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There are many theories, none entirely satisfying. An infectious hunter might encounter a deer, Dr. Mubareka noted, but if theyre good at hunting, she added, its a terminal event for the deer.
If an infected hiker sneezes and the wind is blowing in the right direction, it could cause an unlucky event, said Dr. Tony Goldberg, a veterinary epidemiologist at the University of Wisconsin-Madison. Or if people feed deer from their porch, they could be sharing more than just food.
And white-tailed deer are expert leapers, reaching heights of eight feet. If you want to fence deer out of a place, you have to be trying very hard, said Scott Creel, an ecologist at Montana State University. Deer would have no trouble jumping into alfalfa fields to graze alongside cattle, perhaps inviting a close encounter with a farmer, Dr. Creel said.
Transmission could also happen indirectly, through wastewater or discarded food or other human-generated trash. Deer, like most other animals, will sniff before they eat, Dr. Kapur said. And deer release their feces as they feed, creating conditions where other deer might forage in areas contaminated with waste, or snuffle around waste that has feed mixed in, experts say.
But its not clear how long the virus would remain viable in a polluted water source or on the surface of a half-eaten apple, or whether enough of it would be present to pose a transmission risk.
An intermediate host, such as an itinerant cat, might ferry the virus from humans to deer. Farmed deer, which have frequent contact with humans, might also pass the virus to their wild counterparts through an escapee or their feces, Dr. Seifert said. (More than 94 percent of the deer in one captive site in Texas carried antibodies for the virus, researchers found more than double the rate found in free-ranging deer in the state.)
There are many theories, none entirely satisfying. An infectious hunter might encounter a deer, Dr. Mubareka noted, but if theyre good at hunting, she added, its a terminal event for the deer.
If an infected hiker sneezes and the wind is blowing in the right direction, it could cause an unlucky event, said Dr. Tony Goldberg, a veterinary epidemiologist at the University of Wisconsin-Madison. Or if people feed deer from their porch, they could be sharing more than just food.
And white-tailed deer are expert leapers, reaching heights of eight feet. If you want to fence deer out of a place, you have to be trying very hard, said Scott Creel, an ecologist at Montana State University. Deer would have no trouble jumping into alfalfa fields to graze alongside cattle, perhaps inviting a close encounter with a farmer, Dr. Creel said.
Transmission could also happen indirectly, through wastewater or discarded food or other human-generated trash. Deer, like most other animals, will sniff before they eat, Dr. Kapur said. And deer release their feces as they feed, creating conditions where other deer might forage in areas contaminated with waste, or snuffle around waste that has feed mixed in, experts say.
But its not clear how long the virus would remain viable in a polluted water source or on the surface of a half-eaten apple, or whether enough of it would be present to pose a transmission risk.
An intermediate host, such as an itinerant cat, might ferry the virus from humans to deer. Farmed deer, which have frequent contact with humans, might also pass the virus to their wild counterparts through an escapee or their feces, Dr. Seifert said. (More than 94 percent of the deer in one captive site in Texas carried antibodies for the virus, researchers found more than double the rate found in free-ranging deer in the state.)
Unknown lineages of the virus that causes COVID-19 have been found in New York City's sewage, raising new concerns that the novel coronavirus is finding ways to escape immunity.
The lineages don't seem poised to break out and cause a new surge at this point. Their proportion has risen and fallen along with New York's case rates, and there's no sign that these versions of the virus are becoming more common over time. But the mutations seen in the mystery lineages are similar to those that allow the omicron variant to partially escape immunity from vaccination and previous infection, said John Dennehy, a virologist at The Graduate Center at City University New York, who co-led the research.
"The fact that the omicron variant came from somewhere unknown and that it shares quite a few of its mutations with the unknown variant we see in New York City, that does pose a pretty serious concern that whatever we're seeing could find the right combination of mutations that would make it highly transmissible," Dennehy told Live Science.
