The Children Never Had Covid. So Why Did They Have Coronavirus Antibodies?

first_imgThen why do we have a pandemic? Shouldn’t most of us be protected by memory cells left by other coronavirus infections? – Advertisement – Now the researchers are planning to expand their study to monitor thousands of children and adults. Some have antibodies that can block the new coronavirus in lab tests. Others do not.“If they have the pandemic strain, are they protected?” Dr. Kassiotis asked. Will they get sick, he wondered, or will the infection be all but undetectable?Dr. Elledge and his colleagues at Harvard developed their own highly specific, sensitive and exhaustive antibody test, VirScan. It is able to detect a diverse collection of antibodies with that are directed at any of more than 800 places on the new coronavirus, including the antibody that Dr. Kassiotis and his colleagues studied.After examining blood taken from 190 people before the pandemic emerged, Dr. Elledge and his colleagues concluded that many already had antibodies, including the one targeting the base of the spike — presumably from infections with related coronaviruses that cause colds.But while adults might get one or two colds a year, Dr. Elledge said, children may get up to a dozen. As a result, many develop floods of coronavirus antibodies that are present almost continuously; they may lessen cold symptoms, or even leave children with colds that are symptomless but still infectious.While adults may not have detectable coronavirus antibodies, many may be able to quickly make antibodies if they are infected with a coronavirus.In typical viral infections, the immune system pours out antibodies to fight the virus. When the infection is quelled, the antibodies, no longer needed, diminish in number. But the body is left with so-called memory cells that allow antibody production to soar rapidly if the virus tries to invade again. The Coronavirus Outbreak ›Words to Know About TestingConfused by the terms about coronavirus testing? Let us help: In a study published Friday in Science, the group, led by George Kassiotis, who heads the Retroviral Immunology Laboratory at the institute, reports that on average only 5 percent of adults had these antibodies, but 43 percent of children did.Researchers who did not participate in the study were intrigued by the finding. H. Benjamin Larman, an immunologist at Johns Hopkins School of Medicine, called it a “well-done study that puts forward a compelling theory which is supported by their data.” While the tip of the spike is unique to the new coronavirus, the base is found in all coronaviruses, Dr. Kassiotis said. In lab tests, antibodies to the base of the spike prevented the new coronavirus from entering cells in order to reproduce. Stephen J. Elledge, a genetics professor at Harvard Medical School and Brigham and Women’s Hospital, had a similar response. He and others have found many people have antibodies to common colds caused by other coronaviruses; in laboratory studies, these antibodies also block the new coronavirus.- Advertisement –center_img In March, as the pandemic was just beginning, Dr. Kassiotis and his colleagues decided to develop a highly sensitive antibody test. To assess it, they examined blood samples taken before the pandemic from over 300 adults and 48 children and adolescents, comparing them with samples from more than 170 people who had been infected with the new coronavirus.The scientists expected samples taken before the pandemic to have no antibodies that attacked the new coronavirus. Those were to be the controls for the test the scientists were developing.Instead, they found that many children, and some adults, carried one antibody in particular that can prevent coronaviruses, including the new one, from entering cells. This antibody attaches itself to a spike that pokes out of coronaviruses.- Advertisement – “It is quite possible that you lose your memory over time,” Dr. Elledge said. He suspects that the new coronavirus may interfere with the activation of the memory cells able to respond to the infection.An infection “might give you a hazy memory that fades over time,” he said. If so, a very recent infection with a common cold coronavirus would be needed to protect against the new coronavirus, and even then the protection might last only for a limited time.The new coronavirus would have hobbled the production of antibodies that specifically attack it. That might explain why children, with their seemingly continuous colds, are much better off than adults.Dr. Elledge said that if he is right about the loss of memory cells, that bodes well for vaccines. A vaccine boosts antibody production without the presence of a virus. So the virus “is not in the background, messing up memory cell formation,” he said.Another possibility is that most adults actually are protected by memory cells from previous infections with the common cold. Although few have enough antibodies in their blood to protect them at any given time, they may be able to quickly make antibodies to lessen the impact of the new coronavirus.That might explain why many adults who are infected recover quickly.“We focus on those who get really sick, but 95 to 98 percent of those who get the virus don’t have to go to the hospital,” Dr. Elledge said. “There are a lot of people who do get better.” Antibody: A protein produced by the immune system that can recognize and attach precisely to specific kinds of viruses, bacteria, or other invaders.Antibody test/serology test: A test that detects antibodies specific to the coronavirus. Antibodies begin to appear in the blood about a week after the coronavirus has infected the body. Because antibodies take so long to develop, an antibody test can’t reliably diagnose an ongoing infection. But it can identify people who have been exposed to the coronavirus in the past.Antigen test: This test detects bits of coronavirus proteins called antigens. Antigen tests are fast, taking as little as five minutes, but are less accurate than tests that detect genetic material from the virus.Coronavirus: Any virus that belongs to the Orthocoronavirinae family of viruses. The coronavirus that causes Covid-19 is known as SARS-CoV-2. Covid-19: The disease caused by the new coronavirus. The name is short for coronavirus disease 2019.Isolation and quarantine: Isolation is the separation of people who know they are sick with a contagious disease from those who are not sick. Quarantine refers to restricting the movement of people who have been exposed to a virus.Nasopharyngeal swab: A long, flexible stick, tipped with a soft swab, that is inserted deep into the nose to get samples from the space where the nasal cavity meets the throat. Samples for coronavirus tests can also be collected with swabs that do not go as deep into the nose — sometimes called nasal swabs — or oral or throat swabs.Polymerase Chain Reaction (PCR): Scientists use PCR to make millions of copies of genetic material in a sample. Tests that use PCR enable researchers to detect the coronavirus even when it is scarce.Viral load: The amount of virus in a person’s body. In people infected by the coronavirus, the viral load may peak before they start to show symptoms, if symptoms appear at all. That happened to Dr. Larman and his family of five. Four of them got sick with Covid-19, the illness caused by the new coronavirus, in July. None were seriously ill, and his 4-year-old son was spared altogether.“My son was not isolated from us and therefore heavily exposed,” Dr. Larman said. “He tested negative twice, and so we certainly suspect that he had some form of pre-existing immunity.” It’s been a big puzzle of the pandemic: Why are children so much less likely than adults to become infected with the new coronavirus and, if infected, less likely to become ill?A possible reason may be that many children already have antibodies to other coronaviruses, according to researchers at the Francis Crick Institute in London. About one in five of the colds that plague children are caused by viruses in this family. Antibodies to those viruses may also block SARS-CoV-2, the new coronavirus causing the pandemic.- Advertisement –last_img read more

