Some countries around the world are witnessing a record rise in the number of coronavirus (COVID-19) cases after the emergence of the Omicron variant. The 'variant of concern' Omicron was detected in November last year and was speculated to be the most worrying Covid variant since delta with a large number of mutations.

Some countries around the world are witnessing a record rise in the number of coronavirus (COVID-19) cases after the emergence of the Omicron variant. The 'variant of concern' Omicron was detected in November last year and was speculated to be the most worrying Covid variant since delta with a large number of mutations. It appeared to be true when Covid cases saw a record rise in countries like the United Kingdom, and some Southern African countries, putting pressure on the frontline workers with an increase in hospitalisations. As the world continues to fight against the deadly and highly transmissible Covid variants, the question is - what's next? When the pandemic will end? Is Omicron the endgame? Will there be more variants? What is the Omicron 'sub-variant'? Experts say... Infectious disease experts have hinted that may be an end in sight. As quoted by CNN, Dr Tom Frieden said, "I think if we do it right, we're going to have a 2022 in which Covid doesn't dominate our lives so much." Frieden was director of the US Centers for Disease Control and Prevention under former United States President Barack Obama. He is now the CEO and president of Resolve to Save Lives. ALSO READ | Rio de Janeiro postpones Carnival parades as Omicron cases spike During Omicron predominance, vaccine efficacy against Covid hospitalization was 81% among adults who had received their second dose less than six months earlier, 57% among those who had received it more than six months earlier, and 90% after a third dose. https://t.co/y5SBmxoADX — Dr. Tom Frieden (@DrTomFrieden) January 21, 2022 × Dr Yvonne Maldonado, who is an epidemiologist and infectious disease specialist at Stanford Medicine, and some other experts talked about the next phase of the pandemic and what will happen next. "We really don't know exactly," Maldonado said. "None of us really anticipated Omicron. Well, there were hints, but we did not expect it to happen exactly the way it did," Maldonado said. Meanwhile, the experts believe what has happened in South Africa can happen in other parts of the world. "South Africa's kind of our canary in the coal mine because they were able to pick up the Omicron variant first," Maldonado said. ALSO READ | This COVID-free island gets 36 positive cases on its first international flight In South Africa, where the Omicron variant was first reported, cases peaked but fell off quickly. Experts think will happen everywhere as the UK also saw a similar trend. DrJohn Swartzberg, who is an expert in infectious diseases and vaccinology, said as quoted by CNN, "I anticipate in the short run -- being the next six weeks, four to six weeks -- that it's still going to be pretty rough." Swartzberg is also a clinical professor emeritus at the University of California, Berkeley's School of Public Health. The report also mentioned Swartzberg as saying that maybe the cases will start declining in March. "There will be a sense of optimism, and then we will be able to do more things in our lives. I think May or June is going to really look up for us. I'm quite optimistic," Swartzberg said. Next variants? As of now, the cases are rising. For example, Tokyo recorded its highest number of daily COVID-19 infections for the fourth consecutive day on Saturday. The capital city had 11,227 new coronavirus cases, the local government said. The case count jumped nearly 2.5 times from 4,561 lodged a week before and was higher than 9,699 confirmed cases on Friday. The Russian government on Saturday reported a record number of new coronavirus cases. As reported, Russia registered 57,212 new daily cases, surging past the previous record set Friday of 49,513. When the cases are rising, it's difficult to anticipate what will happen next. Dr George Rutherford, who is an epidemiologist at the University of California, San Francisco said as quoted by CNN, "It's not at all clear what comes next." As per the report, he said that the virus could see gradual mutations, similar to Alpha and Beta variants. Maybe could behave like Delta and Omicron with a large jump. Omicron 'sub-variant' Some experts are optimistic but Omicron 'sub-variant' is posing threats as scientists are keeping a close watch on a recently-discovered sub-variant version virus. Scientists are probing how the sub-variant could affect future pandemic spread. British health authorities have notably identified hundreds of cases of the latest version, dubbed BA.2, while international data suggest it could spread relatively quickly. The UK Health Security Agency (UKHSA) identified more than 400 cases in Britain in the first ten days of this month and has indicated the latest variant has been detected in some 40 other countries, accounting for a majority of most recent cases in some nations including India, Denmark and Sweden. The UKHSA indicated Friday (January 21) it had designated the BA.2 sub-lineage as a variant under investigation (VUI) as cases of it were on the increase even if, in Britain, the BA.1 lineage currently remains dominant. As per the authority, "there is still uncertainty around the significance of the changes to the viral genome." It is required surveillance as, in parallel, cases in recent days showed a sharp rise in BA.2 incidence notably in India and Demark. ×

Will COVID-19 start diminishing in 2022 or the world will see new variants?

