Coronavirus live updates: FDA clamps down on antibody tests as former chief questions their reliability

Pharmaceutical companies continue to make headlines as governments and investors hang their hopes on a steady recovery from the Covid-19 pandemic. Gilead Sciences CEO Daniel O'Day said Sunday the company would be donating its entire supply of remdesivir to treat coronavirus patients. Roche Chairman Christoph Franz said the drugmaker will invest more than $437 million in a German testing site. Another week of quarterly reports lies ahead, and more retail locations are reopening as U.S. states loosen lockdown restrictions.

This is CNBC's live blog covering all the latest news on the coronavirus outbreak. All times below are in Eastern time. This blog will be updated throughout the day as the news breaks. 

• Global cases: More than 3.5 million
• Global deaths: At least 247,752
• US cases: More than 1.1 million
• US deaths: At least 67,686

The data above was compiled by Johns Hopkins University.

The Food and Drug Administration said it is tightening rules for antibody tests after it became aware of "a concerning number" of tests performing poorly or being marketed inappropriately.

Manufacturers will need to submit emergency use authorization forms and data proving the tests work within 10 days or face possible removal. So far, 12 antibody tests have been authorized by the FDA for emergency use, and more than 250 tests are currently the subject of a pre-EUA or EUA review, FDA Commissioner Stephen Hahn told reporters Monday.

Antibody tests can indicate whether a person has had Covid-19 in the past and was either asymptomatic or recovered. U.S. officials and businesses have been pouring money into antibody testing, hoping it will give people the confidence to return to work and reopen parts of the economy. —Berkeley Lovelace Jr., Will Feuer

Tim Bray, a senior software engineer and vice president at Amazon Web Services, resigned from the company, citing Amazon's move to fire outspoken critics of its labor practices. 

In a blog post, Bray said his last day at the company was May 1. He said he strongly disagreed with Amazon's decision to fire several workers who criticized the company's climate stance and, most recently, its treatment of warehouse workers amid the coronavirus. 

"I quit in dismay at Amazon firing whistleblowers who were making noise about employees frightened of Covid-19," Bray wrote, adding that "remaining an Amazon VP would have meant, in effect, signing off on actions I despised. So I resigned." 

Amazon warehouse workers and corporate employees have participated in a string of protests over the past few months to call for the company to better protect workers. The workers want Amazon to shut down facilities where there are positive cases and provide paid sick leave, among other things. 

Amazon has previously said it has gone to "great lengths" to keep facilities clean and make sure employees are following the necessary precautions. In the company's latest earnings report, Amazon said it would invest its expected $4 billion second-quarter profit in coronavirus-related efforts, such as purchasing additional safety gear for workers and building out its coronavirus testing capabilities. —Annie Palmer

Automakers with plants in southern states are reopening and slowly beginning to produce vehicles.

Daimler started to produce Mercedes-Benz models last week in Alabama and on Monday BMW confirmed the reopening of its plant in South Carolina.

Hyundai Motor and Kia Motors, which operate separately in the U.S. but have the same South Korean parent company, also confirmed they reopened plants Monday in Alabama and Georgia, respectively.

The facilities, according to the automakers, have implemented new and increased safety and sanitization protocols in an attempt to lower the spread of Covid-19. They also are not operating at normal levels.

Other automakers such as Toyota Motor are expected to begin reopening their plants in the coming weeks. General Motors, Ford Motor and Fiat Chrysler are among the automakers to not yet announce a restart date following delays to previous restart dates. —Michael Wayland

New York City Mayor Bill de Blasio announced that the city will give away 7.5 million face coverings, free of charge, to residents at local parks, grocery stores and other city locations.

New Yorkers have "overwhelmingly" complied with the Gov. Andrew Cuomo's executive order requiring all residents to wear a face covering when in public, but the city is going to step in to further provide face coverings to people who may not have the means to obtain one, de Blasio said.

The free face coverings the city plans to distribute effective immediately will not be non-medical and won't be the same masks used by health-care workers, however, they will still be reusable and effective as long as they remain dry, he said. —Noah Higgins-Dunn, Jasmine Kim

Carnival Cruise Line said it will resume North American service on August 1, becoming the first major cruise line to restart operations as the pandemic continues to spread.

Attention will be focused on bookings for the early cruises as analysts and industry insiders contemplate how resilient the demand for cruising is after multiple ships became the sites of Covid-19 outbreaks that infected thousands and killed dozens.

Jackie Ceren, a travel agent based out of Florida, said she has clients who have been waiting to book for weeks. However, she has doubts about whether the U.S. has contained the virus and whether the company will be able to sail come August.

"It's going to all depend on what's happening with this virus. I do have people waiting. People do really want to get back on ships," she said. "But if people book and they end up having to cancel these cruises, no one's going to be happy. [Carnival is] making it worse, I think." —Will Feuer

Salesforce announced a handful of new tools aimed at helping businesses and community leaders reopen safely amid the coronavirus pandemic.

