The first case of repeated Covid-19 infection is bad news

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Megan Molteni Gregory Barber

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Throughout the Covid-19 pandemic, scientists have stated that if the new coronavirus, SARS-CoV-2, persists long enough, it is possible for others to get it more than once. This is based on what immunologists know about other members of the coronavirus circle of relatives, those who have long survived initial overflow occasions and now circulate seasonally, causing colds. People who have poor health expand an immune reaction that protects them for months or years, depending on the person. But at some point, this coverage decreases and they become vulnerable to infection again.

On Monday, researchers at the University of Hong Kong presented the first confirmation that this may, in fact, be with SARS-CoV-2. It’s no surprise, experts say. But it remains a useful point of knowledge for how coronavirus immunity works, both in Americans and in populations. At the molecular point of antibodies and T cells, the case provides an explanation of why hope. As for the chances of obtaining collective immunity without a vaccine? This is an example warning.

The report mainly points out how in March a 33-year-old boy living in Hong Kong suffered a sore throat, cough, fever and headache. Tests showed it was positive for the virus. After two weeks in the hospital, his symptoms subsided and he was discharged. He’s been brought back to life. And during the summer, he went to Spain. In August, on the way home, he rubbed himself at Hong Kong Airport as part of the strict passenger detection procedure designed to stumble upon any re-importation of the virus. He had no fever or cough, no symptoms. But the check was positive again.

When university of Hong Kong scientists compared the viral genomes extracted from each swab, they discovered significant differences between them. Both were SARS-CoV-2, but their genetic fingerprints did not match. The virus that inflamed humans in The March High is very similar to the strains collected in the United States and England in the spring. It was discovered that its internal structure at the peak of August resembled the strains circulating in Europe at the end of the summer. The only credible explanation, the investigators concluded, is that four and a half months after their first fight with Covid-19, had swelled for a moment.

Does it look bad? Course.But for those who examine the immune formula, a case of reinfection is not necessarily the same as a lack of protection.”It’s good news that this user is protected from the disease,” says Donna Farber, an immunologist at Columbia University.It is not unusual for respiratory viruses to infect other people more than once, and Farber was not surprised to see that it was happening with SARS-CoV-2.All of this is a component of the herbal procedure to strengthen immunity over time, such as receiving a booster injection after vaccination.But the important thing, he says, is that at the moment when, the immune formula turns out to have fulfilled its task and eliminated the virus without much drama.It’s immunity at work.” Normally, this wouldn’t even be recorded, because this guy didn’t get sick.You wouldn’t even see it,” he says.

However, it is difficult to extrapolate from a singles case.Scientists did not know what to do with this world premiere, in part because of the way the data was disseminated.The effects of the study were first published in a press release from the University of Hong Kong on Monday, and then in an article in the South China Morning Post, WIRED received a copy of the manuscript, which was later published online in clinical Infectious Diseases.Yuen Kwok-yung, one of the researchers who led the work, told WIRED in an email that the editor-in-chief of the journal had legal scientists to touch the media once the article had been accepted prior to publication, due to the importance for public fitness of the location that recovered people can be reinfected.

“Collective immunity is unlikely to eliminate SARS-CoV-2,” he and his co-authors wrote in the report. “Although it is imaginable that the next infections are more benign than the first, as in this patient.”

Throughout the pandemic, doctors and researchers around the world documented a handful of alleged covid-19 re-infections.In the first case, a woman in Japan made a full recovery before returning to the hospital three weeks later with a new set of symptoms.In China, France and the United States, patients spent up to six weeks between negative controls and new positive control, but these reports, which lacked systematic genetic analysis, were largely the result of faulty or abnormally long controls.Some cured patients may harbor genetic curtains of the virus in the nose and throat for months, long after symptoms have disappeared.This can result in positive effects on control even in the absence of an active infection.

“People assumed these reports weren’t genuine reinfections, but cases of widespread viral excretion,” says Susan Kline, infectious disease specialist and epidemiologist at the University of Minnesota. This case in Hong Kong, on the other hand, turns out to be the genuine deal. “The evidence here, with the virus sequences, is strong enough that this patient would be inflamed with another strain at the time,” he said.

Reinfection is possible, yes. But how unusual is this? It’s still not clear. Then, few samples taken from patients are used to extract a complete viral sequence, allowing this type of genetic detective work. And normal detection of other people without symptoms is only done in countries that have largely eliminated Covid-19. In the United States, where access to immediate testing is still random, such screening is only done for physical care personnel and inmate nursing homes and some prisons. “I suspect there’s probably more patients like that,” Kline says.

For now, there’s only one. This makes him say what reinfection will look like in other people, but at the time of infection, it turns out that this specific user lacked what immunologists call “sterilizing immunity,” says John Wherry, an immunologist at the University of Pennsylvania.This is when a user’s immune formula can absolutely stifle the virus’s ability to replicate, meaning that no infection occurs.

Actually, Wherry says, “it’s a top bar to fix.”At the moment the picture encounters a virus, it has a head that opposes intruders: neutralizing antibodies, which inhibit the proteins expressed from the invading pathogen and save it.These antibodies usually remain at a safe point after an initial infection or vaccine injection.But it’s an imperfect defense system. Even the most productive vaccines protect only 90-95% of the re-infection population, Wherry says., herbal infections with respiratory viruses almost leave any possibility of reinfection.Maybe at the moment, there aren’t enough antibodies to the hand: they would possibly have been reduced or the frame didn’t cause much reaction in the first place.Antibodies are not perfectly able to connect the proteins the virus uses to adhere to a cell.In this case, some viruses eventually enter the inside and begin to replicate.A new infection has begun.

