Cell.
Scientists have long turned to llamas for antibody research. In the last decade, for example, scientists have used llamas’ antibodies in H.I.V. and influenza research, finding promising therapies for both viruses.
Humans produce only one kind of antibody, made of two types of protein chains — heavy and light — that together form a Y shape. Heavy-chain proteins span the entire Y, while light-chain proteins touch only the Y’s arms. Llamas, on the other hand, produce two types of antibodies. One of those antibodies is similar in size and constitution to human antibodies. But the other is much smaller; it’s only about 25 percent the size of human antibodies. The llama’s antibody still forms a Y, but its arms are much shorter because it doesn’t have any light-chain proteins.
This more diminutive antibody can access tinier pockets and crevices on spike proteins — the proteins that allow viruses like the novel coronavirus to break into host cells and infect us — that human antibodies cannot. That can make it more effective in neutralizing viruses.
Llamas’ antibodies are also easily manipulated, said Dr. Xavier Saelens, a molecular virologist at Ghent University in Belgium and an author of the new study. They can be linked or fused with other antibodies, including human antibodies, and remain stable despite those manipulations.
This antibody is a genetic characteristic llamas share with all camelids, the family of mammals that also includes alpacas, guanacos and dromedaries.
Sharks have these smaller antibodies, too, but they “are not a great experimental model, and are a lot less cuddly than llamas,” said Daniel Wrapp, a graduate student affiliated with the University of Texas at Austin and Dartmouth College, and a co-author of the new research. Dr. Saelens said that llamas are domesticated, easy to handle and less stubborn than many of their camelid cousins, although, “if they don’t like you, they’ll spit.”
In 2016, Dr. Saelens, Mr. Wrapp and Dr. Jason McLellan, a structural virologist at the University of Texas at Austin, and other researchers looked to llamas — and, specifically, Winter — to find a smaller llama antibody “that could broadly neutralize many different types of coronavirus,” Dr. McLellan said.
They injected Winter with spike proteins from the virus that caused the 2002-03 SARS epidemic as well as MERS, then tested a sample of her blood. And while they couldn’t isolate a single llama antibody that worked against both viruses, they found two potent antibodies that each fought separately against MERS and SARS.
The researchers were writing up their findings when the new coronavirus began to make headlines in January. They immediately realized that the smaller llama antibodies “that could neutralize SARS would very likely also recognize the Covid-19 virus,” Dr. Saelens said.
It did, the researchers found, effectively inhibiting the coronavirus in cell cultures.
The researchers are hopeful the antibody can eventually be used as a prophylactic treatment, by injecting someone who is not yet infected to protect them from the virus, such as a health care worker. While the treatment’s protection would be immediate, its effects wouldn’t be permanent, lasting only a month or two without additional injections.
This proactive approach is at least several months away, but the researchers are moving toward clinical trials. Additional studies may also be needed to verify the safety of injecting a llama’s antibodies into human patients.
“There is still a lot of work to do to try to bring this into the clinic,” Dr. Saelens said. “If it works, llama Winter deserves a statue.”
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Updated April 11, 2020
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What should I do if I feel sick?
If you’ve been exposed to the coronavirus or think you have, and have a fever or symptoms like a cough or difficulty breathing, call a doctor. They should give you advice on whether you should be tested, how to get tested, and how to seek medical treatment without potentially infecting or exposing others.
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When will this end?
This is a difficult question, because a lot depends on how well the virus is contained. A better question might be: “How will we know when to reopen the country?” In an American Enterprise Institute report, Scott Gottlieb, Caitlin Rivers, Mark B. McClellan, Lauren Silvis and Crystal Watson staked out four goal posts for recovery: Hospitals in the state must be able to safely treat all patients requiring hospitalization, without resorting to crisis standards of care; the state needs to be able to at least test everyone who has symptoms; the state is able to conduct monitoring of confirmed cases and contacts; and there must be a sustained reduction in cases for at least 14 days.
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How can I help?
The Times Neediest Cases Fund has started a special campaign to help those who have been affected, which accepts donations here. Charity Navigator, which evaluates charities using a numbers-based system, has a running list of nonprofits working in communities affected by the outbreak. You can give blood through the American Red Cross, and World Central Kitchen has stepped in to distribute meals in major cities. More than 30,000 coronavirus-related GoFundMe fund-raisers have started in the past few weeks. (The sheer number of fund-raisers means more of them are likely to fail to meet their goal, though.)
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Should I wear a mask?
The C.D.C. has recommended that all Americans wear cloth masks if they go out in public. This is a shift in federal guidance reflecting new concerns that the coronavirus is being spread by infected people who have no symptoms. Until now, the C.D.C., like the W.H.O., has advised that ordinary people don’t need to wear masks unless they are sick and coughing. Part of the reason was to preserve medical-grade masks for health care workers who desperately need them at a time when they are in continuously short supply. Masks don’t replace hand washing and social distancing.
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How do I get tested?
If you’re sick and you think you’ve been exposed to the new coronavirus, the C.D.C. recommends that you call your healthcare provider and explain your symptoms and fears. They will decide if you need to be tested. Keep in mind that there’s a chance — because of a lack of testing kits or because you’re asymptomatic, for instance — you won’t be able to get tested.
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How does coronavirus spread?
It seems to spread very easily from person to person, especially in homes, hospitals and other confined spaces. The pathogen can be carried on tiny respiratory droplets that fall as they are coughed or sneezed out. It may also be transmitted when we touch a contaminated surface and then touch our face.
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What makes this outbreak so different?
Unlike the flu, there is no known treatment or vaccine, and little is known about this particular virus so far. It seems to be more lethal than the flu, but the numbers are still uncertain. And it hits the elderly and those with underlying conditions — not just those with respiratory diseases — particularly hard.
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What if somebody in my family gets sick?
If the family member doesn’t need hospitalization and can be cared for at home, you should help him or her with basic needs and monitor the symptoms, while also keeping as much distance as possible, according to guidelines issued by the C.D.C. If there’s space, the sick family member should stay in a separate room and use a separate bathroom. If masks are available, both the sick person and the caregiver should wear them when the caregiver enters the room. Make sure not to share any dishes or other household items and to regularly clean surfaces like counters, doorknobs, toilets and tables. Don’t forget to wash your hands frequently.
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Can I go to the park?
Yes, but make sure you keep six feet of distance between you and people who don’t live in your home. Even if you just hang out in a park, rather than go for a jog or a walk, getting some fresh air, and hopefully sunshine, is a good idea.
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Should I pull my money from the markets?
That’s not a good idea. Even if you’re retired, having a balanced portfolio of stocks and bonds so that your money keeps up with inflation, or even grows, makes sense. But retirees may want to think about having enough cash set aside for a year’s worth of living expenses and big payments needed over the next five years.
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