA was prepared to authorize a vaccine before phase three clinical trials were complete, if the benefits outweighed the risks. He said he would not rush a vaccine to please the president.

Health experts have expressed concerns about rushing out a vaccine before it’s fully tested.

Birx said Tuesday she believes the commissioner was trying to say a vaccine could gain emergency use authorization before phase three trials are complete if it proves effective and helps people develop protective immune responses.

“There’s a lot that goes into that, and I think that’s what he was trying to communicate, but it’s very clear that the FDA is not going to authorize use without definitive efficacy,” Birx said.