As the world battles the Delta variant, World Health Organization (WHO) has identified a new coronavirus strain that may be able to bypass vaccines' effect.<o:p></o:p>

In WHO’s weekly bulletin on the COVID-19 pandemic, the organisation talked about the new variant dubbed as Mu, or B.1.621, which was first identified in Colombia in January 2021.

Also read |&nbsp;<a href="https://www.wionews.com/world/number-of-organ-transplants-dip-as-covid-19-grips-world-409653" hreflang="en">Number of organ transplants dip as COVID-19 grips world</a>

<o:p></o:p>

Experts explained that this new variant of <a href="https://www.wionews.com/topics/coronavirus">coronavirus</a> has been mutating. This has led the scientists to believe that the Mu variant might be resistant to the existing vaccines. This has reminded the experts about the situation with the Beta variant. However, the WHO has also cautioned people that more studies are needed to examine this variant and its resistance further.<o:p></o:p>

"Since its first identification in Colombia in January 2021, there have been a few sporadic reports of cases of the Mu variant and some larger outbreaks have been reported from other countries in South America and in Europe," the bulletin read.

<o:p>Also read |&nbsp;<a href="https://www.wionews.com/science/what-is-the-west-nile-virus-the-infection-russia-has-warned-may-spread-409520">What is the West Nile virus, the infection Russia has warned may spread?</a></o:p>

While the totality rate of growth has not been alarming yet, its spread in Colombia and Ecuador is increasing. "Although the global prevalence of the Mu variant among sequenced cases has declined and is currently below 0.1%, the prevalence in Colombia (39%) and Ecuador (13%) has consistently increased," the bulletin explained. "The epidemiology of the Mu variant in South America, particularly with the co-circulation of the Delta variant, will be monitored for changes."<o:p></o:p>

As of now, the world is fighting the deadly and wide spread of the Delta variant which was first identified by the scientists of India and has quickly spread across the world. Along with the Delta variant, there are three other variants of concern — Alpha variant, which was first recorded in England; Beta which has spread in 141 countries and Gamma which is now found in over 90 countries.<o:p></o:p>

Mu variant is the fifth variant of interest, for now, as per the WHO.<o:p></o:p>

As the world battles the Delta variant, World Health Organization (WHO) has identified a new coronavirus strain that may be able to bypass vaccines' effect. In WHO’s weekly bulletin on the COVID-19 pandemic, the organisation talked about the new variant dubbed as Mu, or B.

As the world battles the Delta variant, World Health Organization (WHO) has identified a new coronavirus strain that may be able to bypass vaccines' effect. In WHO’s weekly bulletin on the COVID-19 pandemic, the organisation talked about the new variant dubbed as Mu, or B.1.621, which was first identified in Colombia in January 2021. Also read | Number of organ transplants dip as COVID-19 grips world Experts explained that this new variant of coronavirus has been mutating. This has led the scientists to believe that the Mu variant might be resistant to the existing vaccines. This has reminded the experts about the situation with the Beta variant. However, the WHO has also cautioned people that more studies are needed to examine this variant and its resistance further. "Since its first identification in Colombia in January 2021, there have been a few sporadic reports of cases of the Mu variant and some larger outbreaks have been reported from other countries in South America and in Europe," the bulletin read. Also read | What is the West Nile virus, the infection Russia has warned may spread? While the totality rate of growth has not been alarming yet, its spread in Colombia and Ecuador is increasing. "Although the global prevalence of the Mu variant among sequenced cases has declined and is currently below 0.1%, the prevalence in Colombia (39%) and Ecuador (13%) has consistently increased," the bulletin explained. "The epidemiology of the Mu variant in South America, particularly with the co-circulation of the Delta variant, will be monitored for changes." As of now, the world is fighting the deadly and wide spread of the Delta variant which was first identified by the scientists of India and has quickly spread across the world. Along with the Delta variant, there are three other variants of concern — Alpha variant, which was first recorded in England; Beta which has spread in 141 countries and Gamma which is now found in over 90 countries. Mu variant is the fifth variant of interest, for now, as per the WHO.

