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First documented coronavirus reinfection reported in Hong Kong

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A 33-year-old man was infected a second time with the coronavirus more than four months after his first bout, the first documented case of so-called reinfection, researchers in Hong Kong reported Monday.

The finding was not unexpected, especially given the millions of people who have been infected worldwide, experts said. And the man had no symptoms the second time, suggesting that even though the prior exposure did not prevent the reinfection, his immune system kept the virus somewhat in check.

“The second infection was completely asymptomatic — his immune response prevented the disease from getting worse,” said Akiko Iwasaki, an immunologist at Yale University who was not involved with the work but reviewed the report at The New York Times’ request. “It’s kind of a textbook example of how immunity should work.”

People who do not have symptoms may still spread the virus to others, however, underscoring the importance of vaccines, Iwasaki said. In the man’s case, she added, “natural infection created immunity that prevented disease but not reinfection.”

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“In order to provide herd immunity, a potent vaccine is needed to induce immunity that prevents both reinfection and disease,” Iwasaki said.

Doctors have reported several cases of presumed reinfection in the United States and elsewhere, but none of those cases have been confirmed with rigorous testing. Recovered people are known to carry viral fragments for weeks, which can lead to positive test results in the absence of live virus.

But the Hong Kong researchers sequenced the virus from both of the man’s infections and found significant differences, suggesting that the patient had been infected a second time.

“I believe this is the first reported case that is confirmed by genome sequencing,” said Dr. Kelvin Kai-Wang To, a clinical microbiologist at the University of Hong Kong.

The study is to be published in the journal Clinical Infectious Diseases. The Times obtained the manuscript from the university.

The man’s first case was diagnosed March 26, and he had only mild symptoms. In accordance with regulations in Hong Kong, he was hospitalized March 29 even though his symptoms had subsided and released April 14 only after he had tested negative for the virus twice.

He had no detectable antibodies after that first bout with the virus. He was positive again for the coronavirus on a saliva test Aug. 15 after a trip to Spain via the United Kingdom; the test was administered at the airport. The man had picked up a strain that was circulating in Europe in July and August, the researchers said.

His infections were clearly caused by different versions of the coronavirus, To said. “Our results prove that his second infection is caused by a new virus that he acquired recently, rather than prolonged viral shedding.”

Common cold coronaviruses are known to cause reinfections in less than a year, but experts had hoped that the new coronavirus might behave more like its cousins, severe acute respiratory syndrome and Middle East respiratory syndrome, which seemed to produce protection lasting a few years.

It is still unclear how common reinfection from the new coronavirus might be because few researchers have sequenced the virus from each infection.

“We’ve had, what, 23 million cases documented thus far, but the fact that one out of them at this point has been reinfected should not cause undue alarm as of yet,” said Jeffrey Shaman, an epidemiologist at Columbia University in New York.

“However, it remains very, very concerning — and this does nothing to dispel that — that we may be subject to repeat infection with this virus,” he said.

Iwasaki was more sanguine. She noted that the man had no antibodies after the first infection but produced them after the second exposure. Immunity is expected to build with each exposure to a pathogen exactly in this way, she noted.

“Again, it’s what the textbook says should happen,” she said. “When you have second exposure to the same pathogen, you should elevate the antibody, and that’s what’s happening.”

Most people who are infected with the coronavirus produce detectable antibodies that would be expected to protect against the virus. Even people who had only mild symptoms, including this man, may also have immune “memory” in the form of B and T cells that prevent symptoms on second exposure.

“The majority of patients likely have a cocktail of immune responses that activate on second exposure,” said Brian Wasik, a virologist at Cornell University. “This Hong Kong patient also seems to have been asymptomatic on second infection, perhaps due to some immune response.”

But the researchers said it’s also possible that in some people, a second exposure will prove more severe. “It cannot be generalized yet, because there’s still a possibility that the second infection can be worse,” To said.

Building immune memory is not unlike boosting memory of a person, said Dr. Michael Mina, an immunologist at the Harvard T.H. Chan School of Public Health.

The initial bout with the new coronavirus is likely to result in “nonsterilizing immunity,” but the virus will elicit a stronger response with each exposure, he said: “It is often these second and third exposures that help to solidify the memory response for the long term.”

Overall, experts said, it is unclear how often people might become reinfected, and how soon, after a first bout with the virus.

“Those remain open questions, because one person exhibiting a mild reinfection, clearly documented as a distinct strain of the virus, does not provide enough evidence one way or another,” Shaman said.

Source: – The Japan Times

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It's possible to rely on plant proteins without sacrificing training gains, new studies say – The Globe and Mail

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At the 1936 Olympics in Berlin, a scientist named Paul Schenk surveyed the eating habits of top athletes from around the world. The Canadians reported plowing through more than 800 grams of meat per day on average; the Americans were downing more than two litres of milk daily.

While there have been plenty of changes in sports nutrition since then, the belief that meat and dairy are the best fuel for building muscle persists. These days, though, a growing number of athletes are interested in reducing or eliminating their reliance on animal proteins, for environmental, ethical or health reasons. A pair of new studies bolsters the case that it’s possible to rely on plant proteins without sacrificing training gains, as long as you pick your proteins carefully.

The standard objection to plant proteins is that they don’t have the right mix of essential amino acids needed to assemble new muscle fibres. Unlike animal proteins, most plant proteins are missing or low in at least one essential amino acid.