Pandemic drives broadest economic collapse in 150 years: World Bank

first_imgChina still growing, barely China is nearly alone in seeing modest growth this year. However the World Bank warned the depth of the slowdown in the world’s second-largest economy will hinder recovery prospects in developing nations, especially commodity exporters.While China will see GDP rise just one percent, the World Bank said, the rest of the forecasts are grim: US -6.1 percent, eurozone -9.1 percent, Japan -6.1 percent, Brazil -8 percent, Mexico -7.5 percent and India -3.2 percent.And things could get worse, meaning the forecasts will be revised even lower, the bank warned.Though dramatic, the current forecast falls short of the Great Depression, which saw a global contraction of 14.5 percent from 1930 to 1932, while the post-war downturn in 1945-1946 was 13.8 percent, according to the World Bank.But because of the pandemic there remain some “exceptionally high” risks to the outlook, particularly if the disease lingers and authorities have to reimpose restrictions — which could make the downturn as bad as eight percent.”Disruptions to activity would weaken businesses’ ability to remain in operation and service their debt,” the report cautioned.That, in turn, could raise interest rates for higher-risk borrowers. “With debt levels already at historic highs, this could lead to cascading defaults and financial crises across many economies,” it said. But even if the 4.2 percent global recovery projected for 2021 materializes, “in many countries, deep recessions triggered by COVID-19 will likely weigh on potential output for years to come.” The depth of the crisis will drive 70 to 100 million people into extreme poverty — worse than the prior estimate of 60 million, she told reporters.And while the Washington-based development lender projects a rebound for 2021, there is a risk a second wave of outbreaks could undermine the recovery and turn the economic crisis into a financial one that will see a “wave of defaults.”Economists have been struggling to measure the impact of the crisis they have likened to a global natural disaster, but the sheer size of the impact across so many sectors and countries has made that difficult.Under the worst-case scenario, the global recession could mean a contraction of eight percent, according to the report. The coronavirus pandemic inflicted a “swift and massive shock” that has caused the broadest collapse of the global economy since 1870 despite unprecedented government support, the World Bank said Monday.The world economy is expected to contract by 5.2 percent this year — the worst recession in 80 years — but the sheer number of countries suffering economic losses means the scale of the downturn is worse than any recession in 150 years, the World Bank said in its latest Global Economic Prospects report.”This is a deeply sobering outlook, with the crisis likely to leave long-lasting scars and pose major global challenges,” said World Bank Group Vice President for Equitable Growth, Finance and Institutions Ceyla Pazarbasioglu. But Pazarbasioglu cautioned: “Given this uncertainty, further downgrades to the outlook are very likely.”Meanwhile, a group of American economists who are the arbiters of when a recession starts and ends said Monday the United States entered a downturn in February, ending 128 months of uninterrupted growth, the longest streak in history.Recessions typically are defined by several months of declining economic activity.But the Business Cycle Dating Committee of the National Bureau of Economic Research (NBER), a non-profit, non-partisan research organization, called the current situation in the world’s largest economy “unprecedented” due to the severity of the drop in employment and production, even if it might turn out to be shorter than other recessions. Topics :last_img read more