Eight months ago, the new coronavirus was unknown. But to some of our immune cells, the virus was already something of a familiar foe.A flurry of recent studies has revealed that a large proportion of the population -- 20% to 50% of people in some places -- might harbor immunity assassins called T cells that recognize the new coronavirus despite having never encountered it before.These T cells, which lurked in the bloodstreams of people long before the pandemic began, are most likely stragglers from past scuffles with other, related coronaviruses, including four that frequently cause common colds. It's a case of family resemblance: In the eyes of the immune system, germs with common roots can look alike, such that when a cousin comes to call, the body may already have an inkling of its intentions.The presence of these T cells has intrigued experts, who said it was too soon to tell whether the cells would play a helpful, harmful or entirely negligible role in the world's fight against the current coronavirus. But should these so-called cross-reactive T cells exert even a modest influence on the body's immune response to the new coronavirus, they might make the disease milder -- and perhaps partly explain why some people who catch the germ become very sick, while others are dealt only a glancing blow."If you have a population of T cells that are armed and ready to protect you, you could control the infection better than someone who doesn't have those cross-reactive cells," said Marion Pepper, an immunologist at the University of Washington who is studying the immune responses of COVID-19 patients. "That's what we're all hoping for."T cells are an exceptionally picky bunch. Each spends the entirety of its life waiting for a very specific trigger, like a hunk of a dangerous virus. Once that switch is flipped, the T cell will clone itself into an army of specialized soldiers, all with their sights set on the same target. Some T cells are microscopic assassins, tailor-made to home in on and destroy infected cells; others coax immune cells called B cells into producing virus-attacking antibodies.The first time a virus infects the body, this response is sluggish; it takes several days for the immune system to sort out which T cells are best suited for the job at hand. But subsequent encounters typically prompt a response that is stronger and faster, thanks to a reserve force of T cells, called memory T cells, that lingers after the initial threat has passed and can quickly be called into action again.Usually, this process operates best when T cells must battle the same pathogen again and again. But these recruits are more flexible than they are often given credit for, said Laura Su, an immunologist and T cell expert at the University of Pennsylvania. Should these cells chance upon something that bears a strong resemblance to their germ of choice, they can still be roused to fight, even if the invader is a total newcomer.In theory, cross-reactive T cells can "protect almost like a vaccine," said Smita Iyer, an immunologist at the University of California, Davis, who is studying immune responses to the new coronavirus in primates. Previous studies have shown that cross-reactive T cells may guard people against different strains of the flu virus, and perhaps confer a trace of immunity against dengue and Zika viruses, which share a family tree.The case for coronaviruses is less clear cut, said Alessandro Sette, an immunologist at the La Jolla Institute for Immunology who has led several studies examining cross-reactive T cells to the new coronavirus. Researchers have found people in the United States, Germany, the Netherlands, Singapore and the United Kingdom who have never been exposed to the new coronavirus but who carry T cells that react to it in the lab.Researchers are eager to understand the history of these T cells, because that might help reveal who is more likely to have them. A growing body of evidence, including data published this week in Science by Sette and his colleagues, points to common-cold coronaviruses as a potential source. But even unrelated viruses can share similar features, and researchers may never know for sure what originally "drove their development," said Avery August, an immunologist and T cell expert at Cornell University.Whatever the origin of T cells, their mere existence could be encouraging news. There is much more to the immune system than T cells, but even a semblance of preexisting immunity could mean that people who have recently grappled with the common cold may have an easier time fighting off a nastier member of the coronavirus clan.Cross-reactive T cells alone probably would not be enough to completely stave off infection or disease. But they might alleviate symptoms of the coronavirus in people who happen to carry these cells, or extend the protection provided by a vaccine."That would be awesome," Iyer said.Children, who share lots of germs with their peers, might be good candidates for this hypothetical scenario.But cross-reactive T cells are not necessarily a benevolent force. They could instead be ineffectual souvenirs of infections past, with "absolutely no relevance" to how well people fare against the new coronavirus, Sette said.There is even a small chance that preexisting T cells could raise the risk for serious symptoms of COVID-19, although experts consider this possibility unlikely. T cells that are primed to recognize common-cold coronaviruses