WHO warns against a new Covid variant that may be resistant to vaccines

In South Africa, a new potential COVID-19 variant of interest (VOI) has been identified.

Scientists from the KwaZulu-Natal Research Innovation and Sequencing Platform and the National Institute for Communicable Diseases (NICD) of South Africa first spotted&nbsp;the strain&nbsp;in May 2021 during the third wave of Covid in the country.&nbsp;

Also read |&nbsp;<a href="https://www.wionews.com/world/warning-from-wuhans-bat-woman-new-covid-variants-will-continue-to-emerge-says-shi-zhengli-404383">Warning from Wuhan's 'bat woman': New Covid variants will continue to emerge, says Shi Zhengli</a>

Since then, the strain which has been assigned to the PANGO lineage C.1.2, has been&nbsp;detected in most of South Africa's provinces as well as in seven other countries across Africa, Europe, Asia and Oceania.

The variant is believed to have evolved from C.1,&nbsp;one of the lineages predominant during the first outbreak of <a href="https://www.wionews.com/topics/coronavirus">SARS-CoV-2</a> in South Africa.

According to the study's abstract C.1.2 is associated with&nbsp;reduced neutralisation sensitivity,&nbsp;as well as having increased transmissibility.

Also read |&nbsp;<a href="https://www.wionews.com/world/lambda-new-variant-of-covid-19-that-is-affecting-29-countries-392308">Lambda: New variant of COVID-19 that is affecting 29 countries</a>

Compared to C.1, the new variant has undergone substantial mutations and is further away from the original virus detected in Wuhan than any other variant of concern (VOC) or VOI detected so far around the world. 
 
Study results indicate that C.1.2 develops 41.8 mutations per year. This is an approximately 1.7-fold increase over the current global rate and an approximately 1.8-fold increase over the original SARS-CoV-2 evolution estimate.

Alpha, Beta, and Gamma VOCs also emerged after a similarly short period of increased evolution. The researchers suggest that one event, followed by amplification in the number of cases, was responsible for the faster mutation rate.

Also read |&nbsp;<a href="https://www.wionews.com/science/covid-19-all-you-need-to-know-about-delta-plus-variant-393450">COVID-19: All you need to know about Delta Plus variant</a>

Over half or 52 per cent of the spike mutations identified in C.1.2 have already been identified in other VOIs and VOCs. 
 
Moreover, the study found a consistent rise in the number of C.1.2 genomes each month in South Africa, rising from 0.2 per cent in May to 1.6 per cent in June and 2.0 per cent in July. Researchers noted this is similar to what was observed in Beta and Delta during early detection in South Africa. 
 
80 sequences matching the C.1.2 lineage are already listed on the open-access database GISAID (Global Initiative on Sharing Avian Influenza Data) as of August 20, 2021.

<div class="videoWrapper trancodeVideo"><iframe allowfullscreen="" autoplay="1" class="includeVideo" frameborder="0" height="350" src="https://www.wionews.com/videos/unvaccinated-teacher-infects-students-after-contracting-covid-19-409277/embed" style="width:100%;max-width:560px;" width="560"></iframe></div>

 
More study is needed "to determine the functional impact of these mutations, which likely include neutralising antibody escape, and to investigate whether it confers advantage over the Delta variant," says&nbsp;Cathrine Scheepers, from NICD.

These findings have been reported in a study that has yet to be peer-reviewed but is available on the medRxiv server.

(With inputs from agencies)

In South Africa, a new potential COVID-19 variant of interest (VOI) has been identified. Scientists from the KwaZulu-Natal Research Innovation and Sequencing Platform and the National Institute for Communicable Diseases (NICD) of South Africa first spotted the strain in May 2021 during the third wave of Covid in the country.