Related: Coronavirus variants: Here's how the SARS-CoV-2 mutants stack up
Also troubling: The researchers don't know where the new viral lineages come from. The lineages are found only in limited areas of the city, and they don't seem to be spreading from neighborhood to neighborhood. They might arise from chronically infected humans or perhaps from an animal reservoir but what animal? So far, there's no firm evidence for any option.
"Nothing makes perfect sense," said Marc Johnson, a virologist at the University of Missouri School of Medicine.
Many cities monitor wastewater to try to track the amount of SARS-CoV-2 circulating in the community. Because people begin shedding virus in fecal material before they feel sick or get tested, wastewater levels of the virus precede rises in cases that show up from testing by about three weeks, Johnson said.
But relatively few places do genetic sequencing of the virus material found in wastewater. Dennehy started working on genetic sequencing in New York after the alpha variant made clear that coronavirus mutations were going to be a force to be reckoned with. After Dennehy and his colleagues Monica Trujillo, also at CUNY, and Davida Smyth, now at Texas A&M San Antonio, appeared on an episode of the popular podcast This Week in Virology in April 2021, Johnson got in touch. He'd been doing similar sequencing in Missouri and was losing sleep at night over viral RNA sequences that didn't match anything in global databases of coronavirus variants.
"I was going crazy," Johnson told Live Science.
The Missouri variants disappeared in late April 2021, never to be seen again. But the researchers began to collaborate on more thorough sequencing of viral RNA found in New York City, wondering if they'd find the same sequences they'd seen in Missouri. They didn't. But they did find a cluster of completely new unknown sequences.
The researchers expanded their efforts, testing wastewater from all of the city's 14 wastewater treatment plants two times a month, ultimately building a record spanning from January 2021 to the present.
The researchers use a technique that doesn't allow them to sequence an entire viral genome, but which focuses on about half of the spike protein that the virus uses to get into cells.This region contains a key area called the receptor-binding domain (RBD). Many of the mutations that allow omicron to evade antibodies from vaccines or non-omicron infections sit on the RBD. So, too, do the mutations seen in the lineages found in the New York City wastewater. (The researchers use the word "lineages" to avoid confusion with the term "variants of concern" as used by the World Health Organization. But, Dennehy said, genetically speaking, they're the same concept: Sequences representing unique replicating populations of virus that are genetically related to one another.)
Related: 11 surprising facts about the immune system
The researchers studied four of these mystery lineages, dubbed WNY1, WNY2, WNY3 and WNY4. They found that all had abilities to partially or completely evade antibodies that easily snag the original SAR-CoV-2 virus. While blood plasma from vaccinated people or people with previous infections could partially neutralize all four lineages, this neutralization was reduced compared with the original virus.
"They were mutations exactly where you'd expect to find mutations if the virus were trying to evade an immune response," Johnson said.
So where are these mystery linages coming from? The researchers checked 5,000 other wastewater samples from around the globe and found the lineages only in seven samples, all from New York State. Whatever they are, they're homegrown.
There are a few hypotheses, none of them entirely satisfactory. The first is that they're coming from unsampled human infections. Only between 2.6% and 12.9% of New York City cases are sequenced at any given time, so it's entirely possible that rare variants of the virus could sneak under the radar. Perhaps the lineages are versions of the virus that infect the gut and aren't often found in the nose or throat, where PCR swabs go.
But there are problems with these possibilities. A few studies have compared virus from the gut with virus from the nose and throat, and so far, no one's seen a difference between the two, CUNY's Trujillo told Live Science. Also, the geographical range of the viral lineages is limited they're found in the catchment areas of only three of the 14 wastewater treatment plants in the city. If the source of the virus is humans, they're humans who don't move around much.
"We were thinking about humans that might be bedridden," Smyth told Live Science. "So long-term facility patients that are perhaps not mobile."
But that would be strange too. "It would be weird that it would spread within a local population and not go anywhere else," Johnson said.
Another possibility is that the carrier of these cryptic lineages isn't human. The mutations seen in the clusters are seen in a region of the genome associated with the virus becoming more adept at infecting rodents (which aren't easily infected by the original coronavirus). New York City's rats would be an appealing target for blame. There are a lot of them, they live in the sewers, and they don't travel far.
