Covid-19 Survivors Have a Low Risk of Reinfection, Study Suggests

Illustration for article titled Covid-19 Survivors Have a Low Risk of Reinfection, Study Suggests

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New government-funded research this week should offer some comfort to people who have survived covid-19. It suggests they have a low risk of reinfection from the coronavirus, at least around three months later.

Researchers at the National Cancer Institute teamed up with commercial testing labs and two healthcare data collection companies for this study, published Wednesday in JAMA Internal Medicine.

They analyzed de-identified data from more than 3 million Americans who had gotten a commercial antibody test for SARS-CoV-2, the coronavirus that causes covid-19, sometime between January to August 2020. Antibody tests, while not perfect, indicate whether someone has had a prior recent infection. These people were divided into those who had antibodies and those who didn’t, based on testing. Then the researchers looked at how many people in both groups later got a PCR test for covid-19, which is meant to diagnose an active infection.

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About 10% of people in each group went on to get a PCR test. More people with antibodies tested positive for the virus within the first 30 days after their antibody test than those without antibodies. But that’s not surprising, since detectable traces of the virus can remain in the body for months, even after symptoms have passed and the person is no longer infectious. So it’s likely these positive PCR results were usually picking up the first infection. When the researchers looked specifically at the positive test rate after the first month and especially more than 90 days later—enough time for a positive PCR test to likely indicate a true reinfection—the results were encouragingly different.

After three months or longer, only 0.3% of people with an earlier positive antibody test tested positive for the coronavirus again, compared to 3% of those with a negative antibody test. In other words, having a past infection was linked to a much lower risk of infection three or more months later.

“People who have recovered from covid-19 should be reassured that being antibody-positive is associated with some protection against a new infection,” study author Douglas Lowy, the principal deputy director of the NCI, said in an email.

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The findings do come with their limitations, though. For one, they can’t tell us exactly how much protection a past infection will provide against reinfection, or how long it’s expected to last (though other research has suggested that it may be years). Another factor this study can’t account for is the recent emergence of coronavirus variants. Some—like the one first identified in South Africa last year—are thought to raise the risk of reinfection, since they may be able to partly evade the immune response created by an earlier infection or vaccination.

Still, there’s no research showing that any currently spreading variants can completely evade someone’s natural or vaccine-provided immunity. Our immune system has plenty of weapons against a familiar germ, and it’s likely that most reinfections will turn out to be milder than the first time.

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Even before these new variants were around, though, there had been documented cases of reinfection, including cases where symptoms were worse the second go-around. And the new study’s findings still suggest that reinfection does happen, if rarely. So no one should assume they’re impervious to covid-19 just because they survived an earlier infection with no problem. Ultimately, the best way to keep everyone safe from covid-19 is to vaccinate as many people as possible, including those who have already had the viral illness, according to Lowy. It’s a remedy that involves a lot less risk than getting a natural infection.

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“People who have recovered from covid-19 should still plan to be vaccinated when they have the opportunity,” he said.

The NCI plans to continue funding research that will track the prevalence of reinfection in the general public, along with studies that will look at how our immune response to the virus may change over time and against new variants.

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A Woman’s Tragic Covid-19 Death Traced to Tainted Donated Lungs, Report Finds

Illustration for article titled A Woman's Tragic Covid-19 Death Traced to Tainted Donated Lungs, Report Finds

Photo: Christopher Furlong/ (Getty Images)

Doctors say that a Michigan woman’s untimely death last fall was caused by covid-19 unknowingly spread through a double lung transplant. It’s likely the first clear case of covid-19 linked to transplantation. Another doctor contracted the viral illness through the procedure, but survived.

The woman’s tragic case was detailed in a report published earlier this month by doctors at the University of Michigan Medical School, in the American Journal of Transplantation. According to the report, the woman needed the transplant because of her chronic obstructive pulmonary disease. Her donor was a woman who had recently died of severe brain injury from a car accident. Standard screening, including a nasal and throat swab test for the coronavirus (SARS-CoV-2) on the donor and recipient, turned up nothing unusual and the procedure appeared to go off without a hitch.

Three days following the transplant, however, the recipient spiked a fever and began to have trouble breathing. A nasal swab test initially showed no traces of the coronavirus, but she obviously had pneumonia and a later direct test of her lungs came back positive for the virus. Over the next two months, the woman’s condition only worsened, and she developed septic shock. Though she was treated with antivirals, convalescent plasma, and ECMO (a last resort medical device that takes over for the heart and lungs), the woman succumbed to her illness 61 days after her transplant.

