Reports of reinforcements with coronaviruses give rise to a nightmare: repeat of the disease, impotent vaccines, unrelated lockdown – without an epidemic.
A case study published on Monday about a 25-year-old man in Nevada has dismissed those fears. The person, who was not named, became ill the second time that he was infected with the virus, a pattern that is supposed to inhibit the immune system.
But these cases make the news just as they are rare, experts said: More than 38 million people worldwide are infected with coronovirus, and as of Monday, fewer than five of those cases have been confirmed by scientists.
Angela Rasmussen, a virologist at Columbia University in New York, said, “It’s small – it’s like a microliter-sized drop in the bucket, which has happened in many cases around the world.”
In most cases, a second fight with the virus produced a milk symptom or none at all. But for at least three people, including a patient in Ecuador, the disease was more severe the second time during the first infection. An 89-year-old woman died during another illness in the Netherlands.
As rare as these cases may be, they indicate that revision is possible, said Akiko Iwasaki, an immunologist at Yale University, who wrote a commentary alongside the Nevada case study published in The Lancet Infection Diseases.
Dr. Iwasaki said, “It is important to note that there are people who get remade, and in some of those cases you get worse disease.” “You still need to wear masks and practice social transition, even if you have once recovered from this infection.”
We asked experts what is known about infection with coronavirus, and what the event means for vaccination and the course of the epidemic.
Re-infection with coronavirus is an uncommon occurrence.
First, the good news: disappearing rebirth seems rare.
There have been three published cases of first confirmation since reported in Hong Kong on 24 August; Another 20 reports are awaiting scientific review.
But it is impossible to know how widespread the phenomenon is. To confirm a case of revision, scientists must look for significant differences in the genes of coronaviruses due to both diseases.
In the United States, where testing was a scarce resource this year, many were not tested until they were ill enough to be hospitalized. Nevertheless, their samples were generally not preserved for genetic analysis, making it impossible to confirm the suspect’s allegations.
Many people who reconsider may be undetermined. The Hong Kong man, for example, had no symptoms for the second time, and his infection was detected due to routine checks at the airport.
“There are a lot of people who are also exposing that there are no symptoms that we’ll never hear about,” said Marion Pepper, an immunologist at the University of Washington in Seattle.
People who have more severe other infections are more likely to be identified as they return to the hospital. But those are also likely to be rare, experts said.
Dr. Iwasaki said, “If it had been a very common incident, we would have seen thousands of cases.”
In most people, the immune system works as expected.
Infection can occur for any number of reasons: because the initial infection was very low, for example, or because the immune system compromised other health conditions. On this occasion, a patient may be exposed to a large amount of the virus that can seed an infection before responding to an immune response.
This variability is fully expected, experts said, and has been seen in patients with diseases such as measles and malaria.
Pediatrician of Harvard TH School of Public Health, Drs. Michael Mina said, “You’ll never have anything distributed with millions where you don’t have some very rare cases.”
For example, in Europe at least two patients had compromised immune systems, and an 89-year-old woman received chemotherapy. In other reinforced patients, a lack of genetic factors or some previous immune exposure has destroyed the body’s ability to fight another attack.
“There are some people who just don’t develop a good immune response to certain pathogens,” said Florian Kramer, an immunologist at the Econ School of Medicine in Mount Sinai. “What is the reason? We are not sure, but it is usually rare.
In a vast majority of known infected patients, experts said, the immune system must work against other pathogens.
“There are many different infections where you can expose the virus again, and we probably won’t know because you don’t have the symptoms,” Dr. The paper said. “And it can be an important part of boosting immunity.”
When the body is in contact with an unfamiliar virus, it is normal to first develop some immunity and then to increase that response with each additional risk. This phenomenon is well known in children, but it is less often seen in adults because they rarely encounter new viruses, Drs. Meena said.
“I think it’s important to recognize that recombination is literally inherent in the development of our immune system,” he said. “We sometimes miss talking about this with so many people who haven’t really studied the immune system.”
Resurgence of symptoms does not attest to rebirth.
For each confirmed case of revision, there are dozens of anecdotal reports of people who were ill and appeared to be ill, but then became ill again weeks to months later.
Significant data are usually missing in those cases, such as a confirmed laboratory diagnosis, or a virus sample that can be sequenced.
“The question is always, is this a real reinfection?” Dr. Kramer said. “Getting that kind of data is very challenging very often.”
In most of these cases, infection is unlikely. More likely, these people are experiencing a resurgence of symptoms associated with the original infection. The virus can set off an inflammatory response that can flare up even weeks later and cause symptoms such as fatigue and heart problems. In rare cases, some patients may develop a chronic low-grade infection with the virus that never goes away.
“Even with viruses that can cause acute infections such as the flu,” Dr. “If your immune system is sufficiently compromised, you may have a persistent infection,” Kramer said.
While these are not real reins, they are still worrying if they develop a new disease or hospitalization months after the initial infection, Dr. Rasmussen said. “If there is recurrence again and again, and people are getting seriously ill for a second time, it’s probably their own problem,” she said.
People with a second bout can pass the virus on to others.
People reborn without symptoms can still pass the virus on to others. For example, Hong Kong’s patient was isolated in a hospital, even though he had no symptoms. But his viral load was so high that he could pass the virus on to others.
“Obviously, that person was not ill, so it’s good for him, but it doesn’t bode well for the community,” Dr. Viper said.
But to be sure to be contagious, researchers may need to look for live viruses. South Korean researchers investigated hundreds of reports of recombination and were able to control them as actual cases after infectious viruses failed to grow from the samples.
Dr. Rasmussen said, “Similar procedures will be required to determine the probability of transmission in each patient,” I think that’s the only way you can get to the bottom of it. “
Vaccines can be important to prevent rein.
Reports of reinfection have raised concerns over whether vaccines for coronovirus will be effective and help communities regain population immunity. What is of concern is that the immunity produced by the vaccine will not be sufficient to prevent infection with the virus.
In reality, experts said, vaccines have a better chance of producing stronger immunity than natural infections with the virus.
For example, coronovirus is specifically dodging the body’s early immune alarms, buying valuable time to seed an infection. In some people, this interval eventually triggers a cascading immune exaggeration that may be more harmful than infection.
The intention of the vaccines is to unfollow the immune response without interference from the virus, and thus can avoid this inflammatory sequence. Vaccines can also be manipulated to enhance immune memory, thus producing more permanent, more protective responses.
Vaccine tests are designed for the absence of disease rather than infection, and it is unclear whether vaccines can suppress virus levels to prevent transmission to others.
Nevertheless, vaccine-induced immunity should outperform natural immunity, Drs. Rasmussen said, “I’m optimistic.”