But the researchers could find no smoking gun linking rats to the variant. The team sequenced the wastewater for animal genes, essentially looking to find out who poops in the sewers besides people. Other than genes from the animals people eat for food (cows, pigs, chickens), the researchers found evidence of cat, dog and rat genetic material in the sewers. But none were highly prevalent. And the wastewater treatment plant with the highest proportion of mystery coronavirus had the lowest proportion of rat genes some weeks, rat genes weren't even detectable.
Meanwhile, the stray cat population probably isn't big enough to sustain the amount of transmission the researchers inferred from the wastewater, and pet cats don't interact often with other pet cats either, Johnson said. Dogs are known to get COVID-19, but these mutations haven't been seen in dog virus cases before. And it would be very strange if a version of COVID-19 were circulating in dogs but not humans, Smyth said, given how close New Yorkers are to their pups.
The answer to the mystery may lie in sequencing more viral genomes from more animals on a regular basis. Smyth, in Texas, is working to get access to petting zoos to see if she can find new viral variants in different species. Testing the sewage upstream from the wastewater treatment plant in order to narrow down the source to a smaller area would also be helpful, Dennehy said, but much of that work is now moving into the purview of the Centers for Disease Control and Prevention (CDC), so Dennehy and his team will no longer have much access to upstream wastewater sources.
The omicron variant seemed to appear out of nowhere: It evolved from an earlier lineage than the delta variant that was, at the time, dominant. Its origin is a mystery. To Dennehy, Johnson and their colleagues, the origin of the next variant will remain a mystery, too, unless a more robust effort is put into place to understand where variants come from. Scientists already take regular samples of influenza from bird populations and raise the red flag when new strains that could potentially jump to people start circulating. Something similar may be possible with wastewater and regular animal sampling for SARS-CoV-2 if research agencies prioritize funding that kind of science.
"What we are looking at here is the mechanism or potential mechanism through which different variants arise," Trujillo said. "This is where we should be doing the research."
The findings appeared Feb. 3 in the journal Nature Communications.
Originally published on Live Science.
Unknown lineages of the virus that causes COVID-19 have been found in New York City's sewage, raising new concerns that the novel coronavirus is finding ways to escape immunity.
The lineages don't seem poised to break out and cause a new surge at this point. Their proportion has risen and fallen along with New York's case rates, and there's no sign that these versions of the virus are becoming more common over time. But the mutations seen in the mystery lineages are similar to those that allow the omicron variant to partially escape immunity from vaccination and previous infection, said John Dennehy, a virologist at The Graduate Center at City University New York, who co-led the research.
"The fact that the omicron variant came from somewhere unknown and that it shares quite a few of its mutations with the unknown variant we see in New York City, that does pose a pretty serious concern that whatever we're seeing could find the right combination of mutations that would make it highly transmissible," Dennehy told Live Science.
Related: Coronavirus variants: Here's how the SARS-CoV-2 mutants stack up
Also troubling: The researchers don't know where the new viral lineages come from. The lineages are found only in limited areas of the city, and they don't seem to be spreading from neighborhood to neighborhood. They might arise from chronically infected humans or perhaps from an animal reservoir but what animal? So far, there's no firm evidence for any option.
"Nothing makes perfect sense," said Marc Johnson, a virologist at the University of Missouri School of Medicine.
Many cities monitor wastewater to try to track the amount of SARS-CoV-2 circulating in the community. Because people begin shedding virus in fecal material before they feel sick or get tested, wastewater levels of the virus precede rises in cases that show up from testing by about three weeks, Johnson said.
But relatively few places do genetic sequencing of the virus material found in wastewater. Dennehy started working on genetic sequencing in New York after the alpha variant made clear that coronavirus mutations were going to be a force to be reckoned with. After Dennehy and his colleagues Monica Trujillo, also at CUNY, and Davida Smyth, now at Texas A&M San Antonio, appeared on an episode of the popular podcast This Week in Virology in April 2021, Johnson got in touch. He'd been doing similar sequencing in Missouri and was losing sleep at night over viral RNA sequences that didn't match anything in global databases of coronavirus variants.
