Why Omicron is less dangerous than the Delta variant but more transmissable

Omicron is between two and four times more contagious than Delta and is better at evading antibodies triggered by vaccines, which is why it’s causing more infections

By Joanne Savage
Friday, 4th February 2022, 1:47 pm
Omicron appears unable to infect lung cells as efficiently as the Delta variant
Omicron appears unable to infect lung cells as efficiently as the Delta variant

With dozens of mutations, Omicron is different from the previously dominant Delta variant in significant ways, which means that, after two years of getting a handle on how to manage risk, you might need to shift at least some of your behaviours.

Among the changes, Omicron is more transmissible and better at evading existing antibodies.

“To me, the biggest shift, the most shocking thing, is how incredibly infectious this thing is. I have never seen anything so infectious in my life,” said Carlos del Rio, an epidemiologist and infectious diseases specialist at Emory University in Atlanta, Georgia, who spoke to nationalgeographic.com.

Sign up to our public interest bulletins - get the latest news on the Coronavirus

At the same time, Omicron causes different symptoms and seems to lead to less severe disease.

Still, different strains of SARS-CoV-2 share important similarities, and much of the basic public health advice — get vaccinated, wear a mask — remains the same.

HERE’S WHAT THE LATEST RESEARCH SAYS ABOUT STAYING SAFE IN THE AGE OF OMICRON

Multiple lines of evidence from various parts of the world suggest that the Omicron variant causes a less severe form of Covid-19.

In South Africa, where Omicron was first detected in November 2021, a private health insurance administrator reported in mid-December that adults with Omicron were 29 percent less likely to be hospitalised, compared with adults infected several months earlier.

Here in the UK. the rate of hospital admission among people who went to the emergency room with Omicron was a third of what it was for Delta, according to a summary of research from the UK Health Security Agency released on December 31, 2021.

As of early January, US adults with Omicron were less than half as likely to visit the emergency room, be hospitalised, or be put on a ventilator, according to preliminary work by researchers from Case Western Reserve University School of Medicine.

Their study examines data for more than 14,000 patients and accounts for their vaccination status and any pre-existing conditions.

A shift in symptoms reflects those trends, del Rio said.

In the hospital, patients are showing up less often with pneumonia-like symptoms and hyperactive immune systems, as seen in previous waves.

Instead, they’re more often presenting with congestion and scratchy throats.

“In Omicron, the symptoms are more like a head cold,” he says.

A shift in symptoms reflects those trends, del Rio says. In the hospital, patients are showing up less often with pneumonia-like symptoms and hyperactive immune systems, as seen in previous waves.

Instead, they’re more often presenting with congestion and scratchy throats.

“In Omicron, the symptoms are more like a head cold,” he said.

Omicron appears to be less severe than Delta in all age groups, even in adults older than 65 and in children too young to be vaccinated, according to the Case Western study.

Still, as with other health issues, age remains a factor, del Rio says.

“For any disease, if you’re older, you’re going to do a lot worse,” he says.

People with underlying conditions or compromised immune systems also remain more vulnerable, as do people who are unvaccinated.

Although current vaccines are less effective at preventing symptoms from Omicron than from Delta, the UK report found that people who were fully boosted were up to 88 percent less likely to be hospitalised with Omicron compared with unvaccinated people.

Hospitals around the country report that unvaccinated patients make up the majority of people now in intensive care units, globally.

Regardless of age or health status, people infected with Omicron can feel terrible even if they don’t have to go to the hospital, and the variant continues to hospitalise and kill many people, emphasised Tedros Adhanom Ghebreyesus, director-general of the World Health Organization, at a virtual press conference last month.

WHY IS OMICRON DANGEROUS IF IT’S LESS SEVERE THAN DELTA?

Omicron is between two and four times more contagious than Delta, according to a Danish study.

It’s also better at evading the antibodies triggered by vaccines, which is why it’s causing more breakthrough infections.

As a result, more people are getting sick and showing up at hospitals, where more staff are calling in sick, del Rio added.

Omicron appears unable to infect lung cells as efficiently, which in turn makes it less damaging and the symptoms less severe.

But in the upper respiratory tract, which includes the nose and sinuses, Omicron seems to replicate more than a hundred times faster than Delta.

A message from the Editor:

Thank you for reading this story on our website. While I have your attention, I also have an important request to make of you.

With the coronavirus lockdown having a major impact on many of our advertisers - and consequently the revenue we receive - we are more reliant than ever on you taking out a digital subscription.

Subscribe to newsletter.co.uk and enjoy unlimited access to the best Northern Ireland and UK news and information online and on our app. With a digital subscription, you can read more than 5 articles, see fewer ads, enjoy faster load times, and get access to exclusive newsletters and content. Visit https://www.newsletter.co.uk/subscriptions now to sign up.

Our journalism costs money and we rely on advertising, print and digital revenues to help to support them. By supporting us, we are able to support you in providing trusted, fact-checked content for this website.

Ben Lowry

Editor