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The donor had no history indicating recent exposure to the coronavirus or symptoms of covid-19 prior to her death, along with a negative nasal swab test. But doctors had held onto a fluid sample collected from her lungs and when they tested it after the recipient became sick, it came back positive. Genetic sequencing of the virus found in both the donor and recipient showed they were nearly identical, effectively proving the recipient’s infection came from the tainted lungs. A third person—one of the woman’s surgeons who handled the lungs—became sick and tested positive for the virus soon after the procedure, and this infection was also traced back to the donated lungs. The surgeon recovered, however, and no other member of the transplant team was affected.

There have been other suspected cases of covid-19 spread through transplantation, but this is thought to be the first known case to demonstrate transmission by using genetic sequencing. Despite the tragedy of this death, however, it’s likely still an incredibly rare risk. This same month, scientists with the Centers for Disease Control and Prevention looked into eight suspected cases of covid-19 linked to organ donation documented between March to May 2020. They ultimately concluded that the most likely source of transmission in these cases “was community or healthcare exposure, not the organ donor.”

Rare as it might be, the Michigan doctors do think more can be done to ensure the safety of organ recipients and their doctors during this time, particularly when lungs are being transplanted.

“Transplant centers and organ procurement organizations should perform SARS‐CoV‐2 testing of lower respiratory tract specimens from potential lung donors, and consider enhanced personal protective equipment for health care workers involved in lung procurement and transplantation,” they wrote.

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China Deploys Anal Swabs for Covid-19 Testing, Says It’s More Accurate

Medical workers are seen at a Covid-19 coronavirus testing site in Beijing on January 23, 2021.

Medical workers are seen at a Covid-19 coronavirus testing site in Beijing on January 23, 2021.
Photo: Noel Celis (Getty Images)

Health authorities in China have deployed anal swab tests to detect covid-19 in the lead up to the Lunar New Year celebrations, according to the Chinese state media outlet the Global Times, a technique that some claim might be more accurate than traditional nasal swabs, throat swabs, and antibody tests. But not everyone is convinced anal swabs are necessarily better.

The Global Times cites Li Tongzeng at Beijing You’an Hospital, a proponent of anal swabs who claims that “the coronavirus survives longer in the anus or excrement than those taken from upper body tracts,” noting the anal swabs are only being taken in a relatively limited capacity.

But the method might be a little more common than Li is letting on. Anal swabs are being deployed in Beijing quarantine as well as in some school settings, according to recent reports out of Beijing’s Daxing district.

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From the South China Morning Post:

The mass testing was conducted after the capital went into partial lockdown in Daxing and Shunyi, with genetic sequencing revealing two cases of the more transmissible coronavirus variant discovered last month in Britain.

The capital has since been on high alert.

More than 1,200 people were tested at a school attended by one pupil with an asymptomatic case of the British strain. Each of the contacts at the school had nasal, saliva and anal swabs as well as serum tests – all of which were negative.

Needless to say, an anal swab isn’t as convenient as a throat swab or a nasal swab, and there are no reports of other countries that are prioritizing anal swabs for covid-19 tests. The jury is still out on whether anal swabs, which reportedly take about 10 seconds, are more useful than a regular throat swab to test for coronavirus.

ABC News in Australia reports the “invasive” new test is being used outside of Beijing in places like the city of Guangzhou, where one social media user reported her anal swab was administer on her 14th day of quarantine. She also got an oral swab, according to the news outlet. Another social media user in Beijing said the anal swab test made her feel ashamed.

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“Just endless shame. No other feelings. Good luck,” the student, reportedly from South Korea, wrote about the swab in China.

But it’s not clear how much good these tests are going to do during the covid-19 pandemic—at least according to experts in other countries who question the necessity of the practice.

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“I’m not quite sure what they’re trying to achieve here with all the anal swabs,” Dr. Sanjaya Senanayake told ABC News.

China has seen a recent resurgence of coronavirus in a handful of hotspots, a troubling development as mutant variations from the UK and South Africa have been show to be more contagious. But China is still doing much better than most countries in the world at containing the pandemic, all things considered.

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This week the world surpassed the grim milestone of 100 million cases, with over 2.15 million deaths, a likely undercount of the true death toll around the world.

The U.S. has reported 25.4 million cases and more than 425,000 deaths since the pandemic began, according to the Johns Hopkins University coronavirus tracker. The U.S. identified over 143,000 new cases and 3,734 deaths on Tuesday alone.

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