"I was going crazy," Johnson told Live Science.
The Missouri variants disappeared in late April 2021, never to be seen again. But the researchers began to collaborate on more thorough sequencing of viral RNA found in New York City, wondering if they'd find the same sequences they'd seen in Missouri. They didn't. But they did find a cluster of completely new unknown sequences.
The researchers expanded their efforts, testing wastewater from all of the city's 14 wastewater treatment plants two times a month, ultimately building a record spanning from January 2021 to the present.
The researchers use a technique that doesn't allow them to sequence an entire viral genome, but which focuses on about half of the spike protein that the virus uses to get into cells.This region contains a key area called the receptor-binding domain (RBD). Many of the mutations that allow omicron to evade antibodies from vaccines or non-omicron infections sit on the RBD. So, too, do the mutations seen in the lineages found in the New York City wastewater. (The researchers use the word "lineages" to avoid confusion with the term "variants of concern" as used by the World Health Organization. But, Dennehy said, genetically speaking, they're the same concept: Sequences representing unique replicating populations of virus that are genetically related to one another.)
Related: 11 surprising facts about the immune system
The researchers studied four of these mystery lineages, dubbed WNY1, WNY2, WNY3 and WNY4. They found that all had abilities to partially or completely evade antibodies that easily snag the original SAR-CoV-2 virus. While blood plasma from vaccinated people or people with previous infections could partially neutralize all four lineages, this neutralization was reduced compared with the original virus.
"They were mutations exactly where you'd expect to find mutations if the virus were trying to evade an immune response," Johnson said.
So where are these mystery linages coming from? The researchers checked 5,000 other wastewater samples from around the globe and found the lineages only in seven samples, all from New York State. Whatever they are, they're homegrown.
There are a few hypotheses, none of them entirely satisfactory. The first is that they're coming from unsampled human infections. Only between 2.6% and 12.9% of New York City cases are sequenced at any given time, so it's entirely possible that rare variants of the virus could sneak under the radar. Perhaps the lineages are versions of the virus that infect the gut and aren't often found in the nose or throat, where PCR swabs go.
But there are problems with these possibilities. A few studies have compared virus from the gut with virus from the nose and throat, and so far, no one's seen a difference between the two, CUNY's Trujillo told Live Science. Also, the geographical range of the viral lineages is limited they're found in the catchment areas of only three of the 14 wastewater treatment plants in the city. If the source of the virus is humans, they're humans who don't move around much.
"We were thinking about humans that might be bedridden," Smyth told Live Science. "So long-term facility patients that are perhaps not mobile."
But that would be strange too. "It would be weird that it would spread within a local population and not go anywhere else," Johnson said.
Another possibility is that the carrier of these cryptic lineages isn't human. The mutations seen in the clusters are seen in a region of the genome associated with the virus becoming more adept at infecting rodents (which aren't easily infected by the original coronavirus). New York City's rats would be an appealing target for blame. There are a lot of them, they live in the sewers, and they don't travel far.
But the researchers could find no smoking gun linking rats to the variant. The team sequenced the wastewater for animal genes, essentially looking to find out who poops in the sewers besides people. Other than genes from the animals people eat for food (cows, pigs, chickens), the researchers found evidence of cat, dog and rat genetic material in the sewers. But none were highly prevalent. And the wastewater treatment plant with the highest proportion of mystery coronavirus had the lowest proportion of rat genes some weeks, rat genes weren't even detectable.
Meanwhile, the stray cat population probably isn't big enough to sustain the amount of transmission the researchers inferred from the wastewater, and pet cats don't interact often with other pet cats either, Johnson said. Dogs are known to get COVID-19, but these mutations haven't been seen in dog virus cases before. And it would be very strange if a version of COVID-19 were circulating in dogs but not humans, Smyth said, given how close New Yorkers are to their pups.
