The National Football League announced on Monday that zero players tested positive for COVID-19 from Aug. 12 to Aug. 20

In total, 58,397 tests were administered to 8,573 players and personnel during that time period, the league said in a statement on Monday.

Of the 35,137 tests given to team personnel during that time period, six people were confirmed to be positive, the NFL said.

A teachers’ union in Florida has won an injunction stopping the enforcement of an executive order requiring schools in the state to be open for in-person learning.

In July, Commissioner Richard Corcoran with the Florida Department of Education issued an emergency order that schools must be open at least five days per week for all students. The order was “subject to advice and orders” given by the Department of Health.

The order was for all brick-and-mortar schools to open by Monday, Aug. 31, according to court documents.

The Florida Education Association, which is the state’s largest teachers’ union, filed a lawsuit against Corcoran and Gov. Ron DeSantis in an effort to halt that order.

Tallahassee Circuit Court Judge Charles Dodson granted the union’s injunction request on Monday, ruling that the order from state officials was unconstitutional.

Dodson in his ruling adjusted the emergency order, removing the requirement that the schools be open five days a week and ordering that the day-to-day decision to open or close the schools be left with those most closely associated to the school including the school board and superintendent.

The judge in his ruling also noted how the hearings last week took place over Zoom due to concerns about safety amid the coronavirus pandemic.

New York Gov. Andrew Cuomo announced that certain sports will be allowed to begin practice and playing on Sept. 21 as the state has reached it's lowest infection rate since the pandemic began.

Sports including tennis, soccer, cross country, field hockey and swimming, all considered lower and moderate-risk sports, can begin competitions. Travel for these sports will be prohibited outside the school's region until Oct. 19, the governor said.

The higher-risk sports -- football, wrestling, rugby, hockey and volleyball -- may begin to practice on Sept. 21 but cannot play against other teams. A date for when competitions can take place was not announced.

"The State has done a lot of research on how we can safely have our students participate in school sports and get the exercise they need, and the guidance we developed will allow lower-risk sports to begin practicing and playing next month," Cuomo said.

Schools will have to limit capacity of indoor facilities to 50% and no more than two spectators per player. Those attending will be required to follow proper social distancing guidelines and wear face coverings.

The city of Tuscaloosa, Alabama, will close its bars starting at 6 p.m. on Monday after the University of Alabama reported a rise in COVID-19 cases.

Mayor Walter Maddox signed an executive order restricting all bars from serving alcohol until Sept. 8 -- anyone who violates the order could be fined or sentenced to a maximum of 180 days in the municipal jail.

In a letter to students on Sunday, university President Stuart Bell called the rise in cases on campus to be "unacceptable" and said this is a "critical moment" for the school.

"Make no mistake, this trend is a real threat to our ability to complete the semester on campus," Bell said, adding that "violations to our health and safety protocols" are "subject to harsh disciplinary action, up to and including suspension" from the university.

University police and the Tuscaloosa Police Department will monitor bars, restaurants and off-campus residences where guidelines are not being followed.

ABC News' Janice McDonald contributed to this report.

The University of Hong Kong claims it has documented the world's first case of COVID-19 reinfection.

The university made the announcement in a press release Monday, revealing findings from its study of an "apparently young and healthy patient" who had a second episode of COVID-19 infection which was diagnosed more than four months after the first episode. A team of researchers showed that the genome sequence of the virus strain in the first episode of COVID-19 infection is "clearly different" from that of the virus strain found during the second episode of infection, according to the press release.

Last week, the World Health Organization said there were over 75,000 COVID-19 sequences identified and that they would need to see evidence of individuals who were infected by two different sequences in order to prove reinfection.

There are dozens of studies on COVID-19 immunity being conducted around the world. So far, WHO officials say they have learned that people do develop an immune response to the virus, but it's not completely clear yet how strong that response is and for how long it lasts.

"What we understand from the press release is that this 'may' be an example of reinfection," Dr. Maria van Kerkhove, WHO's COVID-19 technical lead and an infectious disease epidemiologist, said at Monday's news briefing in Geneva.

"It's very important we document this and in countries where sequencing can be done that would be very, very helpful," she added. "But we need to not jump to any conclusions, even if this is the first documented case of reinfection."

ABC News' Christine Theodorou and Karson Yiu contributed to this report.