Omicron cases proving less severe
Hospitals fill up in variant hot spots, but ICUS may not
In hospitals around the country, doctors are taking notice: This wave of COVID19 seems different from the last one.
Once again, as they face the highly contagious omicron variant, medical personnel are exhausted and are contracting the virus themselves.
And the numbers of patients entering hospitals with the variant are surging to staggering levels, filling up badly needed beds, delaying nonemergency procedures and increasing the risk that vulnerable uninfected patients will catch the virus.
But in omicron hot spots from New York to Florida to Texas, a smaller proportion of those patients are landing in intensive care units or requiring mechanical ventilation, doctors said. And many — 50% to 65% of admissions in some New York hospitals — show up at the hospital for other ailments and then test positive for the virus.
“We are seeing an increase in the number of hospitalizations,” said Dr. Rahul Sharma, emergency physician in chief for Newyork-presbyterian/weill Cornell hospital.
But the severity of the disease looks different from previous waves, he said. “We’re not sending as many patients to the ICU, we’re not intubating as many patients, and actually, most of our patients that are coming to the emergency department that do test positive are actually being discharged.”
Although it’s still early for firm predictions, the shift in hospital patterns fits with emerging data that omicron may be a variant with inherently milder effects than those that have come before, less prone to infecting the lungs, where it can cause serious disease.
But the lower proportion of severe cases is also happening because, compared with previous variants, omicron is infecting more people who have some immunity, whether through prior infection or vaccination. The vast majority of omicron patients in ICUS are unvaccinated or have severely compromised immune systems, doctors said.
Hospitals, facing staff shortages, are under enormous strain. In New York City, hospitalizations have exceeded the peak of last winter’s surge.
Gov. Larry Hogan of Maryland declared a state of emergency Tuesday, noting that the state had more hospitalized COVID-19 patients than at any previous point during the pandemic.
“We’re in truly crushed mode,” said Dr. Gabe Kelen, director of the Johns Hopkins University School of Medicine’s emergency department in Baltimore.
The number of ICU patients is a lagging indicator, likely to rise in the coming weeks, experts said. What’s more, some states are still struggling under the crush of hospitalizations from delta, a previous version of the virus that may be more virulent. Hospitals are frequently in the dark about which variant newly admitted patients are infected with.
Still, several reports suggest that omicron is a foe different from the variants that came before. And the challenges hospitals face — at least so far — are less about stockpiling equipment and more about staffing and contagion, doctors said.
“Early on in the pandemic, we were worried about running out of things, like ventilators,” said Dr. Ryan Maves, an infectious disease and critical care physician at the Wake Forest School of Medicine in Winston-salem, North Carolina. “Now, the real limitations are obviously physical bed space, but even more so, it’s staffing.”
When reports emerged in early December that hospitals in South Africa were handling relatively few severe omicron cases, experts stressed that the findings should be interpreted with caution. South Africa has a relatively young population, and a large proportion had been infected by previous waves, leaving the affected people with some preexisting immunity.
But now that the virus has spread across the world, there is more evidence that many people who have been infected with omicron in recent weeks seem to be faring better than those who were infected with other variants or during earlier surges.
In Britain, people with omicron were about half as likely to require hospital care and one-third as likely to be admitted to the hospital from emergency rooms than those infected with delta, according to a government report released last week. Early reports from Canada suggest a similar pattern.
A new report from the Houston Methodist health care system, which has been sequencing the vast majority of viral samples from its patients since February 2020, found broadly the same thing.
By Dec. 20, the new variant was causing more than 90% of new COVID-19 cases at Houston Methodist. In the new analysis, researchers compared 1,313 symptomatic patients who had been infected with omicron by that date to Houston Methodist patients who had been infected with the delta or alpha variants beginning earlier in the pandemic.
The numbers of omicron cases examined in Houston are small, and it takes time for the worst outcomes to manifest. But fewer than 15% of those early omicron patients were hospitalized, compared with 43% of the delta patients and 55% of the alpha patients, the study found.
Among those who were admitted, omicron patients were also less likely to require mechanical ventilation and had shorter hospital stays than did those infected with the other variants.
“On average — and I’m stressing on average — the omicron cases are less severe,” said Dr. James Musser, chair of pathology and genomic medicine at Houston Methodist, who led the research.
The omicron patients were also younger, and more likely to be vaccinated, than were those with previous variants, which may partially account for the milder illness.
Although the reports are encouraging, it is still too early, and there are not yet enough detailed data, to draw firm conclusions about omicron’s inherent severity, said Natalie Dean, a biostatistician at Emory University in Atlanta.
In New York City, cases have been steadily rising since December and are now overwhelmingly accounted for by omicron. COVID-19 hospitalizations have also increased sharply, and ICU admissions have been rising more slowly.
At New York University’s Langone Health, for example, around 65% of patients admitted with COVID-19 were “incidentally” found to have the virus, and their hospitalizations were not primarily because of the illness.
At Newyork-presbyterian, just under half of COVID-19 admissions were incidental.