Coronavirus: Is the Omicron variant really less dangerous than Delta?

Among the various distinguishing features is the fact that the Omicron variant is more transmissible and more adept at evading existing antibodies. “For me the most specific and surprising aspect is the very severe infection of this species. I have never seen anything contagious in my life,” says Carlos del Río, an epidemiologist and infectious disease specialist at Emory University in Atlanta, Georgia. At the same time, Omicron causes Various symptoms and a less severe form of the disease.

It remains true that many strains of SARS-CoV-2 have basic similarities, and most public health recommendations (vaccinating and wearing a face mask) still apply. Here’s what the latest preventive research in the era of the Omicron variable tells us.

The numbers of Omicron infections in Italy are very high, but “thanks to the vaccinations, hospitalization less than in the past “as Minister Speranza said.” There is no doubt that by the end of 2022, with the exception of another variable, almost the entire population will meet, for better or worse, with Omicron ”, added Undersecretary of the Ministry of Health Pierpaolo Celeri in the telecast Sunday in.

Is it true that the Omicron variant causes less serious disease than Delta?

Multiple evidence from around the world indicates that the Omicron variant leads to a less severe form of COVID19. In South Africa, where Omicron was first taken in November 2021, a private health insurance official reported in mid-December that adults with the Omicron variant were 29% less likely to be hospitalized than adults who had been infected several months earlier. In the UK, the share of hospitals among patients who arrived in the emergency room due to Omicron was a third of Delta’s, according to a summary of research by the UK Health Safety Agency and published on December 31, 2021.

In early January, less than half of American adults with omicron made it to the emergency room, were hospitalized, or were put on respirators, according to preliminary work developed by researchers from Case Western Reserve University School of Medicine. This study – which has not yet been reviewed – examines data from more than 14,000 patients, taking into account their vaccination status and pre-existing conditions.

The various symptoms detected reflect the above trend, says Del Rio. Few people arrive at the hospital with symptoms similar to those of pneumonia and an overactive immune system, as seen in previous waves; On the contrary, the most common symptoms now are nasal congestion and sore throat. “Omicron’s symptoms are very similar to those of a cold,” Del Rio continues.

Does disease severity change based on age and pre-existing conditions?

The Omicron variant appears to be less severe than Delta in all age groups, including adults over 65 and children for whom a vaccine is not yet available, according to the study. Western case. However, as with other diseases, age is certainly a factor, as del Rio says, “With any disease, older adults have greater difficulties.”

People with diseases or weakened immune systems remain at greater risk, as do those who have not been vaccinated. Although current vaccines are less effective in preventing symptoms of the Delta Omicron variant, the UK report found that those who completed a course of vaccination with Omicron were 88% less likely to be hospitalized, compared to those who had not been vaccinated. State hospitals report that unvaccinated people account for the majority of patients in intensive care.

Tedros Adhanom Ghebreyesus noted in Virtual Press that regardless of age and pathology, people who develop the omicron variant can become severely ill without even ending up in hospital, and in any case, this type of virus continues to cause many of hospitalizations and deaths. Conference last week Director-General of the World Health Organization.

Why is an Omicron variable dangerous if it is less severe than delta?

The Omicron variant is two to four times more contagious than Delta, according to a not-yet-reviewed Danish study, and is better at avoiding vaccine-activated antibodies, which is why it causes more inflammation. breakthrough. As a result, more people get sick and come to hospitals, as there are more and more medical staff at home, del Rio explains.

Micron has 36 mutations in its spike protein, which is the essential part of the virus to “attach” itself to and infect human cells. Although not yet reviewed, more than five studies have been done with small animal models — such as mice and hamsters — and lab cell cultures are beginning to reveal how these mutations alter the way the Omicron variant infects. Cells and multiply, says John Moore, a vaccine researcher and virologist at Weill Cornell Medicine in New York.

In contrast to previous variants, Omicron appears to be less effective in infecting lung cells, and therefore is less dangerous and causes less severe symptoms. Some studies show that the viral load is significantly lower in the lung of rodents infected with Omicron; On the contrary, in the upper respiratory tract, which includes the nose and paranasal sinuses, omicron appears to multiply a hundred times faster than Delta.

