Live Global Coronavirus News: Antibody Puzzle Complicates Immunity Question

The limits of antibody testing add to the immunity mystery.

One of the great mysteries of the coronavirus pandemic has been the fact that many stricken people have later discovered that they don’t seem to have antibodies, protective proteins that are generated in response to an infection.

This has led to concerns that, without the immunity typically provided by a previous encounter with a virus, people may be susceptible to repeat coronavirus infections.

The complication, writes The Times’s Apoorva Mandavilli, lies in the antibody tests.

Most commercial antibody tests offer crude yes-no answers. The tests are notorious for delivering false positives — results indicating that someone has antibodies when they do not.

But the volume of coronavirus antibodies is known to drop sharply once the acute illness ends, and it has become increasingly clear that tests may produce false-negative results, missing antibodies that are present at low levels.

But declining antibodies, as indicated by commercial tests, don’t necessarily mean declining immunity, several experts said.

“Whatever your level is today, if you get infected, your antibody titers are going to go way up,” said Dr. Michael Mina, an immunologist at Harvard University, referring to the levels of antibodies in the blood. “The virus will never even have a chance the second time around.”

A small number of people may not produce any antibodies to the coronavirus. But even then, they will have “cellular immunity,” which includes T cells that learn to identify and destroy the virus.

“This means that even if the antibody titer is low, those people who are previously infected may have a good enough T-cell response that can provide protection,” said Akiko Iwasaki, an immunologist at Yale University.

For now, many experts urge caution. Without more information about what antibody testing results mean, they said, people should act as though they do not have immunity.

The pandemic is taking an immense toll on the nonprofit groups that Americans rely on for social services, medical care, cultural and spiritual needs: Tens of thousands are likely to close without some kind of rescue package, the research group Candid has concluded from an analysis of tax filings.

The sector is the nation’s third-largest private employer, with 1.3 million nonprofits employing roughly 12.5 million people, about 10 percent of the total in the private sector. A Johns Hopkins University study estimated that 1.6 million nonprofit jobs were lost from February to May.

Hoping to prevent devastating new cutbacks, large nonprofits like the American Heart Association and the American Red Cross are asking for federal grants and loans.

A group of 3,800 nonprofits recently sent a letter asking congressional leaders to increase the tax deduction for charitable contributions. They also asked lawmakers to expand the Paycheck Protection Program and other lending programs to include larger nonprofits, including some Y.M.C.A. chapters, which are left out if they have more than 500 employees.

In the first wave of the outbreak, the 2,600 national outposts of the Y.M.C.A. transformed into civic centers, caring for the children of emergency medical technicians, doctors and other essential workers when day care centers closed down, as well as feeding the poor when schools that offered meal programs shut their doors.

Now the Y.M.C.A. finds itself in financial jeopardy just as it is needed most.

North Korea said on Sunday that it had locked down Kaesong, a city near its border with South Korea, and declared a “maximum” national emergency after finding what its leader, Kim Jong-un, said could be the country’s first case of Covid-19 there.

It issued the high alert after a North Korean who had defected to South Korea three years ago but secretly crossed back into Kaesong last Sunday was “suspected to have been infected with the vicious virus,” the North’s official Korean Central News Agency said on Sunday.

Until now, North Korea, one of the world’s most isolated countries, has repeatedly said that it had no case of Covid-19, although outside experts questioned the claim.

North Korea has taken some of the most drastic actions of any country against the virus, and it did so sooner than most other nations.

It sealed its borders in late January, shutting off business with neighboring China, which accounts for nine-tenths of its external trade. It clamped down on the smugglers who keep its thriving unofficial markets functioning. It quarantined all diplomats in Pyongyang for a month.

A Covid-19 outbreak could seriously test North Korea’s underequipped public health system and its economy, already struggling under international sanctions. Relief agencies have been providing test kits and other assistance to help the country fight any potential spread.

In other news from around the globe:

  • South Korea reported 58 new infections on Sunday, including 46 from abroad, a sharp drop from a day earlier. On Saturday, the country had reported 113 new infections, its highest daily total since March. Those cases included 36 South Korean construction workers who had returned from Iraq, and 32 Russian sailors from a fishing vessel docked for repair.

