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

L.A. Dodgers’ Chris Hatcher now rolling along in fine fashion

first_img• Photos: Arizona Diamondbacks defeat the Los Angeles Dodgers 8-0 MLBHatcher has self-analyzed a lot, saying “I’ve covered it 50 times since I’ve been back.”Manager Don Mattingly, while discussing Hatcher late last week, said that Hatcher has “kind of pushed himself into that spot,” meaning set-up man. But Hatcher isn’t taking a thing for granted.“No, bullpens are a thing that you kind of take the hot hand at the time, and I guess you could say I’ve got a hot hand right now,” Hatcher said Tuesday before the Dodgers took on the Arizona Diamondbacks. “But that could change in one day, so I don’t think there is any established thing in a bullpen, so to speak, unless you’re a closer.“So you just keep fighting and keep working to maintain where you’re at and get better.” Hatcher, 30, most recently appeared in Saturday’s 3-2 loss to Pittsburgh. He gave up an RBI double to Aramis Ramirez in the eighth inning that proved to be the winning run. The run was charged to Clayton Kershaw, however, as Kershaw had given up a leadoff double to Gregory Polanco.Still, as recent times go, it was a rare failing for Hatcher.Hatcher did a rehab stint at Oklahoma City before being reactivated. He only pitched 4 1/3 innings there, with an ERA of 8.31. But he was there with a purpose, Mattingly said at the time.“He’s going to be pitching in Oklahoma and continuing to pitch different-type settings, from one (inning) plus, to back-to-back (games), just trying to … put a lot of different things on his plate so he fits back in with our club,” he said Aug. 9. “… Now it’s just a matter of him sequencing, pitching, getting sharp.” Mission accomplished.Turner updateThird baseman Justin Turner has not played since coming out of Saturday’s game with left knee soreness. An MRI on Monday revealed a bone bruise and inflamed tendon.Mattingly sounded optimistic about a quick return.“We see him out here today,” Mattingly said during infield drills. “He hit a little bit in the cage, did his warmups, going to take some ground balls. So, obviously, he’s feeling better and we’ll see how this day affects him and how we make decisions going forward.”Rollins close to returningShortstop Jimmy Rollins has not played in the field since Sept. 6 because of an injured index finger on his throwing hand. Mattingly expects Rollins back at his position any day now.“You see him working again today, and I’m hoping Jimmy is available in the next couple of days,” Mattingly said.Rollins had been used as a pinch-hitter the past three games.Liberatore recalledThe Dodgers on Tuesday recalled southpaw reliever Adam Liberatore, who last pitched in a postseason game for Triple-A Oklahoma City on Sept. 11.Mattingly said that even though he has plenty of arms in the bullpen with the expanded roster, he wanted Liberatore because Jim Johnson and his wife are expecting a baby any day and Johnson figures to be gone for a few days.Liberatore is 2-2 with an ERA of 4.15 in 35 games for the Dodgers this season. He went 0-1 with three saves and an ERA of 3.74 in 19 games at Triple-A. When Chris Hatcher went on the disabled list in mid-June with a left oblique strain, the Dodgers relief pitcher had an ERA of 6.38 with two saves, seven holds and two blown saves.He was activated in mid-August, and going into Tuesday’s game had an ERA of 1.25 in 16 innings since then to reduce his ERA to a respectable 3.93. The set-up man now has three saves and 11 holds.To Hatcher, not much has changed in the way he has gone about his business, the much-improved numbers notwithstanding.“No,” he said, when asked if he has made any changes. “Making better pitches, getting a little better luck and things are going my way.”center_img Newsroom GuidelinesNews TipsContact UsReport an Errorlast_img read more