The answer to the mystery may lie in sequencing more viral genomes from more animals on a regular basis. Smyth, in Texas, is working to get access to petting zoos to see if she can find new viral variants in different species. Testing the sewage upstream from the wastewater treatment plant in order to narrow down the source to a smaller area would also be helpful, Dennehy said, but much of that work is now moving into the purview of the Centers for Disease Control and Prevention (CDC), so Dennehy and his team will no longer have much access to upstream wastewater sources.
The omicron variant seemed to appear out of nowhere: It evolved from an earlier lineage than the delta variant that was, at the time, dominant. Its origin is a mystery. To Dennehy, Johnson and their colleagues, the origin of the next variant will remain a mystery, too, unless a more robust effort is put into place to understand where variants come from. Scientists already take regular samples of influenza from bird populations and raise the red flag when new strains that could potentially jump to people start circulating. Something similar may be possible with wastewater and regular animal sampling for SARS-CoV-2 if research agencies prioritize funding that kind of science.
"What we are looking at here is the mechanism or potential mechanism through which different variants arise," Trujillo said. "This is where we should be doing the research."
The findings appeared Feb. 3 in the journal Nature Communications.
Originally published on Live Science.
A wave of polls taken as the Omicron variant crested across much of the United States shows new signs that the publics resolve to combat the coronavirus pandemic is waning.
The surveys depict an increasingly frustrated and pessimistic nation that is as worried by the specter of an endless pandemic as it is fearful of the disease. While a majority of voters remain concerned about the coronavirus, the balance of recent polling suggests that the desire to return to normalcy has approached or even overtaken alarm about the virus itself.
A recent Yahoo News/YouGov survey found that 46 percent of respondents thought Americans should learn to live with the pandemic and get back to normal, while just 43 percent thought we need to do more to vaccinate, wear masks and test.
A Republican firm, Echelon Insights, had similar findings, reporting that 55 percent of voters thought Covid-19 should be treated as an endemic disease that will never fully go away, like the flu, while 38 percent said it should be treated as a public health emergency.
The results are especially striking at a time when coronavirus cases, hospitalizations and even deaths are near record highs. Indeed, the same polls showed that the publics concern about the virus increased during the Omicron wave. But in a telling indication of the publics attitudes toward the pandemic, greater worry about the virus has not translated to greater support for measures to stop its spread.
Instead, fears of the virus apparently have been outweighed by mounting frustration with the inconveniences of a pandemic that has stretched into its second year. Three-quarters of adults described themselves as tired or frustrated with the pandemic in a recent Kaiser Family Foundation survey.
Fully 70 percent of Americans agreed with the statement that its time we accept Covid is here to stay and we just need to get on with our lives in a recent poll by Monmouth University. That survey found that support for vaccine mandates has dropped to just 43 percent from 53 percent in September, while support for masking and social distancing guidelines dropped to 52 percent from 63 percent over the same period.
The findings come at a possible turning point in the pandemic, as several Democratic governors announced intentions to ease some mask mandates over the next month. The growing frustration with pandemic restrictions may help explain some of those early announcements even as cases reach record levels.
The polls create a delicate challenge for the Biden administration, which never regained its political standing since the rise of the Delta variant dashed last summers hopes of a return to normalcy. The growing unease with the pandemic seems to have added to the presidents political woes, and may help explain why the public disapproves of Mr. Bidens handling of the coronavirus for the first time.
But a majority of Democratic-leaning voters continue to support a more vigorous response to the pandemic, potentially limiting how quickly the administration can readjust to public opinion. Many Americans harbor serious concerns about the health risks presented by the virus; the Biden administration may not find it easy to bring them along, at least as long as cases and deaths remain at elevated levels.
Feb. 8, 2022, 10:31 p.m. ET
And while a majority of voters may be itching for a return to normalcy, the public does not necessarily want an immediate end to pandemic-related measures. While a new Axios/Ipsos poll found that a majority of voters wanted to move toward opening up, less than half of those respondents or just 21 percent of all Americans said they supported going back to life as usual with no coronavirus mandates or requirements.
