The White House says in a statement on its website that it is hosting "members of our military, first responders, doctors, nurses, and other American heroes who fought the coronavirus pandemic on the front lines" at a White House Salute to America, part of its Fourth of July celebrations Saturday on the South Lawn.

It is not, however, immediately clear if the front line workers will be wearing masks and practicing social distancing, something President Donald Trump has been reluctant to do even though the U.S. is leading the world in COVID-19 infections. It has nearly 2.8 million of the world's more than 11 million infection cases.

The administration's public health officials have said mask wearing and social distancing can help halt the spread of the disease.

Several U.S. governors have reinstated the lockdowns they had begun to ease since a recent surge in cases swept across a number of states. The news of the reversals came just before the start of the Fourth of July holiday. Authorities are hoping that Americans will use self-discipline on the holiday and not engage in activities that could expose themselves and others to the coronavirus.

KImberly Guilfoyle, the girlfriend of the president's son, Donald Trump, Jr., has contracted the virus.

Thirty-one Major League Baseball players and seven staff members have also contracted the infection. The names of the players and teams have not been revealed.

In a preview of what schools and universities across the country could be facing if and when students return to classrooms, the University of Washington in Seattle reports that 117 students residing in 15 fraternity houses have self-reported positive coronavirus test results. The school says it is still verifying the cases and the number could be higher.

Harvard Medical School announced in May that its fall classes would "commence remotely for our entering classes of medical, dental and graduate students." The medical school says on its website, "We hope to have all of our students back on campus by January," but notes that there are "many unknowns."