In South Africa, a new potential COVID-19 variant of interest (VOI) has been identified. Scientists from the KwaZulu-Natal Research Innovation and Sequencing Platform and the National Institute for Communicable Diseases (NICD) of South Africa first spotted the strain in May 2021 during the third wave of Covid in the country. Also read | Warning from Wuhan's 'bat woman': New Covid variants will continue to emerge, says Shi Zhengli Since then, the strain which has been assigned to the PANGO lineage C.1.2, has been detected in most of South Africa's provinces as well as in seven other countries across Africa, Europe, Asia and Oceania. The variant is believed to have evolved from C.1, one of the lineages predominant during the first outbreak of SARS-CoV-2 in South Africa. According to the study's abstract C.1.2 is associated with reduced neutralisation sensitivity, as well as having increased transmissibility. Also read | Lambda: New variant of COVID-19 that is affecting 29 countries Compared to C.1, the new variant has undergone substantial mutations and is further away from the original virus detected in Wuhan than any other variant of concern (VOC) or VOI detected so far around the world. Study results indicate that C.1.2 develops 41.8 mutations per year. This is an approximately 1.7-fold increase over the current global rate and an approximately 1.8-fold increase over the original SARS-CoV-2 evolution estimate. Alpha, Beta, and Gamma VOCs also emerged after a similarly short period of increased evolution. The researchers suggest that one event, followed by amplification in the number of cases, was responsible for the faster mutation rate. Also read | COVID-19: All you need to know about Delta Plus variant Over half or 52 per cent of the spike mutations identified in C.1.2 have already been identified in other VOIs and VOCs. Moreover, the study found a consistent rise in the number of C.1.2 genomes each month in South Africa, rising from 0.2 per cent in May to 1.6 per cent in June and 2.0 per cent in July. Researchers noted this is similar to what was observed in Beta and Delta during early detection in South Africa. 80 sequences matching the C.1.2 lineage are already listed on the open-access database GISAID (Global Initiative on Sharing Avian Influenza Data) as of August 20, 2021. More study is needed "to determine the functional impact of these mutations, which likely include neutralising antibody escape, and to investigate whether it confers advantage over the Delta variant," says Cathrine Scheepers, from NICD. These findings have been reported in a study that has yet to be peer-reviewed but is available on the medRxiv server. (With inputs from agencies)

New potential COVID-19 variant of concern identified in South Africa

In just a matter of weeks, two variants of the coronavirus have become so familiar that you can hear their inscrutable alphanumeric names regularly uttered on television news.

B.1.1.7, first identified in Britain, has demonstrated the power to spread far and fast. In South Africa, a mutant called B.1.351 can dodge human antibodies, blunting the effectiveness of some vaccines.

Scientists have also had their eye on a third concerning variant that arose in Brazil, called P.1. Research had been slower on P.1 since its discovery in late December, leaving scientists unsure of just how much to worry about it.

“I’ve been holding my breath,” said Bronwyn MacInnis, a public health researcher at the Broad Institute.

Now three studies offer a sobering history of P.1’s meteoric rise in the Amazonian city of Manaus. It likely arose there in November and then fueled a record-breaking spike of coronavirus cases. It came to dominate the city due in part to increased contagiousness, the research found.

But it also gained the ability to infect some people who had immunity from previous bouts of COVID-19. And laboratory experiments suggest that P.1 could weaken the protective effect of a Chinese vaccine now in use in Brazil.

The new studies have yet to be published in scientific journals. Their authors caution that findings on cells in laboratories do not always translate to the real world, and they’ve only begun to understand P.1’s behaviour.

“The findings apply to Manaus, but I don’t know if they apply to other places,” said Nuno Faria, a virus expert at Imperial College London who helped lead much of the new research.

But even with the mysteries that remain around P.1, experts said it is a variant to take seriously. “It’s right to be worried about P.1, and this data gives us the reason why,” said William Hanage, a public health researcher at the Harvard T.H. Chan School of Public Health.

P.1 is now spreading across the rest of Brazil and has been found in 24 other countries. In the United States, the Centers for Disease Control and Prevention has recorded six cases in five states: Alaska, Florida, Maryland, Minnesota and Oklahoma.