With cases now declining across most of the country, it is possible that the publics tolerance for virus restrictions may wane along with the virus in the weeks ahead.
But for now, the public is not optimistic about Mr. Biden or anyone bringing the pandemic to an end. Even though many of the most onerous pandemic restrictions, like shutdowns or remote schooling for children, have largely come to an end, only 18 percent of Americans say their lives have returned to normal, according to another Axios/Ipsos poll. In the same survey, just 13 percent of people expected to get back to their normal pre-Covid lives within the next six months, down from 36 percent in June.
Johnson & Johnson vaccine. The company quietly paused vaccine productionat a key factory, raising concern over whether it can meet commitments to developing nations. It is not clear whether the halt has had an impact on vaccine supplies yet, thanks to stockpiles.
Only 15 percent of adults believed that the disruptions to travel, school and work would end this year, according to Gallup. And 28 percent of those polled by Monmouth believed that the country would never return to normal again, up from 9 percent a year earlier.
At the same time, the publics fears of the virus have gradually abated. Overall, 38 percent said they were very concerned about someone they know becoming seriously ill, according to the Monmouth poll. Thats up slightly from 30 percent in December, before the Omicron variant spread, but beneath the 45 percent who said the same at the peak of the Delta surge in September, or the 60 percent who said they were very concerned before the vaccination campaign last spring.
The polls show that the public is, at best, divided on whether the virus itself is the most significant problem facing the nation. Many surveys show that the economy and inflation are now rated as the most important issue, and only about one-third of Americans say the pandemic is the most serious challenge.
The long-term decline in concern about the coronavirus likely relates to rising vaccination rates, but it may also reflect the diminished severity of the Omicron variant. Overall, 69 percent of adults said they were less worried about how Omicron will affect them personally than in prior waves of variants, according to the Kaiser Family Foundation poll. Instead, a majority of Americans said they were more worried about the effect of Omicron on the economy and local hospitals.
Apparently, those societal concerns have not been enough to spur individuals to take action to check the pandemic. The Kaiser poll found that a majority of adults said they were no likelier to wear a mask, avoid large gatherings, get a vaccine or a booster shot as a result of Omicron.
As the Omicron variant of the coronavirus drives new waves of COVID infections around the world, some early studies appear to show the risk of reinfection has risen.
According to an analysis by the United Kingdoms Office for National Statistics (ONS), the risk of reinfection is 16 times higher when Omicron was the dominant variant, compared with the period when Delta was dominant.
The analysis also showed that unvaccinated people were twice as likely to be reinfected than those who had their second dose of vaccine in the previous 14 to 89 days.
With infection rates continuing to surge across most regions around the world and as the number of reinfections also climbs, experts have said that protection from previous infections or vaccines declines over time.
A reinfection is a medical condition that usually occurs when a person becomes infected with COVID-19, recovers, and then gets infected again. It could happen with any of the variants of the coronavirus.
According to the United States Centers for Disease Control and Prevention (CDC), a reinfection is considered such if the patient tests positive again 90 days or more after their first positive test. The same standard has been established by the UK Health Security Agency (UKHSA).
The 90-day period has been chosen because some patients continue to have the virus in their systems for longer than the average of about two weeks, making it difficult to distinguish between an infection or a reinfection within this time frame.
The majority of patients with normal immunity do not have the virus beyond 10-14 days, but some harbour it for a longer time and therefore the time has been extended to three months, Dr Pere Domingo, currently senior consultant and HIV/AIDS programme director at the Infectious Diseases Unit of the Hospital de la Santa Creu i Sant Pau, told Al Jazeera.
According to a report published by the UKs ONS in June 2021, reinfections were considered rare, but the rate of reinfections has increased since the Omicron variant became the dominant strain in late 2021.
An analysis published last week by the news agency Reuters, citing data collected by the UKHSA, suggested that suspected reinfections accounted for approximately 10 percent of confirmed cases in England in January. Suspected reinfections made up fewer than 2 percent of cases in the six months prior to December 6. A total of 588,000 possible reinfections have been registered in England.