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In particular, there’s one specific amino acid, leucine, that seems to play a special role in triggering the synthesis of new muscle. It’s particularly abundant in whey, one of the two proteins (along with casein) found in milk. That’s why whey protein is the powdered beverage of choice in gyms around the world, backed by decades of convincing research, which was often funded by the dairy industry.

But one of the reasons whey looks so good may be that we haven’t fully explored the alternatives. A 2018 study by Luc van Loon of the University of Maastricht in the Netherlands, for example, tested nine vegetable proteins including wheat, hemp, soy, brown rice, pea and corn. To their surprise, they found that corn protein contains 13.5 per cent leucine – even more than whey.

Based on that insight, van Loon decided to pit corn against milk in a direct test of muscle protein synthesis. Volunteers consumed 30 grams of one of the proteins; a series of blood tests and muscle biopsies were collected over the next five hours to determine how much of the ingested protein was being turned into new muscle fibres. The results, which appeared in the journal Amino Acids, were straightforward: Despite all the hype about whey, there was no discernible difference between them.

A second study, this one published in Medicine & Science in Sports & Exercise by a team led by Benjamin Wall of the University of Exeter in Britain, had similar findings. Instead of corn, it used a mix of 40 per cent pea, 40 per cent brown rice and 20 per cent canola proteins. Since different plants have different amino acids profiles, mixing complementary proteins has long been suggested as a way overcoming the deficiencies of any single plant protein. Sure enough, the protein blend triggered just as much new muscle synthesis as whey.

On the surface, the message from these studies is straightforward: Plant proteins are – or at least can be – as effective as even the best animal proteins for supporting muscle growth. There are a few caveats to consider, though. One is that the studies used isolated protein powders rather than whole foods. You would need nearly nine cobs of corn to get the 30 grams of protein used in van Loon’s study, compared to just three-and-a-half cups of milk.

Another is that plants are generally harder to digest, meaning that not all the amino acids will be usable. That may not be a problem for healthy young adults consuming 30 grams of protein at once, which is enough to trigger a near-maximal muscle response. But for older people, who tend to have blunted muscle-building responses to protein, or in situations where you’re getting a smaller dose of protein, the details of protein quality may become more important.

Of course, the effectiveness of plant proteins won’t be news to notable plant-based athletes such as ultrarunner Scott Jurek or basketball star Chris Paul – but it’s encouraging to see the science finally begin to catch up.

Alex Hutchinson is the author of Endure: Mind, Body, and the Curiously Elastic Limits of Human Performance. Follow him on Threads @sweat_science.

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See how chicken farmers are trying to stop the spread of bird flu – Fox 46 Charlotte

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CLOVER, S.C. (QUEEN CITY NEWS) — Poultry farmers across the Carolinas aren’t taking any chances.  Many are turning to strict protocols as another wave of bird flu continues to threaten the chicken population across the country. 

Since 2022, it is estimated more than 90 million birds have either died from the virus or were killed to prevent further spread in the U.S. 

“We try to make them the happiest as possible. We always say a happy chicken is a tasty chicken,” owner of Eden Farms Adam Shumate said. 

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With their happiness in mid, Shumate also wants to keep his chickens alive and healthy. On his farm in Clover, he has implemented protocols to minimize a potential bird flu outbreak.  

“We want to be prepared,” he said. “We feel like the things that we can do to prevent it first is the best case because we don’t want to start from scratch with a whole new flock.”  

Because bird flu is commonly spread through bird droppings, Shumate is limiting the number of people coming into contact with his flocks. He says this would minimize the chances of someone walking onto the property with bird droppings on the bottoms of their shoes. 

On top of monitoring the chickens closely, Shumate and his staff are constantly cleaning their equipment, including what they wear on their feet.   

“We have specific shoes that are just for working with the flock and for when we are taking care of them,” Shumate said. 

Other farmers, like Holly Burrell, haven’t let a visitor step foot near her hens in Gastonia for more than two years. 

No visitors or outside cars are welcomed, and her chickens are separated in what she calls “tent cities.” 

“We don’t want to do that because we want them to live their best life,” Burrell said in a 2022 interview with Queen City News. 

Recently, health officials have detected bird flu in other animals like seals, squirrels and dolphins. 

Earlier this month, bird flu was detected in one of the state’s dairy cow herds. While concerning, state health officials say the overall risk to the general public remains low. 

“I’ve not heard of any cases, zero cases of people being affected by this virus associated with food consumption, milk consumption with egg consumption… any of these products we’re getting from farm animals is not really been associated with any human risk at this point,” said Dr. Michael Martin, director of the Veterinary Division at the N.C. Department of Agriculture and Consumer Services. 

As of March 28, at least 80 birds in North Carolina were detected with the virus. Back in York County, Shumate says it all starts with the individual farms. 

“When it comes to wildlife and things that that, there is only so much that you can do is be observant,” Shumate said. “Keep a healthy flock that way they can find off the infections that may come about.” 

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CFIA Monitoring for Avian Influenza in Canadian Dairy Cattle After US Discoveries – Morning Ag Clips –

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From the field to your inbox, the Weekend Edition of the Morning Ag Clips features stories, trends, and unique perspectives from the farming community. This laid-back edition is great for anyone looking for a fun weekend read.

Morning Ag Clips. All ag. All the time.

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