might marshal only a lackluster response to the current coronavirus, potentially sapping resources from other populations of immune cells that have a better shot at defeating the new invader. "Now you have your immune system distracted," Iyer said.T cells are also expert orchestrators. Depending on the signals they send out, they can synchronize cells and molecules from disparate parts of the immune system into a tag-teamed attack, or quell these assaults to return the body to baseline. If it turns out that cross-reactive T cells tend toward quieting the response, they could suppress a person's immune defense before it has a chance to kick into gear, August said.Then again, many types of T cells exist, and all operate as part of a complex immune system. "It's almost like some people are trying to say this is 'good' or 'bad,'" Su said. "It's probably more nuanced than that."Teasing it all apart will not be easy. Unlike antibodies, which are inanimate proteins that often circulate in the blood, T cells are living cells that often hole up in hard-to-reach tissues. That makes them much more difficult to extract, maintain and analyze, Pepper said.Researchers could learn more by testing whether cross-reactive T cells are more abundant in patients who have had mild or serious cases of COVID-19, although such studies cannot prove cause and effect. A more laborious effort might involve measuring cross-reactive T cell levels in large groups of healthy people, then waiting to see if they became infected or sick from the current coronavirus, Sette said.Strong evidence could also come from an animal model, like the rhesus macaques that Iyer studies in her lab. Researchers could dose primates with common-cold coronaviruses, and then see how their immune responses stack up against the new coronavirus.Less than a year into this pandemic, plenty of questions remain unanswered, Pepper said. Immunologists cannot fully forecast how the human immune system will respond to this new virus; even with science at its speediest, that interaction must be studied in real time.It's a frustrating reality, Pepper said: "Until we see it in real life, we just don't know."This article originally appeared in The New York Times.(C) 2020 The New York Times Company
The Food and Drug Administration's list of hand sanitizers to avoid has more than 130 varieties, most on the list because they may contain methanol.
For a spiky sphere just 120 nanometers wide, the coronavirus can be a remarkably cosmopolitan traveler.Spewed from the nose or mouth, it can rocket across a room and splatter onto surfaces; it can waft into poorly ventilated spaces and linger in the air for hours. At its most intrepid, the virus can spread from a single individual to dozens of others, perhaps even a hundred or more at once, proliferating through packed crowds in what is called a superspreading event.Such scenarios, which have been traced to call centers, meat processing facilities, weddings and more, have helped propel a pandemic that, in the span of eight months, has reached nearly every corner of the globe. And yet, while some people seem particularly apt to spread the coronavirus, others barely pass it on."There's this small percentage of people who appear to infect a lot of people," said Dr. Joshua Schiffer, a physician and mathematical modeling expert who studies infectious diseases at the Fred Hutchinson Cancer Research Center in Seattle. Estimates vary from population to population, but they consistently show a striking skew: Between 10% and 20% of coronavirus cases may seed 80% of new infections. Other respiratory diseases, like the flu, are far more egalitarian in their spread.Figuring out what drives coronavirus superspreading events could be key to stopping them, and expediting an end to the pandemic. "That's the million dollar question," said Ayesha Mahmud, who studies infectious disease dynamics at the University of California, Berkeley.In a paper posted Friday to the website medRxiv that has not yet been through peer review, Schiffer and his colleagues reported that coronavirus superspreading events were most likely to happen at the intersection where bad timing and poor placement collide: a person who has reached the point in their infection when they are shedding large amounts of virus, and are doing so in a setting where there are plenty of other people around to catch it.According to a model built by Schiffer's team, the riskiest window for such transmission may be extremely brief -- a one- to two-day period in the week or so after a person is infected, when coronavirus levels are at their highest.The virus can still spread outside this window, and individuals outside it should not let up on measures like mask-wearing and physical distancing, Schiffer said. But the longer an infection drags on, the less likely a person is to be contagious -- an idea that might help experts advise when to end self-isolation, or how to allocate resources to those most in need, said Mahmud, who was not involved in the study.Catching and containing a person at their most infectious is another matter, however. Some people stricken with the coronavirus start to feel unwell within a couple days, whereas others take weeks, and many never end up experiencing symptoms. The length of the so-called incubation period, which spans the time between infection and the onset of symptoms, can be so variable that some people who catch the virus fall ill before the