The tools, available on Work.com, will include items such as contact tracing, a resource center and a system to manage employee shifts to adhere to social distancing.

"We are capturing the best advice, the best words from doctors and tremendous business organizations who are telling businesses of safe ways to reopen," Salesforce CEO Marc Benioff told CNBC's "Squawk on the Street." "When we go back to work there's things we're going to have to do differently." —Jessica Bursztynsky

Dr. Scott Gottlieb told CNBC's "Squawk Box" that he does not trust the results from a single Covid-19 antibody test. Concerned about rates of false positives, the former FDA chief said he recommends people take multiple tests to ensure accuracy.

"Quite frankly, if it was me, I would repeat it three times," said Gottlieb, a CNBC contributor who sits on the boards of Pfizer and biotech company Illumina. "I know they're expensive but I wouldn't put confidence in any one test." —Kevin Stankiewicz

Home improvement retailer Lowe's is handing out a second round of bonuses to employees helping customers stock up on supplies for home repairs and do-it-yourself projects during the pandemic.

The company said it'll spend $80 million on special payments to its hourly employees. All full-time hourly employees will get a $300 payment and part-time and seasonal employees will get $150. It gave similar special payments to employees in late March.

Starting Monday, Lowe's said it will require all employees to wear a mask or face covering while working at stores and visiting customers' homes. It is providing masks and gloves to employees.

Lowe's is one of the retailers that's kept stores open during the pandemic as an essential retailer. In an interview with CNBC in late March, CEO Marvin Ellison said customers have turned to the company as they replace appliances, do DIY projects, or buy other items that help them during extended stays at home, such as larger freezers or new water heaters. —Melissa Repko

Nearly three-fourths of small business owners say the Covid-19 outbreak will likely have permanent effects on the way they run their businesses, according to the CNBC|SurveyMonkey Small Business Survey.

"Most small businesses were in rapid growth mode in January. ... 2019 was roaring for lots of small businesses," said Marilyn Landis, who runs small business consulting firm Basic Business Concepts.

The pandemic — and the shelter-in-place orders that followed — quickly put the brakes on that business boom. CNBC's Eric Rosenbaum reports the survey found that 62% of small business owners said demand for their products and services has fallen in the past two months, with 42% saying demand decreased "a lot." —Terri Cullen

Grocery workers across the country may soon have an easier time getting coronavirus testing.

Kroger said it's expanding employees' access to Covid-19 testing by providing employees with free self-administered kits or an appointment at one of its drive-thrus, if they have symptoms or medical need. Kroger is the parent company of many grocery chains, including Fred Meyer and Fry's, and has more than 460,000 employees.

As grocery workers continue to stock shelves, check out customers, or fulfill online orders during the pandemic, some have gotten sick and died.  Grocers have announced a growing number of safety measures to try to prevent the spread of the virus in stores, such as providing masks for workers, installing Plexiglass dividers, and encouraging social distancing with signs. A major grocery union also encouraged shoppers to wear masks and limit trips to the store. —Melissa Repko

General Electric's aviation unit plans to slash its workforce by 25% this year as the coronavirus pandemic threatens demand for new aircraft. The 13,000 job cuts will be permanent and include involuntary measures and voluntary ones like early retirements.

General Electric is doubly exposed to the aviation slump through both the GE Aviation manufacturing arm and its leasing unit, one of the largest aircraft lessors in the world.

"To protect our business, we have responded with difficult cost-cutting actions over the last two months. Unfortunately, more is required as we scale the business to the realities of our commercial market," David Joyce, CEO of that GE unit, told employees in a memo. —Melodie Warner 

More than 30 million small businesses — the lifeblood of the U.S. economy — are on the ropes amid the coronavirus pandemic, and the government loan programs designed to help them aren't doing the job, a CNBC/SurveyMonkey Small Business Survey found.

The $660 billion Paycheck Protection Program (PPP), part of the CARES Act, was meant to provide a lifeline for businesses suffering through the economic shutdown, but only 13% of respondents who applied for PPP were able to obtain loans, the survey found. Among all respondents, just 7% have already received financing and 18% are still waiting for a response from a lender.

CNBC's Lori Ioannou delves into the reasons behind the struggles small businesses are having in trying to obtain financial support. —Terri Cullen

Most states have already closed public schools through the remainder of the academic year. Of those that haven't, no state has set a date to reopen them.

Reopening schools is arguably the most essential complication to overcome for an economic recovery as many parents simply can't go back to work if their children are still home. Unless plans are thoughtful and nearly foolproof, parents won't be comfortable putting their children at risk.

