lunes, 20 de diciembre de 2021

lunes, diciembre 20, 2021

Fresh Insights on the New Variant

The Omicron Wave Hits Europe

The latest variant of the coronavirus is rapidly spreading across Europe, and health-care systems in some countries are already overwhelmed. Fears are growing that Omicron will unleash the worst wave yet seen in the pandemic.

By Rafaela von Bredow und Veronika Hackenbroch

An intensive care nurse in Magdeburg, Germany. A new wave of hospitalizations could be coming. Foto: RONNY HARTMANN / AFP


On Fridays, the popular seafood restaurant Louise, located right on the Oslo waterfront, turns into a nightclub – as it did on a recent, ice-cold evening in November. 

Employees of the company Scatec, which specializes in renewable energies, began arriving early in the evening, ultimately swelling to a crowd of 119 people. 

They were all looking forward to the company Christmas party.

"Everyone was happy to finally eat together again, drink wine and dance," says Tine Ravlo, a doctor who is also the public health official in charge of the Oslo district where Louise is located. 

And then, she says, there was the cold. 

"Nobody wanted to go outside or open a window."

And everyone felt safe, says Ravlo, because they had all been completely vaccinated and presented negative PCR or rapid antigen tests upon arrival. "

At 10:30 p.m., the doors were opened between the room where the company party was taking place and the rest of the restaurant, which was open to the public," says Ravlo. 

"Everyone mixed together."

And they danced. 

"You breathe more heavily and, when the music is loud and you’ve had a bit to drink, you speak louder too."

"It Will Soon Dominate"

The Christmas party in Oslo turned into a superspreader event. 

Ultimately, Ravlo and her team counted 145 infections, including 81 of the 119 Scatec employees along with 64 other restaurant guests.

The Louise restaurant in Oslo: 145 new infections after a Christmas party. Foto: Ole Berg-Rusten / dpa


It was the same Friday that the World Health Organization christened the new coronavirus variant "Omicron," and declared it to be a "variant of concern."

"The fact that Omicron is here in Oslo was quite a shock for me," says Ravlo. 

"We had only even learned of the variant’s existence just a few days before."

It later emerged that a Scatec employee had returned only two days before the Christmas party from the company’s office in Cape Town. 

Several other colleagues had also been in South Africa in the weeks leading up to the festivities. 

But because their tests also came back negative, it seems unlikely that they brought Omicron into the company.

Now, three weeks after the Christmas party, case numbers are exploding in Norway, and the number of people ending up in the hospital is also on the rise. 

The government has imposed strict measures.

"The Omicron variant is becoming established in Norway and will soon dominate," reads the most recent alert from the Norwegian Institute of Public Health. 

At the beginning of next year, experts believe a worst-case scenario could see up to 300,000 new infections per day and 200 people having to be hospitalized – in a country that only has just over 5 million people. 

That is, if "the measures do not slow the epidemic significantly," the alert continues.

By the time WHO christened the new variant on that Friday in November, it had already spread to various regions of the world. 

And the fears of virologists given the numerous mutations displayed by the new variant have been largely confirmed since then: Omicron is far more infectious than Delta, and it is also able to infect those who are fully vaccinated, and even those who have received their booster.

It is almost as though a completely new pandemic has been unleashed – a turbo-contagion. 

In Norway, Denmark and Britain, the effects this virus can have on people and health-care systems are already painfully clear. 

The question, though, remains whether and when the lessons from these countries can be applied to Germany and the rest of the world.

"With Omicron, the cards in this pandemic are being re-shuffled – unfortunately in favor of the virus," says Melanie Brinkmann, a prominent virologist and member of the German government’s new expert council, which met for the first time on Tuesday and will be submitting a report on the Omicron threat by Christmas. 

The variant, says the virologist, is spreading "with a tremendous dynamic."

Michael Meyer-Hermann, a mathematical modeler at the Helmholtz Center for Infection Research: "Omicron could be responsible for half the cases in Germany within two-and-a-half weeks." Foto: Angelina Vernetti


Michael Meyer-Hermann, a physicist and mathematical modeler at the Helmholtz Center for Infection Research, is also concerned. 

"Omicron has so much speed," he says, "that the variant could be responsible for half the cases in Germany within two-and-a-half weeks." 

That, though, he continues, is a rather pessimistic forecast and should be approached with care given the lack of data available.