This combination of differences (preference for the upper respiratory tract, more effective invasion of the immune system, higher rate of infection) reflects the dynamics of evolution, driving the virus to ensure survival by replication and spread, regardless of incidental effects on guest individuals.

“The virus is not interested in whether the subject is alive or dead, it is interested in replicating itself and being able to pass on to another host,” Moore says. “The goal is to replicate the genome.”

What do these features mean for running quick tests yourself?

All strains of SARS-CoV-2 can infect cells in the mouth, and the Omicron variant can be found in greater quantities than other variants, some early evidence suggests. In a study not yet reviewed, researchers in South Africa tested 382 people with COVID-19 symptoms but not at the hospitalization level, noting that nasal swabs were more accurate in those with delta, while in the case of Omicron saliva tests worked better. .

Other studies also suggest that rapid nasal swab antigen tests may be particularly slow in identifying omicron infection. In a study that has not yet been reviewed, researchers analyzed samples from 30 people who tested positive for COVID-19 in the United States during waves of early December. For the majority of Omicron cases, the PCR test results came in days before the rapid tests. These findings mirror what people write on social media, says study co-author Ann Wylie, a medical microbiologist at Yale School of Public Health de New Haven, in Connecticut.

Jill Weatherhead, an infectious disease expert at Baylor College of Medicine Houston says.

Does a double mask help protect you from microns?

The US Centers for Disease Control and Prevention does not currently recommend the use of double face masks or specific masks. However, other countries, such as Austria, France, Italy and Germany, have updated their guidelines and recommend surgical masks or FFP2 masks. Some US experts also encourage the use of high-quality masks.

One study found that when worn correctly, an FFP2 mask blocks an average of 90% of exhaled particles, while surgical masks block only 74% – which can make a big difference in terms of the spread of the virus between people. In Bangladesh, the use of surgical masks has been boosted, which in some villages has increased from 13% to 42%. The researchers found a similar 11% reduction in COVID-19 symptoms, especially in the older groups. When it comes to cloth masks, the data isn’t uniform, but wearing a cloth mask over a surgical mask can block more than 85% of phlegm particles, according to some research.

Experts recommend choosing a mask based on the situation you are in. In social situations for example, Moore wears a cloth mask with the logo of the football club, Liverpool, on it. On the other hand, when he is at work or in the shops, he prefers the mask which is always of cloth but thicker, which he finds comfortable. On the other hand, Del Rio wears FFP2 when he is with patients. He adds that a mask alone is not enough to defend us from microns. “There is no magic bullet for that, we need to implement a series of preventive measures,” he continues. “Those who have been vaccinated and who also remember and wear a good mask correctly, can also spend a lot of time in social contexts.”

In Italy, wearing an FFP2 mask is currently mandatory Indoors such as movie theaters, public transportation theatres, entertainment venues, live music, and indoor or outdoor sporting events. Instead, surgery is sufficient for the supermarket, at school, or for a walk in the fresh air.

Is it still necessary to disinfect surfaces, keep them spaced out or adopt certain hygiene practices?

Like previous variants, Omicron is also transmitted primarily by air, and experts agree that disinfecting surfaces has no real benefit. “Transportation across surfaces is very rare,” Wiley says. Given the “time, energy, money and resources – even mental – that this activity requires, it is best to devote them to washing hands, social distancing, and wearing a mask.”

Abraar Karan, an infectious disease expert at Stanford University in Palo Alto, California, notes that the two-meter distance indicator also primarily serves as a reminder that proximity to an infected person increases the risk of infection.

“Transport can also happen beyond two metres, that’s for sure,” he says, “but the distance reduces the potential for transmission, because the further away we go, the more the aerosol is diluted.” The risks also depend on the ventilation, the type of masks other people wear, and other factors.

Does the Omicron variant also represent a Long COVID risk?

It’s too soon to know, and it will likely be months before researchers can determine whether or not the Omicron variant may cause symptoms that persist over time, but some experts are hopeful that long-term consequences will be less common. The tendency of the Omicron variant to become unstable in the lungs, and also because the number of people vaccinated continues to rise, which helps prevent infections and lowers the risk of developing a variety of symptoms. “I imagine we will continue to see cases with these symptoms, but as more people get vaccinated, I hope we will see fewer cases of Long-Covid disease,” Willie says.