The United Federation of Teachers union, which represents more than 140,000 teachers and other school employees in New York City, has started an online petition addressed to the federal government demanding certain requirements are met before schools can reopen. They include widespread testing, temperature checks upon entering schools, rigorous cleaning protocols, and a procedure for tracing people who have been in close physical contact with anyone who has tested positive for the virus. —Melodie Warner 

The global economy is most likely set for a U-shaped recovery with a "jagged bottom" after the coronavirus crisis, according to HSBC.

Speaking to CNBC Monday, Head of Global Foreign Exchange Strategy David Bloom outlined the bank's game plan in the event of L-, U- and V-shaped recoveries, emphasizing that analysts should be making plans for all eventualities.

In a U-shaped scenario, the economy fails to respond immediately to exits from lockdowns around the world, but the expectation for a delayed rebound remains in place with multiple "false dawns," Bloom suggested, causing a "jagged bottom" to the U curve. —Melodie Warner 

Clothing apparel company J.Crew filed for bankruptcy protection, making it the first major retail bankruptcy of the coronavirus pandemic. The New York-based retailer had already been struggling under a heavy debt load and sales challenges.

The company said it reached a deal with stakeholders to convert  $1.65 billion of its debt to equity. It also secured $400 million in financing from existing lenders Anchorage Capital Group, GSO Capital Partners, and Davidson Kempner Capital Management to help fund operations through bankruptcy. —Melodie Warner 

Tyson Foods reported a fiscal second-quarter decline in net income of 15% year over year, sending the company's shares down 5% in premarket trading. 

Tyson temporarily closed plants amid the Covid-19 outbreak after hundreds of workers tested positive for the virus. The company expects higher production costs and lower productivity as it attempts to ramp back up. Read more about Tyson's fiscal second quarter and coronavirus response from CNBC's Amelia Lucas. —Sara Salinas

People who have recovered from Covid-19 are "very likely" to be immune to the virus, according to Roche CEO Severin Schwan. 

"We know from other coronaviruses that it's very likely as soon as you have gone through an infection you will also acquire immunity," he said on CNBC's "Squawk Box Europe," adding that more research is needed. "We need studies to really see whether those people who have been infected once are subject to reinfection. But there's a high likelihood that this will be the case." —Chloe Taylor

Swiss drugmaker Roche will invest more than 400 million euros ($437 million) in a German testing site, according to Reuters. Roche Chairman Christoph Franz said the investment will include making antibody tests in order to detect people who have already been infected with the virus and recovered. 

Franz said the drugmaker will invest in its biochemical production facility in Penzberg, as well as in additional diagnostics research and development, Reuters reported. —Sara Salinas

The reproduction rate of the coronavirus in Germany is currently estimated at 0.74 on average, Health Minister Jens Spahn said, Reuters reported.

The reproduction rate refers to how many people could be expected to be infected by someone with the virus, on average. Health authorities want to keep that number below 1 so the spread of the virus gradually slows. —Holly Ellyatt

The number of deaths from the coronavirus in Spain reached 25,428, up from 25,264 the previous day, its health ministry said. That marks a daily increase of 164 deaths.

Spain has recorded 218,011 cases of the virus, the second-highest total from any country, after the U.S. —Holly Ellyatt

Prime Minister Shinzo Abe has decided to extend Japan's state of emergency to May 31.

Abe said he will consider lifting the emergency without waiting for its May 31 expiration if experts decide is possible based on regional infection trends, according to Reuters. —Holly Ellyatt

Activity in the euro zone's manufacturing sector contracted at a record rate in April with Covid-19 related measures impacting heavily on demand and production, a survey showed.

IHS Markit's Purchasing Managers' Index for manufacturing fell to 33.4 in April from 44.5 in March, the final PMI data showed Monday. It's slightly lower than preliminary data estimating a decline to 33.6. The 50-point mark separates monthly expansion from contraction.

"Below the earlier flash reading, the latest PMI was the lowest ever recorded by the series (which began in June 1997), surpassing readings seen during the depths of the global financial crisis and indicative of a considerable deterioration in operating conditions," IHS Markit said.

"Output, new orders, export sales, and purchasing activity all fell at record rates, whilst supply-side constraints intensified to an unprecedented extent. Confidence about the future sank to a fresh series low." —Holly Ellyatt

The number of new cases in Russia has risen by 10,581 over the past 24 hours, its crisis response center said. That compares to a daily increase of 10,633 that was recorded on Sunday.

Russia's total number of cases has reached 145,268 and it has recorded 1,356 deaths. Russia has now become the seventh-worst-hit country in terms of infections, Johns Hopkins University data shows. Russian Prime Minister Mikhail Mishustin was diagnosed with the coronavirus just last week. —Holly Ellyatt

Read CNBC's coverage from CNBC's Asia-Pacific and Europe teams overnight here: Russia sees over 10,000 new cases; Euro zone manufacturing slumps in April