person who gave it to them does. That rarely happens with the flu, which reliably rouses a spate of symptoms within a couple days of infection.If the coronavirus reaches a peak in the body before symptoms appear -- if symptoms appear at all -- that increase might be very tough to identify without frequent and proactive testing. Symptom-free spikes in virus load appear to happen very often, which "really distorts our ability to tell when somebody is contagious," Schiffer said. That, in turn, makes it all too easy for people to obliviously shed the pathogen."It really is about opportunity," said Shweta Bansal, an infectious disease ecologist at Georgetown University who was not involved in the study. "These processes really come together when you are not only infected, but you also don't know you're infected because you don't feel crummy." Some of these unwitting coronavirus chauffeurs, emboldened to go out in public, may end up causing a superspreading event that sends the pathogen blazing through a new population.This confluence of factors -- a person in the wrong place at the wrong point in their infection -- sets the stage for "explosive transmission," Bansal said.The team's model also pointed to another important variable: the remarkable resilience of the coronavirus when it is aloft.A growing body of evidence now suggests that the coronavirus can be airborne in crowded, poorly ventilated indoor environments, where it may encounter many people at once. The virus also travels in larger, heavier droplets, but these quickly fall to the ground after they are expelled from the airway and do not have the same reach or longevity as their smaller counterparts. Schiffer said he thought the coronavirus might be more amenable to superspreading than flu viruses because it is better at persisting in contagious clouds, which can ferry pathogens over relatively long distances."It's a spatial phenomenon," he said. "People further away from the transmitter may be more likely to be infected."Since the start of the pandemic, many comparisons have been drawn between COVID-19 and the flu, both of which are diseases caused by viruses that attack the respiratory tract. But plenty of differences exist, and in many ways the coronavirus is more formidable."This study adds yet another layer to how it's different from influenza," said Olivia Prosper, a researcher at the University of Tennessee who uses mathematical models to study infectious diseases but was not involved in the study. "It's not just about how sick it makes you, but also its ability to transmit."Moreover, certain people may be predisposed to be more generous transmitters of the coronavirus, although the details are "still a mystery," Schiffer said.But when a superspreading event occurs, it likely has more to do with the circumstances than with a single person's biology, Schiffer said. Even someone carrying a lot of the coronavirus can stave off mass transmission by avoiding large groups, thus depriving the germ of conduits to travel."A superspreading event is a function of what somebody's viral load is and if they're in a crowded space," he said. "If those are the two levers, you can control the crowding bit."Both Mahmud and Prosper noted that not everyone has the means to practice physical distancing. Some people work essential jobs in packed environments, for instance, and are left more vulnerable to the consequences of superspreading events.That makes it all the more important for those who can participate in control measures like mask-wearing and physical distancing to remain vigilant about their behavior, Mahmud said."That's what we should be doing," she said. "Not just to protect ourselves, but to protect others."This article originally appeared in The New York Times.(C) 2020 The New York Times Company
Multisystem inflammatory syndrome (MIS-C) is a rare but severe condition that shares symptoms with toxic shock and Kawasaki disease, including fever, rashes, swollen glands and, in severe cases, heart inflammation. It has been reported in children and adolescent patients about two to four weeks after the onset of COVID-19. With rising COVID-19 cases, there could be an increased occurrence of MIS-C, but this might not be apparent immediately because of the delay in development of symptoms, said the report's authors, including those from the CDC's COVID-19 response team.
Offenders with mental health conditions at a southern German hospital can pitch in with looking after a small herd of alpacas as part of their therapy. Staff at the Mainkofen psychiatric hospital in Bavaria say the aim is for the generally calm animals to help patients develop skills towards social reintegration. Erwin Meier, whose name has been changed for this report, has helped care for the alpacas since October and believes it has helped him.
Eating disorders are rife in the fitness industry and abs often come at the cost of mental health, PTs Hayley Madigan and Ben Carpenter told Insider.
The coronavirus may be changing the world, but there aren't many signs of the pandemic at the massive annual motorcycle rally being held this week at a small city along Interstate 90 in western South Dakota. The scene Saturday at the 80th Sturgis Motorcycle Rally was familiar to veterans of the event, with throngs of maskless bikers packing the streets. Motorcyclist Kevin Lunsmann, 63, rode more than 600 miles (965 kilometers) to the rally from Big Lake, Minnesota, with several friends.