To reduce the risks of P.1 outbreaks and reinfections, Faria said it was important to double down on every measure we have to slow the spread of the coronavirus. Masks and social distancing can work against P.1. And vaccination can help drive down its transmission and protect those who do get infected from severe disease.

“The ultimate message is that you need to step up all the vaccination efforts as soon as possible,” he said. “You need to be one step ahead of the virus.”

Faria and his colleagues started tracking the coronavirus when it exploded in Brazil last spring. Manaus, a city of 2 million in the Brazilian Amazon, was hit particularly hard. At its springtime peak, the cemeteries of Manaus were overwhelmed by the bodies of the dead.

But after a peak in late April, Manaus seemed to have gotten past the worst of the pandemic. Some scientists thought that the drop meant Manaus had gained herd immunity.

Faria and his colleagues looked for coronavirus antibodies in samples from a Manaus blood bank in June and October. They determined that roughly three-quarters of the residents of Manaus had been infected.

But near the end of 2020, new cases began surging again. “There were actually far more cases than in the previous peak of cases, which had been in late April,” Faria said. “And that was very puzzling to us.”

Faria and his colleagues wondered if new variants might be partly to blame for the resurgence. In Britain, researchers were finding that B.1.1.7 was surging across the country.

To search for variants, Faria and his colleagues started a new genome sequencing effort in the city. While B.1.1.7 had arrived in other parts of Brazil, they didn’t find it in Manaus. Instead, they found a variant no one had seen before.

Many variants in their samples shared a set of 21 mutations not seen in other viruses circulating in Brazil. Faria sent a text message to a colleague: “I think I’m looking at something really strange, and I’m quite worried about this.”

A few mutations, in particular, worried him, because scientists had already found them in either B.1.1.7 or B.1.351. Experiments suggested that some of the mutations might make the variants better able to infect cells. Other mutations let them evade antibodies from previous infections or produced by vaccines.

As Faria and his colleagues analyzed their results, researchers in Japan were making a similar discovery. Four tourists returning home from a trip to the Amazon on Jan. 4 tested positive for the coronavirus. Genome sequencing revealed the same set of mutations Faria and his colleagues were seeing in Brazil.

Faria and his colleagues posted a description of P.1 on an online virology forum on Jan. 12. They then investigated why P.1 was so common. Its mutations may have made it more contagious, or it might have been lucky. By sheer chance, the variant might have shown up in Manaus just as the city was getting more relaxed about public health measures.

It was also possible that P.1 became common because it could reinfect people. Normally, coronavirus reinfections are rare, because the antibodies produced by the body after infection are potent for months. But it was possible that P.1 carried mutations that made it harder for those antibodies to latch onto it, allowing it to slip into cells and cause new infections.

The researchers tested these possibilities by tracking P.1 from its earliest samples in December. By early January, it made up 87% of samples. By February it had taken over completely.

Combining the data from genomes, antibodies and medical records in Manaus, the researchers concluded that P.1 conquered the city thanks not to luck but biology: Its mutations helped it spread. Like B.1.1.7, it can infect more people, on average, than other variants can. They estimate it is somewhere between 1.4 and 2.2 times more transmissible than other lineages of coronaviruses.

But it also gets an edge from mutations that let it escape antibodies from other coronaviruses. They estimate that in 100 people who were infected in Manaus last year, somewhere between 25 and 61 of them may have been reinfected by P.1.

The researchers found support for this conclusion in an experiment in which they mixed P.1 viruses with antibodies from Brazilians who had COVID-19 last year. They found that the effectiveness of their antibodies dropped sixfold against P.1 compared with other coronaviruses. That drop might mean that at least some people would be vulnerable to new infections from P.1.

“There seems to be an increasing body of evidence that suggests that most of the cases associated with the second wave are indeed sort of reinfections,” Faria said.

Faria and other researchers are now looking across Brazil to observe P.1’s spread. Dr. Ester Sabino, an infectious disease expert at the University of São Paulo School of Medicine, said that one of the new outbreaks arose in Araraquara, a Brazilian city of 223,000 people that did not have high rates of COVID-19 before P.1 arrived.

If people in Araraquara did not have high levels of antibodies before P.1’s arrivals, she said, that suggests that the variant may be able to spread in places without Manaus’ extreme history. “This might happen in any other place,” she said.