  • Also in South Korea, the office of President Moon Jae-in said on Sunday that he had received a letter from Bill Gates, the Microsoft co-founder and philanthropist, expressing hope for greater cooperation between South Korea and his foundation in efforts to fight the virus. In the July 20 letter, Mr. Gates praised the country’s pandemic response and said that if the South Korean company SK Bioscience succeeded in developing a vaccine, it would be able to produce 200 million doses a year starting next June. The company has received $3.6 million in research funding from the Bill & Melinda Gates Foundation to develop a coronavirus vaccine.

  • Australia on Sunday reported its highest one-day death toll — 10 people, all in the state of Victoria. Also on Sunday, the New South Wales Supreme Court prohibited a Black Lives Matter rally set for Sydney on Tuesday, citing the risk of virus transmission. Organizers say they plan to appeal.

  • President Jair Bolsonaro of Brazil said on Saturday that he had been cured of Covid-19 after apparently having only mild symptoms from a disease he has repeatedly played down while it has killed more than 85,000 people in his country. “GOOD MORNING EVERYONE,” Mr. Bolsonaro, 65, posted in a message on Twitter Saturday morning, smiling and brandishing a box of hydroxychloroquine pills, the anti-malaria medicine. Mr. Bolsonaro has hailed the drug as a miracle cure, despite a growing scientific consensus that it is not effective to treat Covid-19.

  • Vietnam, which has recorded zero deaths from the coronavirus and had gone 100 days without a single case of local transmission, reported two positive cases over the weekend in the central city of Danang: a 57-year-old man and a 61-year-old man. In both cases, the source of the infection was unclear. Officials said that the second man’s condition was deteriorating rapidly and that he had been hospitalized and placed on a ventilator.

  • As Spain struggles with hundreds of local outbreaks, Britain abruptly imposed a two-week quarantine on returning travelers, particularly from the Spanish northeast. The move by London late Saturday echoed renewed travel restrictions imposed by other European countries, which could further cripple the tourism sector that is a cornerstone of Spain’s economy.

With his sudden embrace of masks and the cancellation on Thursday of the Republican National Convention in Jacksonville, Fla., President Trump has reluctantly conceded to a political landscape that has been transformed by disease and fear, The Times’s Adam Nagourney writes in a news analysis.

A pandemic that first pummeled Democratic states like New York and California has moved with alarming force into red America and helped recast Mr. Trump’s re-election prospects in the contest with Joseph R. Biden Jr., his presumptive Democratic opponent.

Mr. Trump’s attempt to play down the coronavirus, or deride it as a threat exaggerated by his Democratic opponents and the news media, has met the reality of rising caseloads, death counts and overwhelmed intensive care units in places like Arizona, Florida, Georgia and Texas, all states that he won in 2016 and that the Biden campaign had until now viewed as long shots.

“The movement of Covid into the South and West has finally caught up with Trump,” said Linda L. Fowler, a professor of government at Dartmouth College.

The political perils of Mr. Trump’s course were driven home a few hours before he announced he was scrapping the Florida convention. A Quinnipiac poll found that Mr. Biden was leading Mr. Trump in Florida by 13 percentage points, a stunning margin in a state that has become — since the recount in the 2000 presidential election — Exhibit A of a nation where elections are decided by decimal points.

And a Washington Post-ABC News poll this past week found that Americans trusted Mr. Biden over Mr. Trump to handle the Covid-19 crisis by a double-digit margin, 54 percent to 34 percent.

Mr. Trump had little choice but to at least try to change course.

“He’s wearing a mask and canceling the convention,” said Mark McKinnon, who was in charge of advertising for George W. Bush’s re-election campaign in 2004. “That’s a head-snapping reversal for a guy who hates to be wrong, hates to back down and, worst of all, hates to be perceived as weak.”

Steering a course through the ethics of the coronavirus.

Covid-19 has created a whole new set of moral quandaries. Here are a few ways to consider those issues.

Reporting was contributed by Apoorva Mandavilli, Nicholas Kulish, Michael Wilson, Adam Nagourney, Choe Sang-Hun, Jennifer Jett, Fahim Abed, Ernesto Londoño and Raphael Minder.

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