Facing a new surge of coronavirus infections, one Spanish town is deploying special police units to nightclubs to enforce health regulations to stop the virus from spreading. The small beach town of Fuengirola near Málaga on Spain’s southern coast has sent police to its nightclubs — which are a magnet for young people seeking summer fun — to keep them from becoming virus breeding grounds. “The police pressure that is carried out is essential so that people who are resistant to the law end up complying with it,” police officer Jorge Moreno told The Associated Press, adding that since June 15, police have issued 2,000 sanctions for not complying with health regulations.
Brazil was leaping toward a grim milestone of 100,000 deaths from COVID-19 on Saturday, and five months after the first reported case the country has not shown signs of crushing the disease. The Health Ministry said there had been a total of 2,962,442 confirmed infections with the new coronavirus — death and infection tolls second only to the United States. In a tribute to COVID-19 victims, the non-governmental group Rio de Paz placed crosses on the sand on the famed Copacabana beach Saturday and released 1,000 red balloons into the sky.
The federal government has allocated more than $9 billion among 7 companies to develop, make COVID-19 vaccine.
Peer support networks and online therapy are just two of the ways that those feeling anxious or depressed can reach out for support.
Golfing and picnicking aren't as risky as dining indoors or at a bar. Here's how your daily summer activities stack up in terms of coronavirus risk.
SAINT-TROPEZ, France (AP) — The glamorous French Riviera resort of Saint-Tropez began requiring face masks outdoors Saturday, threatening to sober the mood in a place renowned for high-end, free-wheeling summer beach parties. More French cities and towns, especially in tourist areas, are imposing mask requirements as the country's coronavirus infections creep up again. The uptick corresponds with France’s beloved summer holidays, when vacationers head off in droves, often to the seashore, for festive gatherings with family and friends.
Almost half (41%) of them said they quit as a direct response to heightened health concerns during the coronavirus pandemic.
President Donald Trump has signed executive orders bypassing Congress to defer payroll taxes for some Americans and extend unemployment benefits after negotiations on a new coronavirus rescue package collapsed. Trump accused Democrats of loading up their rescue bill with priorities unrelated to the coronavirus. Trump said the payroll tax cut would apply to those earning less than $100,000 a year.
Unequal access to coronavirus tests in the Latino community does not surprise experts calling the gaps a factor in disproportionate cases and deaths.
The Australian state of Victoria recorded 466 new cases of COVID-19 and 12 deaths, including another man in his 30s. The figures were released as the city of Melbourne remained in lockdown and under an overnight curfew. Victoria Premier Daniel Andrews said that six of the deaths were connected to outbreaks at aged care facilities.
Gates predicts that the world's richest nations will get the virus under control by end of next year while the world as a whole could need until 2022.
La falta de pruebas en las comunidades latinas no sorprende a los expertos que creen que la disparidad es un factor en los casos y fallecimientos.
Thousands of bikers poured into the small South Dakota city of Sturgis on Friday as the 80th Sturgis Motorcycle Rally rumbled to life despite fears it could lead to a massive coronavirus outbreak. The rally could become one of the largest public gatherings since the pandemic began, with organizers expecting 250,000 people from all over the country to make their way through Sturgis during the 10-day event.
Racial disparities in the U.S. coronavirus epidemic extend to children, according to two sobering government reports released Friday. One of the Centers for Disease Control and Prevention reports looked at children with COVID-19 who needed hospitalization. Hispanic children were hospitalized at a rate eight times higher than white kids, and Black children were hospitalized at a rate five times higher, it found.
Not all tests work the same way, nor do they always provide identical results. Even the same test — taken twice — can show contradictory outcomes.
Lawsuits filed by two Ohio counties against retail pharmacy chains claiming their opioid dispensing practices flooded communities with pain pills and were a a public nuisance can continue, a federal judge in Cleveland has determined. U.S. District Judge Dan Polster rejected the pharmacy chains' motion to dismiss the suits, ruling Thursday that the Ohio law does indeed apply to Lake and Trumbull counties' nuisance claims.
“He’s not a radical. But he is running on the most liberal policy platform of any Democratic candidate in modern history.”
“Public opinion has been shifting leftward, and Biden’s thinking has shifted with it.”
“Biden shows that he’s more moderate than some in his party.”
“Biden has always been a creature of his time, and the COVID-19 crisis could force him to veer further left.”
“Liberal activists have lauded the campaign’s outreach to progressives.”