Meanwhile in Italy, 3 percent of the new cases were reinfections, up from about 1.5 percent before Omicron, a spokesperson for Italys National Institute of Health said last week.
Dr Domingo noted that the Omicron variant has mutated significantly compared with other variants, meaning that protection developed against previous variants could be less effective against Omicron.
Omicron has mutated many times, Dr Domingo said. These mutations have changed the antigens, the proteins are no longer the same as they were in Delta, nor the strain that came out in Wuhan.
Therefore, the antibodies that one could develop against the original strain or against Delta, are no longer useful for Omicron, he added.
According to the research by Imperial College London, the protection afforded by the past infection may be as low as 19 percent.
Viruses are constantly evolving and these changes naturally lead to the emergence of new strains that can lead to new infections.
There is always a struggle between the forces of the individual and immunity on the one hand and the virus on the other, Dr Domingo said.
And the way the virus fights is by changing, by making mutations that will allow it to avoid the patients antibodies, he added.
According to research from South Africa, people infected with Omicron developed an antibody response to the current and previous strains. However, according to the Gavi vaccine alliance, the immunity from a Delta infection provides limited protection against Omicron.
Previous infections or vaccines will provide protection, and the greater the exposure to the virus leads to greater protection, but the immunity is not complete and it declines over time, Dr Domingo said.
And if the virus changes, the protection generated by infection, is overwhelmed.
According to early research, reinfections are generally mild. A study done in the state of Qatar found that reinfections have 90 percent lower odds of resulting in hospitalisation or death than primary infections.
Dr William Schaffner, professor of medicine at Vanderbilt University Medical Center, said the severity of a reinfetion depends on the patients immune system.
If you are immuno-compromised, or if you are a person who is frail, or sick, then I would think a second infection could potentially be serious enough to put you in the hospital, but if you have a normal immune system, the second infection is not likely to be severe, he added.
Experts said a reinfection would provide some level of immunity against any potential reinfection in the future, but the best immunity is the result of a hybrid immunity.
Hybrid immunity is the result of having been both infected and vaccinated against the virus. According to research, this could generate a super-immune response.
However, there is a risk in the long term effects of the infection.
Anyone who recovers from COVID stands or risk of developing so-called Long COVID, Dr Schaffner said.
[And so far] we have no information, on whether second infections are more likely to result in Long COVID than first infections, he added.
Experts have said the current guidance in place to combat COVID-19 are still effective. The World Health Organization (WHO) has recommended people get vaccinated.
It also advised people to maintain physical distance, avoid crowds and close contacts, wear a properly fitted mask, clean your hands frequently, and cover your mouth and nose when coughing or sneezing.
We need people to keep [following] all these measures, Dr Ali Fattom said.
Precautions are very important, not only for the person itself, but you dont want to transmit the virus to others and put them at risk, he added.
As the Omicron variant of the coronavirus drives new waves of COVID infections around the world, some early studies appear to show the risk of reinfection has risen.
According to an analysis by the United Kingdoms Office for National Statistics (ONS), the risk of reinfection is 16 times higher when Omicron was the dominant variant, compared with the period when Delta was dominant.
The analysis also showed that unvaccinated people were twice as likely to be reinfected than those who had their second dose of vaccine in the previous 14 to 89 days.
With infection rates continuing to surge across most regions around the world and as the number of reinfections also climbs, experts have said that protection from previous infections or vaccines declines over time.
A reinfection is a medical condition that usually occurs when a person becomes infected with COVID-19, recovers, and then gets infected again. It could happen with any of the variants of the coronavirus.
According to the United States Centers for Disease Control and Prevention (CDC), a reinfection is considered such if the patient tests positive again 90 days or more after their first positive test. The same standard has been established by the UK Health Security Agency (UKHSA).
The 90-day period has been chosen because some patients continue to have the virus in their systems for longer than the average of about two weeks, making it difficult to distinguish between an infection or a reinfection within this time frame.