In Britain, Omicron is already making itself felt in the form of record daily infection numbers. 

On Thursday, officials counted 88,000 new infections, more than ever before in the country. 

By April, according to model calculations, the variant could have infected half of the country.

Already, it is clear that extremely high case numbers will mean the country is likely to run out of corona tests. 

Should that happen, it will no longer be possible to calculate the precise infection rate, meaning that the only tool for monitoring the spread of the virus will be hospital admittances. 

"It will be a bit like trying to navigate a racecourse by looking in a rearview mirror," London-based mathematician and epidemiologist Adam Kucharski tweeted on Wednesday.

"Cases of Omicron are doubling in less than two days," says Deepti Gurdasani, an epidemiologist at Queen Mary University in London. 

As such, she is concerned about a "huge surge by Christmas and New Year’s, with considerable pressure on health services." 

Many, she believes, aren’t yet clear about what that means. 

"I don’t think people are perhaps as concerned as they should be."



Modelling performed by Britain’s Scientific Advisory Group for Emergencies (SAGE), says Gurdasani, indicate that even in the best-case scenario, twice to three times as many people will end up in the hospital because of COVID-19 than today. 

That translates to between 1,700 and 2,500 per day.

Like so many European countries, Britain identified its first Omicron case in late November. 

Since then, especially in London, the new variant has overtaken the Delta variant.

Denmark also expects that the Omicron variant will become the dominant variant in the country in the coming days. 

"We have seen a rapid increase in Omicron cases," says epidemiologist Troels Lillebæk from the University of Copenhagen, who is also chair of the Danish SARS-CoV-2 variant assessment committee. 

Case numbers doubled every two days in the early phase.

Every Dane, says Lillebæk, receives an identification number at birth, to which all new COVID-19 cases are assigned. 

"We will soon have an extremely clear picture of Omicron," he says. 

At the moment, though, he continues, data is coming in so quickly that it is impossible to keep up.

Indeed, the situation in the country has become so dramatic that Danish Prime Minister Mette Frederiksen on Friday ordered the closure of theaters, cinemas, concert halls, amusement parks, museums and art galleries. 

Stores and restaurants will also be required to limit the number of visitors. 

Before going into effect, the order must first be approved by parliament, which is meeting on Friday afternoon.

Lillebæk believes that the Omicron spike currently taking place in Denmark is also happening in many other European countries, even if they may not yet be fully aware of it. 

"There is no reason to assume that Denmark has particularly many Omicron cases compared to other European countries, although there might be regional differences," he says. 

"We don't have any special relations with South Africa. 

In that regard, we are just an average country."

Denmark, though, has a particularly good surveillance program for novel variants and performs an extremely high number of tests, including fully 200,000 PCR tests per day. 

Relative to the population, that is about 10-times the rate of testing in Germany. 

And that, believes Lillebæk, is why the Omicron rise has become apparent earlier in Denmark. 

"You only find what you are looking for, especially in the beginning," he says.

Two Dangerous Characteristics

It is primarily two characteristics that make Omicron so dangerous. 

For one, it is probably more contagious than any variant that has preceded it. 

In addition, Omicron is a so-called escape variant, meaning it can sidestep parts of our immune defenses. 

Those who have recovered from COVID-19 or have been vaccinated possess antibodies that, in cases of infection, will recognize the intruder and deactivate it. 

Omicron, though, has disguised itself. 

Experiments have revealed that the ability of antibodies to neutralize this variant is reduced about 40-fold. 

That also explains why currently available vaccines are much less effective against the new variant than they were against previous variants. 

Breakthrough infections are far more common than they were with Delta.

Nevertheless, initial data from South Africa provides some cause for optimism. 

According to an analysis performed by Discovery Health, the country’s largest health insurance provider, the risk of hospitalization with the new variant is almost 30 percent lower than in the first wave. 

Does that mean that Omicron is perhaps milder and less dangerous than previous variants? 

Could we perhaps allow Omicron to spread through the population like a seasonal flu without overwhelming our health-care system, thus achieving widespread immunity, even among the unvaccinated?

Experts warn unanimously and urgently against such an interpretation. 

In a situation where there is a gigantic number of infections, even a small percentage of seriously ill patients would, in absolute terms, be enough to easily overwhelm the intensive care units. 

The variant’s elevated contagiousness, in other words, is enough to counteract the fact that it causes less severe symptoms in many patients.