What makes an infection a disease depends largely on what follows. During infection number one, the picture had never noticed the virus before, so it is blocked by creating a personalized immune reaction from scratch: an army of B-cells that help create antibodies that express the virus proteins and T cells that help identify viral components. and they. inflamed cells. But as those forces accumulate, the virus has a wonderful window of opportunity, perhaps from a week to 10 days, Wherry believes, to reproduce and spread. “At that moment, the virus spreads through the lungs and outdoors through the lungs, and when the infantry soldiers appear, you have a big challenge in your hands,” he says.

In later infections, there is a bit of delay when those cells “wake up” and act, Wherry says, but it’s a faster procedure than before, meaning the virus has less time to spread and infect new cells.the virus remains in the nose and nasopharynge, where a swab pattern may trip over it, but has not yet penetrated deeper into the airways, where it can cause a more serious illness.”It’s not near the length of the forest chimney.”I would have in 10 days,” says Wherry.In other words, the immune reaction takes care of the virus before the user gets sick.

And, he adds, the immune formula is more in position than ever to combat upcoming exposures. The effect is similar to that of a booster after a vaccine, to make sure that the immune reaction actually holds.

At least that’s how immunity deserves to work, in theory, but this patient’s story alone has many unknowns.One limitation, Wherry says, is that there seems to be little knowledge about the patient’s reaction to their first infection: what type of immune mobile directory they evolved and what point of neutralizing antibodies were generated and maintained at the time of reinfection.All of those points can also explain why this user had no symptoms of disease at the time.In some other user, due to differences in its frame or how its first episode of disease progressed, at one point the infection would possibly end up being more severe.Larger population studies are needed that track other people, and all the complexities of their immune reactions, to perceive how reinfection with SARS-CoV-2 could work, Wherry says.

For immunologists, it’s good news that this specific patient has no symptoms at this time, but for scientists who read the spread of the disease, the revelation is more disturbing: other asymptomatic people have already proven to be a major challenge in containing Covid-19.

The researchers did not directly demonstrate that this patient was able to spread the virus, which would require developing the live virus extracted from his airway, but it is safe to assume that this user was infectious, depending on the amount of virus detected through the researchers.Pedro Piedra, who studies infectious respiratory diseases at Baylor School of Medicine, but we don’t know how long they’ve been being contagious.per week or more required for maximum patients with Covid-19.”This was possibly shorter than the initial infection,” Piedra says.This is not unusual with so-called “revolutionary” infections that occur despite vaccination.In the Hong Kong report, researchers did not attempt to grow the virus from daily samples, to see if it can also infect living cells.Kwok-yung told WIRED in an email that his team is conducting those studies lately.

This will help determine whether other people going through a reinfection may be infectious, but it is unclear how effective they can be for disease transmission. If a user does not have a cough or sneezing that causes viruses and only carries a viral load causing infections in the nose and lungs for a few days, will it be paramount in new infections?It’s hard to say. The report did not imply whether competitive efforts to seek contacts in Hong Kong had discovered others whose patients had become ill at the time of infection.

This is an unresolved critical factor in perceiving the long-term evolution of the pandemic, says Bill Hanage, an epidemiologist for T infectious diseases.C.Chan School of Public Health at Harvard.He recently joined several other scientists to suggest that some of the hardest-hit cities would possibly be closer to collective immunity than classical calculations predict.

This calculation starts simple. Take the so-called epidemic reproductive number, R0 – how many people, on average, an inflamed user will transmit the virus – and insert it into the following formula: 1 – (1/ R0).This gives you the threshold of collective immunity, or what percentage of the population will need to become immune before the virus stops spreading at an accelerated rate.But it temporarily becomes complicated, because this formula assumes that all individuals are equally vulnerable to the virus and that everyone behaves randomly, that is, it has an equivalent chance of infecting all other Americans in its community.This, of course, is not the case.

More confusing models review to capture how other people behave in the genuine world One of these models predicts that collective immunity can be achieved with only 43% of the population exposed to the virus, because the connective tissue of society: other young people and an essential staff – will inflate sooner and create a wall of immunity around the most isolated and vulnerable groups , but these models depend on the concept that other people who in their first fight against the disease can no longer transmit the virus.

If it’s the norm for other people to move from category to delicate after just a few months, it can also radically replace the calculations.Now, the number of times each member of the population can inflame is no more than 1.And if those other people never feel sick, they might not take as many precautions to isolate themselves.”If this leads to many other people who don’t know they’re swollen, it can also be a problem.”Says Hanage.

Of course, it all depends on the extent to which other inflamed people can continue to spread the disease for a moment (or third or fourth) time and Hanage suspects that fewer symptoms mean less viral load, which means less transmission.This would allow anything, closer to the original calculation of collective immunity to maintain.Still, he says, relying on spring immunity is a harmful game.”Any virus that spreads through the respiratory tract of others who do not know they are inflamed will be difficult to control.contain,” he says.

Wherry goes even further. “It tells us that we have to be very careful with last week’s fad when it comes to herd immunity that protects us all,” he says. For him, reinfection is rare, the option of repeat infections underscores the need for a vaccine as a component of a realistic pandemic exit strategy. If other people want a seasoning to prevent reinfection and to avoid infecting other people, it is more productive to do it with a vaccine. Hong Kong researchers note that this means that other inflamed people in the past might want to be included in vaccination plans if an effective vaccine was available.

However, it deserves to be repeated that the Hong Kong patient was just a case of Covid-19 among tens of millions and there are a limited number of things that you deserve to check to remove from an N 1 exam.With better-observed instances and closer genetic evaluation, scientists will begin to perceive how reinfection occurs and how vital it is to drive the additional spread of the disease.But as the pandemic enters its eighth month, with more than 200,000 new infections still on record each.day around the world, there’s a smart chance they’ll have a chance to locate themselves.

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