Worldwide coronavirus cases cross 4 million; more than 2,500 new cases in Florida since reopening Monday

The novel coronavirus pandemic has now killed more than 279,000 people worldwide.

Over 4 million people across the world have been diagnosed with COVID-19, the disease caused by the new respiratory virus, according to data compiled by the Center for Systems Science and Engineering at Johns Hopkins University. The actual numbers are believed to be much higher due to testing shortages, many unreported cases and suspicions that some governments are hiding the scope of their nations' outbreaks.

Since the first cases were detected in China in December, the United States has become the worst-affected country, with more than 1.3 million diagnosed cases and at least 78,794 deaths.

Today's biggest developments:

Here's how the news developed on Saturday. All times Eastern.

7:45 p.m.: Airline union supports temperature checks

Airlines for America, an industry trade organization that represents major U.S. airlines, said it would support temperature checks conducted by the Transportation Security Administration on passengers and customer-facing employees.

The TSA is not currently doing such checks.

"As all screening processes for the traveling public are the responsibility of the U.S. government, having temperature checks performed by the TSA will ensure that procedures are standardized, providing consistency across airports so that travelers can plan appropriately," a release from A4A said.

When asked for comment, TSA said the agency "continues to rely on the health expertise of HHS and the CDC" and that "ongoing discussions with our DHS and interagency colleagues, as well as our airport and airline partners, will enable the agency to make informed decisions with regard to the health and safety of the aviation environment."

This comes after Frontier Airlines, which is not represented by A4A, announced it will implement temperature screenings for all passengers and employees prior to boarding aircraft, making it the first major U.S. airline to announce plans to do so.

5 p.m.: More than 4 million confirmed coronavirus cases

There are now more than 4 million people who have tested positive for the coronavirus around the world, according to data from Johns Hopkins University.

The number of cases rose to 4,004,224 on Saturday afternoon -- more than five months since the coronavirus was first detected in Wuhan, China. The number of confirmed cases passed 1 million on April 3.

Worldwide, over 277,000 people have died and more than 1.3 million have recovered.

3:17 p.m.: Gov. Cuomo's office releases some details of kids who died from COVID-19-like illness

There have been 73 reported cases in New York where children -- predominantly school-aged -- are experiencing symptoms similar to Kawasaki disease and toxic shock-like syndrome possibly due to COVID-19.

The illness has taken the lives of three young New Yorkers including a 5-year-old in New York City, a 7-year-old in Westchester County and a teenager in Suffolk County.

The State Department of Health is now working with the CDC to develop national criteria for identifying and responding to the syndrome.

3:16 p.m.: Government to purchase $3 million of products from farmers

As a part of the USDA's Farmers to Families Food Box Program, next week the government will purchase $3 million worth of products, President Trump announced on Twitter.

President Donald Trump tweeted that the government will make an immense purchase of dairy, meat and produce from the country's farmers, ranchers and specialty crop growers for food lines and kitchens as part of the USDA's Farmers to Families Food Box Program.

3:06 p.m.: California's coronavirus cases continue to increase

As of Saturday, California has reported 2,049 more positive coronavirus cases bringing the state's total to 64,561.

The death toll has also increased Friday as 93 more people have died.

Almost 2,700 people have died from the coronavirus in California.

3:00 p.m.: Texas reports its third-highest daily total of coronavirus cases

Texas reported 1,251 new coronavirus cases on Saturday bringing the state's total to 37,860.

Of the over 37,000 cases, 16,680 are active, 1,735 are hospitalized and 20,141 recovered.

Texas' daily death toll is the second highest in a day since 50 died in one day on April 30. Total fatalities are 1,049, up 45 from Friday.

As Texas' stay-at-home orders are slowly lifting, residents have are hitting the beaches in Galveston, KTRK reported.

1:30 p.m.: Nursing homes deaths now one-third of US fatalities

Nursing home residents have accounted for more than one-third of the 26,000 COVID-19 deaths in the United States, according to an ABC News analysis. There have been more than 77,400 deaths.

The grim figure was compiled from public reporting by health departments in 35 states plus Washington, D.C. The number indicates both the threat elderly people face in crowded buildings and the role that institutional settings have played in the spread of the virus.

The states with the highest percentage of deaths inside nursing homes were Massachusetts, Pennsylvania and Rhode Island, the analysis showed.