The majority of patients with normal immunity do not have the virus beyond 10-14 days, but some harbour it for a longer time and therefore the time has been extended to three months, Dr Pere Domingo, currently senior consultant and HIV/AIDS programme director at the Infectious Diseases Unit of the Hospital de la Santa Creu i Sant Pau, told Al Jazeera.
According to a report published by the UKs ONS in June 2021, reinfections were considered rare, but the rate of reinfections has increased since the Omicron variant became the dominant strain in late 2021.
An analysis published last week by the news agency Reuters, citing data collected by the UKHSA, suggested that suspected reinfections accounted for approximately 10 percent of confirmed cases in England in January. Suspected reinfections made up fewer than 2 percent of cases in the six months prior to December 6. A total of 588,000 possible reinfections have been registered in England.
Meanwhile in Italy, 3 percent of the new cases were reinfections, up from about 1.5 percent before Omicron, a spokesperson for Italys National Institute of Health said last week.
Dr Domingo noted that the Omicron variant has mutated significantly compared with other variants, meaning that protection developed against previous variants could be less effective against Omicron.
Omicron has mutated many times, Dr Domingo said. These mutations have changed the antigens, the proteins are no longer the same as they were in Delta, nor the strain that came out in Wuhan.
Therefore, the antibodies that one could develop against the original strain or against Delta, are no longer useful for Omicron, he added.
According to the research by Imperial College London, the protection afforded by the past infection may be as low as 19 percent.
Viruses are constantly evolving and these changes naturally lead to the emergence of new strains that can lead to new infections.
There is always a struggle between the forces of the individual and immunity on the one hand and the virus on the other, Dr Domingo said.
And the way the virus fights is by changing, by making mutations that will allow it to avoid the patients antibodies, he added.
According to research from South Africa, people infected with Omicron developed an antibody response to the current and previous strains. However, according to the Gavi vaccine alliance, the immunity from a Delta infection provides limited protection against Omicron.
Previous infections or vaccines will provide protection, and the greater the exposure to the virus leads to greater protection, but the immunity is not complete and it declines over time, Dr Domingo said.
And if the virus changes, the protection generated by infection, is overwhelmed.
According to early research, reinfections are generally mild. A study done in the state of Qatar found that reinfections have 90 percent lower odds of resulting in hospitalisation or death than primary infections.
Dr William Schaffner, professor of medicine at Vanderbilt University Medical Center, said the severity of a reinfetion depends on the patients immune system.
If you are immuno-compromised, or if you are a person who is frail, or sick, then I would think a second infection could potentially be serious enough to put you in the hospital, but if you have a normal immune system, the second infection is not likely to be severe, he added.
Experts said a reinfection would provide some level of immunity against any potential reinfection in the future, but the best immunity is the result of a hybrid immunity.
Hybrid immunity is the result of having been both infected and vaccinated against the virus. According to research, this could generate a super-immune response.
However, there is a risk in the long term effects of the infection.
Anyone who recovers from COVID stands or risk of developing so-called Long COVID, Dr Schaffner said.
[And so far] we have no information, on whether second infections are more likely to result in Long COVID than first infections, he added.
Experts have said the current guidance in place to combat COVID-19 are still effective. The World Health Organization (WHO) has recommended people get vaccinated.
It also advised people to maintain physical distance, avoid crowds and close contacts, wear a properly fitted mask, clean your hands frequently, and cover your mouth and nose when coughing or sneezing.
We need people to keep [following] all these measures, Dr Ali Fattom said.
Precautions are very important, not only for the person itself, but you dont want to transmit the virus to others and put them at risk, he added.
A growing number of governments, politicians and top health officials are saying its time to start living with the virus.
The argument is that the Omicron variant of the coronavirus causes milder illness, which presents less of a threat on an individual level. Additionally, after Omicron, so many people will have some form of immunity through either vaccination or infection that subsequent waves may be smaller and more manageable.
But are you ready?
Were asking readers how they feel about being asked to start living with the virus and what that phrase means to them. If youd like to participate, you can fill out this form below. We may use your response in an upcoming newsletter.