Michael Worobey, a virus expert at the University of Arizona who was not involved in the research, said it was time to pay attention to P.1 in the United States. He expected it would become more common in the United States, although it would have to compete with B.1.1.7, which may soon become the predominant variant in much of the nation.

“At the very least, it’s going to be one of the contenders,” Worobey said.

In their experiments, Faria and his colleagues also tested antibodies from eight people who received CoronaVac, a Chinese-made vaccine that has been used in Brazil. They found that the vaccine-generated antibodies were less effective at stopping the P.1 variant than other types.

Faria cautioned that these results, derived from cells in test tubes, don’t necessarily mean that vaccines will be less effective at protecting real people from P.1. Vaccines may very well provide strong protection from P.1 even if the antibodies they generate aren’t quite as potent. And even if the variant manages to infect vaccinated people, they will likely remain shielded from a severe bout of COVID-19.

For Sabino, the ultimate importance of P.1 is the threat that concerning variants pose when they can pop up anywhere in the world.

“It’s just a matter of time and chance,” she said.

In just a matter of weeks, two variants of the coronavirus have become so familiar that you can hear their inscrutable alphanumeric names regularly uttered on television news.

In just a matter of weeks, two variants of the coronavirus have become so familiar that you can hear their inscrutable alphanumeric names regularly uttered on television news. B.1.1.7, first identified in Britain, has demonstrated the power to spread far and fast. In South Africa, a mutant called B.1.351 can dodge human antibodies, blunting the effectiveness of some vaccines. Scientists have also had their eye on a third concerning variant that arose in Brazil, called P.1. Research had been slower on P.1 since its discovery in late December, leaving scientists unsure of just how much to worry about it. “I’ve been holding my breath,” said Bronwyn MacInnis, a public health researcher at the Broad Institute. Now three studies offer a sobering history of P.1’s meteoric rise in the Amazonian city of Manaus. It likely arose there in November and then fueled a record-breaking spike of coronavirus cases. It came to dominate the city due in part to increased contagiousness, the research found. But it also gained the ability to infect some people who had immunity from previous bouts of COVID-19. And laboratory experiments suggest that P.1 could weaken the protective effect of a Chinese vaccine now in use in Brazil. The new studies have yet to be published in scientific journals. Their authors caution that findings on cells in laboratories do not always translate to the real world, and they’ve only begun to understand P.1’s behaviour. “The findings apply to Manaus, but I don’t know if they apply to other places,” said Nuno Faria, a virus expert at Imperial College London who helped lead much of the new research. But even with the mysteries that remain around P.1, experts said it is a variant to take seriously. “It’s right to be worried about P.1, and this data gives us the reason why,” said William Hanage, a public health researcher at the Harvard T.H. Chan School of Public Health. P.1 is now spreading across the rest of Brazil and has been found in 24 other countries. In the United States, the Centers for Disease Control and Prevention has recorded six cases in five states: Alaska, Florida, Maryland, Minnesota and Oklahoma. To reduce the risks of P.1 outbreaks and reinfections, Faria said it was important to double down on every measure we have to slow the spread of the coronavirus. Masks and social distancing can work against P.1. And vaccination can help drive down its transmission and protect those who do get infected from severe disease. “The ultimate message is that you need to step up all the vaccination efforts as soon as possible,” he said. “You need to be one step ahead of the virus.” Faria and his colleagues started tracking the coronavirus when it exploded in Brazil last spring. Manaus, a city of 2 million in the Brazilian Amazon, was hit particularly hard. At its springtime peak, the cemeteries of Manaus were overwhelmed by the bodies of the dead. But after a peak in late April, Manaus seemed to have gotten past the worst of the pandemic. Some scientists thought that the drop meant Manaus had gained herd immunity. Faria and his colleagues looked for coronavirus antibodies in samples from a Manaus blood bank in June and October. They determined that roughly three-quarters of the residents of Manaus had been infected. But near the end of 2020, new cases began surging again. “There were actually far more cases than in the previous peak of cases, which had been in late April,” Faria said. “And that was very puzzling to us.” Faria and his colleagues wondered if new variants might be partly to blame for the resurgence. In Britain, researchers were finding that B.1.1.7 was surging