Massachusetts has recorded 4,552 total deaths, with 2,739, or 60.2%, inside a nursing home. In Pennsylvania, of the 3,416 total deaths so far, 2,355, or 68.9%, were in a nursing home. Rhode Island has recorded fewer total deaths but a higher percentage -- 280 of 388, about 72% -- in a nursing home.

If the number of total nursing home deaths were adjusted to account for only the states reporting their nursing home data, the deaths would make up 40% of the total U.S. fatalities.

1:12 p.m.: More than 2,500 new cases in Florida since reopening Monday

There have been more than 2,500 new confirmed cases of COVID-19 in Florida since Monday, when the state began to reopen, according to a count by ABC News. There were also 316 new deaths in that same time frame.

Florida now has reported 40,001 confirmed cases, with deaths reaching 1,715, the state's health department said.

Gov. Ron DeSantis allowed most counties in the state to reopen starting Monday, but three -- Miami-Dade, Broward and Palm Beach -- had to wait.

12:22 p.m.: 3 children have died in New York: Cuomo

Three children in New York have died as a result of a syndrome associated with COVID-19, Gov. Andrew Cuomo said.

There are at least 73 cases related to the syndrome in children in the state, according to the governor. The majority affected were infants or elementary school-aged children.

Cuomo said that children have come into hospitals with symptoms similar to Kawasaki disease, a rare inflammatory syndrome typically affecting those younger than 5. The children did not present typical COVID-19 symptoms, such as respiratory distress, but they did test positive for either the virus or the antibodies, meaning they had the virus at some time.

He said the situation was still developing and that health experts are continuing to investigate, calling the matter "truly disturbing."

The New York State Department of Health is working with the U.S. Centers for Disease Control to understand the syndrome in children and will develop national criteria so other states can investigate their own possible cases, the governor said.

The state's health department will also work with the Genome Center and Rockefeller University to conduct a genome and RNA study to better understand who is affected.

"This is the last thing we need. … We still have a lot to learn about this virus and every day is another eye-opening situation," Cuomo said.

He also updated the public on the rate of positive antibodies among frontline workers

Of the FDNY and EMT workers that were part of an antibody study, 17% tested positive, according to Cuomo. It was the highest positive rate among frontline workers. The rate was 14% for transit workers, 12% for healthcare workers and 10% for the NYPD, according to Cuomo.

All of the positive antibody rates in frontline workers fell below the city's overall positive antibody rate, which is 19%.

11:54 a.m.: Air France to require passengers wear masks

Air France is the latest airline to require passengers to wear face masks on flights, a policy that's effective on May 11.

"We recommend that you bring several masks for your travel comfort," the airline said in a statement.

Air France also said that checking passengers' body temperatures will be gradually implemented with a non-contact infrared thermometer.

Delta, American, United, Frontier and JetBlue previously announced they'd require passengers to wear face coverings.

11:19 a.m.: Ivanka Trump's personal aide tests positive, sources say

A personal aide to Ivanka Trump has tested positive for COVID-19, multiple sources familiar with the matter told ABC News.

However, the sources said the aide is not a White House employee, has not been in contact with her for well over a month and has not been near the West Wing.

The news comes after Katie Miller, press secretary to Vice President Mike Pence, and a member of President Donald Trump's personal valet each tested positive.

10:50 a.m.: HHS announces delivery of remdesivir

The Department of Health and Human Services announced the agency is sending out more remdesivir to hospitalized patients after a week of frustration from doctors who said they couldn't access it.

Remdesivir will be used to treat patients with COVID-19 and has been touted by both President Donald Trump and infectious disease expert Dr. Anthony Fauci as promising, based on early data. The drug was donated by Gilead, which developed it, and will be delivered to Connecticut, Illinois, Iowa, Maryland, Michigan and New Jersey, according to the HHS.

Illinois and New Jersey will receive the biggest shipments, with 140 cases and 110 cases respectively, according to the agency. Each case contains 40 vials of the drug.

The shipments, which began Thursday evening, come after doctors said they could not access the drug and it was not being delivered to the hospitals that needed it most.

Remdesivir initially was developed by Gilead to treat Ebola. Although initially promising, it didn't prove as effective as other Ebola treatments, so research was halted. Early data from the drug used for COVID-19 patients has been promising, but experts warned that data is still limited.

