A long line of people is seen outside a hospital as they wait for a COVID-19 test. Share on Pinterest
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  • Many people are experiencing milder symptoms during the current wave, but with so many cases, hospitals are still under pressure.
  • A recent preprint of a medical study found that the risks of emergency department visits, hospitalizations, admissions to the ICU, and mechanical ventilation were two to six times higher during the Delta wave than the Omicron wave.
  • Hospital data from New York City shows that unvaccinated people are much more likely to end up in the hospital than vaccinated people, even during the Omicron surge.

As the Omicron variant of the coronavirus continues to surge throughout the United States, doctors are reporting that this wave of infections is presenting differently in hospitals.

Overall, there are signs that this wave is less severe than the Delta variant one.

This lower severity, of course, is on average. There are still people getting sick enough to end up in the hospital or in the intensive care unit (ICU).

In addition, with a sharp increase in cases in recent weeks, many parts of the country are seeing an increase in hospitalizations.

This is having ripple effects on the healthcare system. It’s straining an already exhausted workforce, causing cancelations of nonurgent procedures, and increasing the chances that people at risk of severe COVID-19 will contract infections.

“We are seeing cases rise quickly, but less need for hospital care and less need for respiratory support than previous surges,” said Sandra Kane-Gill, PharmD, president-elect of the Society of Critical Care Medicine.

However, “less severe cases from Omicron does not mean that hospitals and ICUs are not busy, because the sheer volume of infections is creating stress on hospitals… Also, emergency departments are overwhelmed with the need for [COVID-19] testing,” she said.

This pattern fits with emerging data that Omicron may cause less severe illness than variants that have come before.

One preprint study in mice and hamsters found that animals infected with Omicron had less lung damage, lower weight loss, and reduced risk of dying than animals infected with earlier variants.

Other preprint studies in mice and hamsters have found similar results.

In addition, a recent preprint found that the risks of emergency department visits, hospitalizations, admissions to the ICU, and mechanical ventilation were two to six times higher during the Delta wave than the Omicron wave.

Still, it’s too early to know for certain if Omicron causes less severe illness.

Scientists need to take into account other factors that can impact the severity of illness, such as underlying medical conditions, access to treatments, and how overwhelmed a hospital is at the time. These kinds of analyses take time.

Kane-Gill said the appearance of Omicron as less severe may also be influenced by the fact that many people have immunity from vaccination or prior infection.

However, one thing that’s clear is that “the number of unvaccinated people requiring hospitalization and critical care from the virus outweighs the vaccinated people,” she said.

“Immunocompromised people are also at greater risk for hospitalization and critical illness,” Kane-Gill added.

Hospital data from New York City and other cities show that unvaccinated people are much more likely to end up in the hospital than vaccinated people, even during the Omicron surge.

Given Omicron’s ability to overcome the immune protection against infection offered by one or two doses of a COVID-19 vaccine (as well as by prior infection), Kane-Gill recommends that everyone get a booster dose as soon as they are eligible.

While the risk of vaccinated people contracting an infection is higher with Omicron than with Delta or earlier variants, the COVID-19 vaccines continue to offer strong protection against severe illness.

Dr. M. Kit Delgado, an assistant professor in emergency medicine at Penn Presbyterian Medical Center, wrote on Twitter on Jan. 2 that he has hardly seen any patients who have gotten their booster, because if they developed COVID-19, “they’re likely at home doing fine or having regular cold/flu-like symptoms.”

However, COVID-19 patients who are vaccinated but unboosted were “wiped out, dehydrated, [and] febrile.” Those over age 55 were often admitted to the hospital overnight for intravenous fluids, he said, but usually went home within a day or two.

Finally, the unvaccinated patients he has seen “are the folks that get sick and had to be hospitalized because they need oxygen, some even younger than me,” Delgado wrote.

Because hospitalizations lag behind cases, and deaths behind hospitalizations, Kane-Gill said we will gain a better sense of the severity of the Omicron wave in the United States over the next few weeks.

But in the United Kingdom, which is carefully tracking Omicron, there are positive signs heading into this new year.

Since mid-December, the United Kingdom has seen a sharp decline in the share of patients with COVID-19 on a ventilator. London’s ICU admissions have also dropped off in recent weeks and are currently much lower than last winter’s coronavirus surge.

However, the United Kingdom and United States have different vaccination and booster rates, so they may experience the Omicron surge differently.

Still, even with a smaller percentage of people getting severely ill during the Omicron wave, a large number of cases over a short time can lead to a spike in people being hospitalized or admitted to the ICU.

“Omicron is certainly resulting in a lower hospitalization rate, or risk of hospitalization, but Omicron is not mild. Omicron is not the common cold,” Maria Van Kerkhove, PhD, COVID-19 technical lead for the World Health Organization, told the BBC.

“Omicron and Delta are infecting individuals, they’re putting people in hospitals. And if you have huge numbers of cases, you will have increased hospitalization,” she said.

In the United States, ICU admissions in several states are approaching the level of their previous peak.

In addition, said Kerkhove, “this virus, Omicron, will reach vulnerable populations. It will reach older populations. And we will see increasing deaths among those individuals.”

Dr. Craig Spencer, an associate professor in emergency medicine at Columbia University Medical Center, wrote on Twitter on Jan. 3 that for some people, COVID-19 can also “topple a delicate balance of an underlying illness.”

“Diabetics in whom COVID precipitated diabetic ketoacidosis, a serious and life-threatening condition. Older folks sick with COVID just too weak to get out of bed. Can’t walk. So can’t leave the hospital,” he wrote.

This recent surge of hospitalizations is also coming on the heels of the Delta wave, which has increased pressure on a healthcare system that has been dealing with the pandemic for almost 2 years.

“Healthcare professionals are already experiencing burnout and exhaustion, and some even left their careers because of it, causing a strain on the workforce,” said Kane-Gill.

In addition, Omicron’s high transmissibility means many healthcare workers will contract coronavirus infections and not be able to work until their isolation period ends.

“In the previous surges, we appeared more worried about supplies like ventilators,” said Kane-Gill. “Now with this surge, there is a greater concern for staffing shortages.”