Covid hospitalizations from delta variant creep up again across America as omicron lands in U.S.

Covid-19 hospitalizations are on the rise again across the U.S., even as health officials grapple with the news that the omicron variant has been detected in the country.

It’s too early for omicron to affect case numbers or hospitalizations in the U.S., where the delta variant still accounts for more than 99% of all new cases, according to the Centers for Disease Control and Prevention.

Although the country is still far from the delta wave’s peak in early September, when more than 100,000 patients were hospitalized with the virus, severe cases have begun creeping back up with colder weather in the North and people gathering to celebrate major U.S. holidays.

About 56,000 Americans are hospitalized with Covid-19, according to a seven-day average of Department of Health and Human Services data through Wednesday, up 8% over the previous week and 20% from the country’s most recent low point on Nov. 10.

The rise in hospitalizations follows the country’s latest surge in infections. Average daily cases peaked at more than 172,000 per day in mid-September before falling sharply and then plateauing at a high level of between 70,000 and 75,000 new cases a day for nearly three weeks through early November, data compiled by Johns Hopkins University shows. Cases then climbed once again, reaching an average of nearly 96,000 per day on Nov. 24, before the Thanksgiving holiday interrupted many states’ data reporting practices.

Most states did not report case or death numbers on Thanksgiving, according to a list maintained by Hopkins, and many delayed reporting through the holiday weekend. Combined with the fact that numerous states have scaled back their daily Covid data reports to just weekdays or even once per week, it could take days or weeks for local agencies to clear testing backlogs and report new cases that occurred in the days surrounding the holiday. 

This is why reported state and national Covid cases and fatalities typically drop sharply in the days following a holiday and then spike as backlogs are cleared. The latest U.S. average has dropped to about 86,000 daily cases as of Wednesday, for example, which will likely climb over the next week.

Hospitalizations, which measure the number of patients in hospital beds with Covid, have historically been more stable during holiday periods and less affected by reporting interruptions.

A combination of colder weather pushing people indoors, drier air, holiday travel and parties are some of the reasons behind this latest worsening of the outbreak, said Dr. Bruce Y. Lee, a professor of health policy and management at the City University of New York School of Public Health. Some Americans who got sick from Covid early on in the pandemic or were vaccinated in the spring and have not yet had a booster shot may also have waning immunity, he added.

At the same time, U.S. vaccination rates have increased, but at a slower pace. Nearly 60% of Americans are fully vaccinated, according to CDC data as of Tuesday. It has been nearly four months, though, since that figure reached the 50% mark in early August. It took just over two months for the nation to go from 40% to 50% and less than one month to go from 30% to 40%.

“Our vaccination numbers are not where they need to be, still, and I think despite our best efforts we are facing a future where it seems many people who are not vaccinated do not intend to get vaccinated,” said Dr. Lisa Maragakis, senior director of infection prevention for The Johns Hopkins Health System.

That will make it harder for the U.S. to get Covid to a place where it is “endemic,” Maragakis explained, which would mean that it is not totally eradicated but becomes more manageable and one of the respiratory viruses that the country deals with on a yearly basis.

“That is not going to be the case as long as we have large pockets of unvaccinated people,” she added.

These trends were already in place before news emerged of the omicron variant, which was reported by South Africa about a week ago. As the global scientific community investigates the strain’s transmissibility and whether it may cause severe disease or evade some protection from vaccines, nothing has changed yet about what the U.S. needs to do to mitigate Covid risk, according to Lee. 

“It’s a reminder that we need to retain all of those precautions because we thought a winter surge was coming anyway,” he said. Getting vaccinated and receiving booster shots, wearing face masks, social distancing where appropriate, and maintaining good ventilation are still key tools in fighting the spread of the virus.

As has been the case throughout the pandemic, the current outbreak varies regionally, with hotspots moving away from the U.S. South, where the delta wave hit earliest and hardest over the summer, to the Midwest. Hospitalizations are highest on a population-adjusted basis in Midwestern states, where they are up 31% over the past two weeks.

“Some regions of the U.S. are not feeling it,” said Maragakis, “but certainly when I talk to colleagues in Utah or Michigan or several other states, they are really in a crisis situation.”

Michigan’s more than 4,300 hospitalized Covid patients gives the state the highest rate of per capita Covid hospitalizations in the country, according to a CNBC analysis of HHS data. The volume of patients, staffing challenges, and duration of the pandemic have made this wave “more challenging than prior surges,” said Dr. Darryl Elmouchi, president of Spectrum Health West Michigan, a system of 14 hospitals across the western side of the state.

The 464 Covid patients in Spectrum Health hospitals as of Wednesday is the system’s highest mark yet, with hospitals so full that there is limited ability to transfer patients who need more care to other beds across the system, for Covid or more typical health issues such as heart attacks or cancer.

The vast majority of those hospitalized with Covid are unvaccinated, at 91% as of late last week, Elmouchi said. There are more instances of breakthrough infections, but those are largely not resulting in a need for critical care.

Spectrum Health recorded about 140 Covid fatalities in November, a high count but lower than last December’s record of 192 despite this year’s higher level of hospitalizations.

The federal government has sent two Department of Defense medical teams to Michigan in response to a request from Gov. Gretchen Whitmer for additional staffing, one of which will work with Spectrum Health.

It will be some time before any impact on virus transmission from Thanksgiving gatherings is visible in the national Covid numbers. In addition to the complications of data reporting around holidays, it will take between two and four weeks for infections to be detected and reported based on the time it takes for people to develop symptoms and get a positive test and for their cases to be published by state and local systems, Lee said.

U.S. Covid cases and deaths hit pandemic peaks after the 2020 holiday season, at averages of more than 250,000 infections and 3,400 fatalities per day, in January of 2021.