Furthermore, the numbers from South Africa cannot be applied one-to-one to other countries. 

Previous coronavirus variants – Alpha, Beta and Delta – raced through a huge share of the country’s population, such that, in combination with those who have been vaccinated, most people in the country have a certain level of immunity, and thus a degree of protection against the most serious symptoms. 

Furthermore, the population is much younger, which also helps.

Thus far, says virologist Christian Drosten, Germany’s leading voice on the pandemic and also a member of the government’s new expert council, only "conjectures are possible" regarding the seriousness of the symptoms caused by Omicron. 

"Based on the indirect data available," he says, he believes there will be "only a slight reduction in case severity."

Virologist Christian Drosten: "The apparent reduction in disease severity is merely a consequence of population immunity.” Foto: Marzena Skubatz / laif


One peculiarity in particular has grabbed Drosten’s attention in this regard: the fact that many children in South Africa under the age of five have had to be hospitalized with an Omicron infection. 

Drosten believes that might be because young children have not yet reached "group immunity through widespread infection as is the case in other age groups."

Should this assumption prove accurate, then the Omicron wave in young children would reflect that in those who have no immunity. 

That would then mean that the Omicron variant isn’t necessarily less dangerous, "but that the apparent reduction in disease severity is merely a consequence of population immunity."

In other words, Omicron could have just as dangerous an effect on the unvaccinated as the variants that have come before.

The Risk of Personnel Shortages

"It will be critical to break the Delta wave and empty out the hospitals before the Omicron wave crashes over us," says Meyer-Hermann, the physicist and mathematical modeler at the Helmholtz Center for Infection Research. 

The measures currently in place are "adequate for slowing the Delta wave, but not for preventing the Omicron wave."

Still, the currently imposed measures could slow the pace of Omicron’s spread, says Drosten. 

He assumes that case numbers here will take longer to double than has been the case in Britain. "

Around four days," he believes. 

And Danish epidemiologist Lillebæk says that there is, from his perspective, one thing that Germany is doing right: "I was traveling in your country," he says. 

"You are really good at wearing masks."

Nevertheless, Drosten believes that there will be an extremely high number of cases by the middle of January, "insofar as new measures to prevent social contact aren’t enacted before then."

Nobody knows at the moment what share of the newly infected will end up in the hospital. 

In Denmark, the hospitalization rate of Omicron patients is only around 0.6 percent – which translates to six out of every 1,000 cases. 

But that could change rapidly, warns Lillebæk. 

"In our worst-case scenario from this Monday, which I hope doesn't happen, we expect around 500 hospital admissions per day around New Year's Eve."

When extrapolated to Germany, that rate would result in 7,000 hospitalizations due to COVID-19 per day.

But even if those numbers are not reached, Omicron could lead to serious problems, says Lillebæk. 

"We are worried that perhaps a great many doctors and nurses will have to be quarantined because of infection, even if they are not seriously ill," he says. 

That could lead to bottlenecks in patient care, he worries. 

Extremely high case numbers could also create problems in other areas of life, such as schools, urban transportation systems, garbage collection and factories. 

"You have to act quickly," says Lillebæk. 

"The longer you wait, the greater the risk of a full lockdown is likely to be."

In the fight against Omicron and other, future variants, Drosten believes it will be decisive to vaccinate as many of the unvaccinated as rapidly as possible. 

"Despite the appearance of Delta and Omicron, I don’t believe that similarly large evolutionary leaps will be relevant once we have reached a significant level of immunity in the population," he says. 

That is why it is vital to close the vaccination gap, he says, adding that doing so "should have a higher priority than refreshing vaccination protections." 

Boosters can significantly weaken the effects of a Delta infection and, as seen in Israel, help break a wave. 

That is because with Delta, booster shots can protect patients from becoming infected in the first place.

With the Omicron variant, though, this advantage largely falls away, Drosten says. 

"We are regularly seeing boostered Omicron patients who have an extremely high viral load in the first days of an infection. 

That means that with Omicron, those who have received their booster also contribute significantly to the spread of the virus." 

Still, he adds, even with Omicron, booster shots play a role in mitigating symptoms and shortening the illness."

"A variant like Omicron will change the course of the pandemic," says the London-based epidemiologist Deepti Gurdasani. 

"I seriously hope that countries learn from the rapid evolution of this virus and stop saying we can live with this. 

We can’t, without mass suffering, disruption and death." 

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