The latest on the coronavirus pandemic

The US Food and Drug Administration has issued emergency use authorizations for the first two Covid-19 serology tests that can tell not only whether someone has antibodies to the virus, but can give some idea of how much antibody is there.

The tests, the ADVIA Centaur COV2G and Attelica COV2G, are both from Siemens, the FDA said. Like other serology tests, these tests detect the body's immune response to the infection caused by the virus rather than detecting the virus itself.

“There are still many unknowns about what the presence of SARS-CoV-2 antibodies may tell us about potential immunity, but today’s authorizations give us additional tools to evaluate those antibodies as we continue to research and study this virus,” Stenzel said.

“Patients should not interpret results as telling them they are immune, or have any level of immunity, from the virus,” he added.

There are not nearly enough Americans using masks to bend the curve on the coronavirus infection rate, the head of one of the main teams forecasting the pandemic said Friday.

The University of Washington’s Institute for Health Metrics and Evaluation (IHME) revised its forecast this week for coronavirus deaths because of rising infection rates and because too few Americans were using face masks regularly, IHME’s Dr. Chris Murray told CNN.

This week’s IHME forecast of 230,822 US deaths from the virus by November is up about 11,000 from last week’s projection of 219,864 deaths.

The model projects that if almost all Americans wore face masks, the number of deaths by November would drop by around 32,000, to just below 199,000 deaths.

Murray says the “good news” is that cases are peaking in Florida, Texas, California and somewhat in Arizona, which is bringing their numbers down a bit.

“But we're seeing numbers going up faster in a whole series of states in the Midwest. And that's driving up our numbers. Places, also, like Georgia and North Carolina are going up faster than we expected,” he said.

A source within the Miami Marlins has told CNN that the team has a total of 21 members who have tested positive for Covid-19 over the last week. The breakdown in total is 18 players and three coaches.

The source told CNN those members who have tested positive for coronavirus are currently traveling on several sleeper buses headed for South Florida for additional screening and testing. Major League Baseball health officials approved the move. 

The Marlins have been isolating and quarantining in a team hotel in Philadelphia, Pennsylvania, since Sunday. Members of the team who have not tested positive remain in Philadelphia.

Colombia recorded 295 new coronavirus-related deaths on Friday, raising the total death toll to 10,105, the country's health ministry said.

The ministry also reported 9,488 new coronavirus cases, bringing the total to 295,508.

Colombia’s capital Bogota is the biggest hotspot in the country with more than 101,000 cases of infection so far.

Some context: President Ivan Duque recently extended the country's coronavirus lockdown through Aug. 30, but said the cities with low Covid-19 rates would continue to partially reopen various economic sectors.

ESPN is reporting that Major League Baseball commissioner Rob Manfred warned players union head Tony Clark on a Friday call that if the league and players don’t do a better job following Covid-19 protocols and better manage the virus, Manfred could shut down the shortened season.

On Friday, both the MLB and MLB Players Association announced that 29 players and staff have tested positive for Covid-19 this week. 

CNN has reached out to the league for comment but has not heard back. A union spokesperson told CNN no comment.

Wearing personal protective equipment (PPE) when caring for patients with Covid-19 isn’t enough to completely eliminate the threat from the virus for frontline workers, according to a new study from King’s College London.

Health care workers with adequate gloves, gowns and face masks, still had 3.4 times the risk of contracting the coronavirus compared to the general population, the study found, and minority health care workers had an even greater risk of testing positive.

African American, Latinx and other minority care providers were 5 times more likely to contract Covid-19 than their White counterparts, the study found.

“A little over 20 percent of front-line health-care workers reported at least one symptom associated with SARS-CoV-2 infection compared with 14.4 percent of the general population; fatigue, loss of smell or taste, and hoarse voice were especially frequent,” the researchers wrote. 

The researchers used the COVID Symptom Tracker app to study the data of more than 2 million people, including almost 100,000 frontline health care workers in the United States and the United Kingdom between March 24 and April 23. 

They found more than 2,700 cases of Covid-19 per 100,000 health care workers compared with just over 240 cases per 100,000 among the general population. 

“The data is clear in revealing that there is still an elevated risk of SARS-Co-V-2 infection despite availability of PPE,” said King’s College London professor and senior study author Sebastien Ourselin.

Not only did researchers find that minority health care workers had an increased risk of Covid-19 infection, they also found that they were more likely to report a lack of adequate PPE and to say they were forced to frequently reuse equipment, Ourselin said.

Previous studies have found that 10-20% of coronavirus infections occur among frontline workers.

“Our study provides a more precise assessment of the magnitude of increased infection risk among healthcare workers compared to the general community,” said Dr. Andrew Chang, a senior study author and director of cancer epidemiology at Massachusetts General Hospital.

At the time the study was conducted, health care providers in the US and the UK were experiencing severe shortages in gloves, gowns and face masks. The authors said the results of a similar study now might be different.

“Many countries, including the US, continue to face vexing shortages of PPE,” Chang said. “Our results underscore the importance of providing adequate access to PPE and also suggest that systemic racism associated with inequalities to access to PPE likely contribute to the disproportionate risk of infection among minority frontline healthcare workers.”

The research suggests health care systems should ensure adequate availability of PPE and develop additional strategies to protect health-care workers from COVID-19, particularly those from Black, Asian, and minority ethnic backgrounds. 

The study was published Friday in the journal Lancet Public Health.

A study that showed more than 40% of kids at a Georgia summer camp caught coronavirus is a taste of things to come when schools reopen, an infectious disease specialist said Friday. 

The report, published by the US Centers for Disease Control and Prevention earlier Friday, found that at least 44% of campers and counselors at the overnight camp became infected with the virus.

Saag said schools will need to take precautions to keep students, staff and their families safe from infection. That means keeping students and staff masked at all times in school, keeping students distanced from one another in classrooms, and improving ventilation inside schools.

“Business as usual isn’t going to work,” Saag said.

Asked if schools should invest in air cleaners or purifiers, Saag said they are unlikely to be worth the expense.

“I think what is more important is the immediate environment around each student,” he said.

Air purifiers are too far away to help with any virus being passed between students.

“If we keep distance between them, and if everyone is wearing a mask, that is our best chance to mitigate,” Saag said.

Brazil reported 52,383 new coronavirus cases in the last 24 hours, bringing the country's total to 2,662,485, its health ministry announced Friday.

This is the third consecutive day Brazil reported more than 50,000 new Covid-19 cases.

In addition, the ministry announced 1,212 new fatalities related to the virus, raising the total death toll to 92,475.

Texas has reported 8,839 new Covid-19 cases on Friday, bringing the total number of cases to 420,946 in the state. 

The state also reported 295 Covid-19-related deaths, bringing the total number to 6,569. 

Texas' health department recently reported that it had "improved" its Covid-19 fatality reporting. Texas Covid-19 fatalities are now counted from death certificates instead of local reports.

Note: These numbers were released by the Texas Department of State Health Services, and may not line up exactly in real time with CNN's database drawn from Johns Hopkins University and the Covid Tracking Project.