Could humanity break with Omicron?



In the weeks since the Omicron variant announced its presence, scientists have been preparing for another unpleasant surprise of a virus that has killed more than 5.3 million and made hundreds of millions more sick. . But as they study the preliminary data on the strain, they are cautiously considering an unexpected possibility: that with Omicron, the coronavirus may finally be cutting humanity a little.

There are still many reasons to worry: Omicron has spread to at least 77 countries, found its way to at least 35 U.S. states, and is on track to become the dominant strain in Europe in mid-January.

According to a series of laboratory tests and population studies in South Africa, where Omicron is on the rise, the variant has profoundly curtailed the ability of the Pfizer-BioNTech vaccine to prevent further infections. And compared to Delta and other variants, they are much more likely to reinfect people who have already recovered from a COVID-19 attack.

At the same time, there are intriguing indications that with Omicron, the coronavirus has taken a slower turn.

South African adults infected during the rise in Omicron were 29% less likely to be hospitalized with COVID-19 compared to their compatriots who became ill during the first wave of cases in the summer of 2020. And compared to previous waves, adults hospitalized with Omicron were less likely to be admitted to the intensive care unit or need expensive and intrusive levels of hospital care.

All of this suggests that in an Omicron-dominated world, the proportion of infected people who die could fall well below the 1% to 2% mortality rate that has prevailed for much of the pandemic. It could also slow down the number of hospitalizations that have strained health care systems and depleted medical professionals.

If the cases tend to be milder and COVID-19 vaccines could still protect the most vulnerable from death, a more gentle and gentle Omicron, even a highly contagious one, could be the rest that health officials and scientists were waiting.

“Is this the end of the pandemic?” Pieter Streicher, coronavirus analyst at the University of Johannesburg, he asked on Twitter.

In the South African province of Gauteng, where the first major increase in Omicron infections was observed, new infections linked to the variant reached a peak that was previously only reached by Delta, and reached much faster. However, there are hospitalizations projected it was 25 times lower than would be expected with such a high infection rate, Streicher noted.

Mortality rates for COVID-19 in South Africa have also fallen sharply despite the Omicron wave. If there is no massive increase in hospitalizations or deaths in the next two to three weeks, this “could mark [a] turning point [the] pandemic “, Dr. Shabir Madhi, an infectious disease expert at the University of the Witwatersrand, wrote on Twitter.

A variant that combines high transmissibility with very low virulence would be welcomed by many scientists. If an Omicron infection is unlikely to make a patient seriously ill, but leaves some immunity in their path, it could act as a “natural vaccine,” said Dr. Bruce Walker, immunologist and founding director of the Institute. Ragon of Cambridge, Massachusetts. .

It could be the beginning of the end.

For now, it’s just a glimmer of hope, and nearly two years of experience have made scientists and health officials wary of taking good news. But among evolutionary microbiologists, epidemiologists, and biologists who have wondered how the pandemic will end, a host of mutations that impede the virus’s ability to get sick while increasing its transmissibility has long been a favorite scenario.

Under these circumstances, the virus becomes an endemic “annoying virus”, joining four other coronaviruses that have settled among humans and are the leading causes of the common cold. They have ensured their survival by producing mild illnesses and leaving only a little immunity in their path. Once lodged in the upper airways of the respiratory tract, the kidneys and cough they generate ensure that infectious particles escape into the air and are left behind on the surfaces. But the mildness of these symptoms allows infected hosts to go to school, work, supermarkets, gyms, and movie theaters, to better spread their germs.

People exposed to these viruses throughout their lives build a natural immunity. But the limited immunity of the majority of the population ensures that the viruses have a large number of potential hosts year after year. The battle between pathogens and humanity is at a standstill.

“This is what we all look forward to,” said Dr. Stanley Perlman, a virologist at the University of Iowa who has studied coronaviruses for decades.

But he said it’s too early to tell if this hopeful scenario will come out with Omicron.

“There have been so many twists and turns” during the two years of SARS-CoV-2 riots between humans, Perlman said. “We thought Delta was the end. We thought, ‘This is going to stay with us,’ and now it doesn’t seem right. But we all have hope.

Others expressed doubt more quickly than acknowledging hope.

There are big differences between South Africa and the United States that make it risky to rely too much on the first few data. Mild COVID-19 is the overwhelming standard in South Africa because 73% of South Africans are under the age of 40 (compared to 52% in the US), an age group in which the risk of serious illness they are low. Only 16% of South Africans are over 60 (compared to 23% here).

In addition, South Africa’s three waves of infections and its delay in access to vaccines have produced a population that has been infected and reinfected many times. The resulting immunity is likely to make cases milder in general.

If Omicron causes a milder illness, this is only a degree improvement. If the new variant only causes 10% of those infected to be severely ill with COVID-19, halving its virulence, this would appear to be a great victory for humans.

But this gift could be erased with a big enough leap in the propagation capacity of the variant. If Omicron is twice as transmissible as Delta, even a 50% reduction in virulence will be a wash. And if it is more than twice as contagious, hospitals will start to fill up quickly.

“Even if it is milder, and I wouldn’t rule it out, the growth rate of Omicron, the large number of infections it is causing and the speed with which it is increasing means that we are a long way from the end of the pandemic.” he said. William Hanage, epidemiologist at Harvard School of Public Health.

If Omicron also erodes vaccine protection and easily reinfects COVID-19 survivors, this could be another point in favor of the virus.

Preliminary reports from South Africa suggest that in the Omicron era, two doses of the Pfizer vaccine provided only 33% protection against infection and 70% protection against hospitalization, below 80%. and 93% in previous months.

Even with reduced virulence, figures like these could return millions of vaccinated people to the group of those vulnerable to serious illness. This would give the virus a chance to regain any benefits it may have given humans.

While scientists cling to hope, they are well aware of the genetic curves that the coronavirus could still launch. Even if it slows down its deadly paths and settles for a long stay, its error-prone replication machinery will continue to cause mutations. And if Omicron is as transmissible as it seems to be, it will have a good chance of doing so.

The virus could give humanity a small genetic favor today and recover it tomorrow. Hanage still doesn’t breathe a sigh of relief.

“Only a fool would bet on Mother Nature,” he said.

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