across the country. To search for variants, Faria and his colleagues started a new genome sequencing effort in the city. While B.1.1.7 had arrived in other parts of Brazil, they didn’t find it in Manaus. Instead, they found a variant no one had seen before. Many variants in their samples shared a set of 21 mutations not seen in other viruses circulating in Brazil. Faria sent a text message to a colleague: “I think I’m looking at something really strange, and I’m quite worried about this.” A few mutations, in particular, worried him, because scientists had already found them in either B.1.1.7 or B.1.351. Experiments suggested that some of the mutations might make the variants better able to infect cells. Other mutations let them evade antibodies from previous infections or produced by vaccines. As Faria and his colleagues analyzed their results, researchers in Japan were making a similar discovery. Four tourists returning home from a trip to the Amazon on Jan. 4 tested positive for the coronavirus. Genome sequencing revealed the same set of mutations Faria and his colleagues were seeing in Brazil. Faria and his colleagues posted a description of P.1 on an online virology forum on Jan. 12. They then investigated why P.1 was so common. Its mutations may have made it more contagious, or it might have been lucky. By sheer chance, the variant might have shown up in Manaus just as the city was getting more relaxed about public health measures. It was also possible that P.1 became common because it could reinfect people. Normally, coronavirus reinfections are rare, because the antibodies produced by the body after infection are potent for months. But it was possible that P.1 carried mutations that made it harder for those antibodies to latch onto it, allowing it to slip into cells and cause new infections. The researchers tested these possibilities by tracking P.1 from its earliest samples in December. By early January, it made up 87% of samples. By February it had taken over completely. Combining the data from genomes, antibodies and medical records in Manaus, the researchers concluded that P.1 conquered the city thanks not to luck but biology: Its mutations helped it spread. Like B.1.1.7, it can infect more people, on average, than other variants can. They estimate it is somewhere between 1.4 and 2.2 times more transmissible than other lineages of coronaviruses. But it also gets an edge from mutations that let it escape antibodies from other coronaviruses. They estimate that in 100 people who were infected in Manaus last year, somewhere between 25 and 61 of them may have been reinfected by P.1. The researchers found support for this conclusion in an experiment in which they mixed P.1 viruses with antibodies from Brazilians who had COVID-19 last year. They found that the effectiveness of their antibodies dropped sixfold against P.1 compared with other coronaviruses. That drop might mean that at least some people would be vulnerable to new infections from P.1. “There seems to be an increasing body of evidence that suggests that most of the cases associated with the second wave are indeed sort of reinfections,” Faria said. Faria and other researchers are now looking across Brazil to observe P.1’s spread. Dr. Ester Sabino, an infectious disease expert at the University of São Paulo School of Medicine, said that one of the new outbreaks arose in Araraquara, a Brazilian city of 223,000 people that did not have high rates of COVID-19 before P.1 arrived. If people in Araraquara did not have high levels of antibodies before P.1’s arrivals, she said, that suggests that the variant may be able to spread in places without Manaus’ extreme history. “This might happen in any other place,” she said. Michael Worobey, a virus expert at the University of Arizona who was not involved in the research, said it was time to pay attention to P.1 in the United States. He expected it would become more common in the United States, although it would have to compete with B.1.1.7, which may soon become the predominant variant in much of the nation. “At the very least, it’s going to be one of the contenders,” Worobey said. In their experiments, Faria and his colleagues also tested antibodies from eight people who received CoronaVac, a Chinese-made vaccine that has been used in Brazil. They found that the vaccine-generated antibodies were less effective at stopping the P.1 variant than other types. Faria cautioned that these results, derived from cells in test tubes, don’t necessarily mean that vaccines will be less effective at protecting real people from P.1. Vaccines may very well provide strong protection from P.1 even if the antibodies they generate aren’t quite as potent. And even if the variant manages to infect vaccinated people, they will likely remain shielded from a severe bout of COVID-19. For Sabino, the ultimate importance of P.1 is the threat that concerning variants pose when they can pop up anywhere in the world. “It’s just a matter of time and chance,” she said.

Virus variant in Brazil infected many who had already recovered from Covid-19