10:15 a.m.: FDA authorizes 1st antigen test with rapid results

The Food and Drug Administration has authorized the first test that can rapidly detect if a person has the virus that causes COVID-19, and has the ability to test millions of Americans per day.

The antigen test can produce results within minutes, according to the FDA, and some experts believe it is better for mass testing than the PCR test, which is the current diagnostic test that can detect an active COVID-19 infection.

The agency described the antigen test as "important in the overall response against COVID-19" because they can generally be produced at a lower cost and "once multiple manufacturers enter the market, can potentially scale to test millions of Americans per day due to their simpler design, helping our country better identify infection rates closer to real time."

However, the FDA also noted downfalls of the antigen tests. While the tests produce highly accurate positive results, there is also a higher chance they produce false negatives than PCR tests.

The FDA said a negative results from an antigen test does not rule out an infection and may need to be confirmed with a PCR test.

This is the first antigen test to be authorized, but more will follow, according to the FDA.

7:40 a.m.: FDA head self-quarantines

Food and Drug Administration Commissioner Stephen Hahn will self-quarantine for 14 days after he came into contact with an individual who tested positive for COVID-19, a statement from the FDA confirmed.

"As Dr. Hahn wrote in a note to staff yesterday, he recently came into contact with an individual who has tested positive for COVID-19. Per CDC guidelines, he is now in self-quarantine for the next two weeks. He immediately took a diagnostic test and tested negative for the virus," the statement read.

Hahn is believed to have come into contact with Vice President Pence's top spokesperson Katie Miller, who tested positive for COVID-19, reported Politico.

The FDA did not confirm whether Miller was the individual with whom Hahn came into contact.

6:07 a.m.: Gig workers, self-employed still shut out of unemployment benefits in 11 states

For the first time, Uber drivers, personal trainers, babysitters — all non-traditional wage earners that the government estimates to be at least a third of the American workforce — could apply for unemployment benefits after the CARES Act signed into law on March 27.

But in at least 11 states as of Friday, these Americans hadn't received any kind of unemployment payments. In nine states, they hadn't even been able to apply for it.

This news comes on the heels of record-breaking unemployment for April, with at least 20.5 million jobs lost.

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In New Hampshire, Wisconsin and Arkansas, it's unclear if any gig workers or independent contractors have received unemployment benefits, even though tens of thousands of applications have been accepted.

And in Arizona, Delaware, Hawaii, Illinois, Kansas, Maine, Maryland, Nevada and Ohio, there is no way for these self-employed Americans to even for unemployment. More than a month after the CARES Act passed, these states do not have the online portals up and running.

States have had to build new systems to approve people for this federally funded unemployment -- known as Pandemic Unemployment Assistance -- and there's a slew of reasons they've been bogged down. Some were waiting for federal guidance, while others were waiting on tech infrastructure.

5:32 a.m.: Sen. Ted Cruz gets haircut from previously jailed salon owner

Texas Sen. Ted Cruz revealed Friday that he got a fresh new haircut from the salon owner who recently made national headlines when she was jailed for refusing to close her store.

"Thank you to Shelley Luther and the team at Salon a la Mode for giving me my first haircut in 3 months & more importantly for standing up for liberty and common sense," Cruz tweeted Friday evening. "Your courage helped pave the way for more #TX businesses to re-open & for more people to get back to work today."

Luther defied an executive order to shut down her business and kept her salon open despite a citation, a cease-and-desist letter and a restraining order.

"The rule of law governs us. People cannot take it upon themselves to determine what they will and will not do," Dallas Civil District Judge Eric Moyé said during her hearing on Tuesday.

Luther, who was ordered to serve seven days in jail for contempt of court, was released Thursday after a decision by the Supreme Court of Texas.

Following the court's decision, Texas Gov. Greg Abbott issued an executive order to eliminate jail time for those who violate similar orders, calling such actions "excessive."

What to know about coronavirus:

ABC News' Cheyenne Haslett, Trish Turner, Sophie Tatum, Meredith Deliso, Eric Strauss, Ben Gittleson, John Santucci, Katherine Faulders, Aicha El Hammar, Scott Withers, Matthew Mosk, Olivia Rubin and Allison Pecorin contributed to this report.