COVID-19 cases and hospitalizations are increasing around the D.C. region following the Thanksgiving holiday – and amidst the arrival of the new omicron variant.

As of Sunday evening, all three jurisdictions – D.C.,Maryland, and Virginia, had confirmed cases of the omicron variant, which early data suggests may be more transmissible than the highly contagious delta variant. (It’s unclear if the omicron variant also leads to more severe illness, as existing cases have appeared to be mild.) All three jurisdictions are also reporting significant jumps in new COVID cases and a concurrent rise in hospitalizations over the past month, just as another holiday travel season approaches.

“What we’re seeing is what we expected to see,” says Neil H. Sehgal, a public health professor at the University of Maryland. “With colder weather, more indoor activities, an increase in family and friends gatherings, and of course with travel…we would see an uptick in cases. We’re not on the trajectory we were this time last year, in terms of magnitude, but we’re definitely following the same pattern.”

According to D.C.’s most recent data, the daily case rate per 100,000 is roughly 24, nearly double what it was one month ago. Hospitalizations due to COVID-19 have also doubled since last month; as of Dec. 9, 101 people were hospitalized in D.C. with COVID compared to 47 on Nov. 9. Still, roughly 6% of the city’s recent cases have resulted in hospitalization, according to the city’s data, and a majority of new cases are occurring in unvaccinated individuals.

“The hospitalizations we’re seeing today is a shadow of that Thanksgiving travel and gathering induced surge,” Sehgal says. “Anytime you see a surge in cases, the virus finds more people who are immunologically naive, who’ve never been vaccinated and have never had a previous infection. So the uptick in hospitalizations today, especially because our surge is mostly driven by delta at the moment, are principally those people who managed to not contract COVID previously, but also never decided to get vaccinated.”

In the last seven days, 62% of new infections in D.C. occurred in unvaccinated individuals over 12 years of age, according to D.C.’s data. Unvaccinated children accounted for 16% of cases, and fully vaccinated people made up 22%. As of Dec. 14, roughly 64% of the city’s total population is fully vaccinated.

In a press release announcing the identification of four omicron cases on Sunday evening, DC Health stressed the importance of vaccines and other health precautions in mitigating further spread. Mayor Muriel Bowser dropped the city-wide indoor mask mandate in late November – a move widely criticized by lawmakers. Instead, she and DC Health Director LaQuandra Nesbitt issued a stern recommendation – not mandate – that individuals mask indoors, regardless of vaccination status.

“The recent emergence of the Omicron variant further emphasizes the importance of vaccination, boosters, and prevention strategies (e.g. masking, washing your hands frequently, choosing activities wisely, and physically distancing from others) needed to protect against COVID-19,” the department said in the news release.

The upward trend of hospitalizations and cases looks similar across the region – although deaths from the virus across the D.C. area have not mirrored the spike in hospitalizations, and remain stable.

On Dec. 10, Maryland Gov. Larry Hogan announced a slew of new directives for hospitals as the state surpassed 1,000 hospitalizations due to COVID-19, a 100% increase from three weeks prior.. The health department is calling on hospitals to maximize ICU bed capacity, and take extra steps to beef up staffing, like granting temporary licenses for healthcare workers and eliminating administrative limits for out-of-state practitioners. Hospitals are also expected to implement practices to “balance patient admissions” to make enough space for COVID patients, and utilize alternative care sites.

“State health officials are taking these additional actions as we continue to use every tool at our disposal to help Maryland hospitals have the resources they need to respond to this and future hospital surges,” Hogan said in a press release last week.

In Montgomery County, the case rate per 100,000 residents has doubled in the past month, and hospitalizations have risen by 76% since this time in November. Sean O’Donnell, the emergency preparedness manager in the county’s health and human services department, said on Monday that a majority of the infections in the county – one of the most vaccinated jurisdictions in the country – are occuring in unvaccinated individuals.

“I know a lot of people are coming out and getting their boosters now, we’re very happy to see that as well,” O’Donnell said. “But we want to continue having those dialogues with members of our community who haven’t gotten fully vaccinated, because that is one of the primary ways this is spreading.”

In Prince George’s County, new infections in the past month haven’t increased at the same rate as its neighbor Montgomery County, or the state, but have still climbed. Hospitalizations have also risen in recent weeks, mirroring the trend across the region.

The average number of new infections in Virginia has increased by nearly 90% over the past month. As of Dec. 13, 1,230 people were hospitalized with COVID in the state, a 43% increase from Nov. 13. Per the state’s breakthrough data, new infections are predominantly occurring in unvaccinated individuals. Less than 0.1% of fully vaccinated Virginians have been hospitalized with breakthrough COVID infections.

While case loads and hospitalizations are not expected to match the levels of last year’s post-holiday surge, Sehgal says the potential of exponential omicron spread is cause for concern as the winter months wear on. In South Africa, where the omicron variant was first detected, cases surged dramatically from around a few hundred cases a day to more than 4,500 a day following the variant’s emergence. Vaccines are still believed to be effective in preventing serious illness and death from omicron, but the unvaccinated are still just as vulnerable, according to Sehgal. There is also concern that the omicron mutations may evade antibodies, meaning people who previously contracted COVID-19 could be reinfected, or vaccinated individuals could contract breakthrough cases.

“There’s no indication right now that for somebody without antibodies at all – somebody who’s never been vaccinated and never previously contracted COVID-19, the people who are ending up in hospitals today – that an omicron infection would be any less worse than delta,” Sehgal says.

In D.C., the first four cases of omicron occurred, in four unrelated individuals who were fully vaccinated. Three of those infected had recently traveled domestically, to Florida and New York, Virginia, and Maryland. One person was eligible for a booster but hadn’t received it yet, and the booster status of the other three cases is unknown.

While officials say they’re focused on getting first doses into arms, public health leaders have also urged all eligible individuals (anyone over age 16 that is six months out from their initial vaccine course) to get their booster shot – potentially adding an extra layer of protection from the omicron variant.

“We are doing quite well in the District, trying to encourage more vaccination. It’s just with this impending wave that we are likely to see a new and more transmissible variant…we need multiple layers of prevention,” Sehgal says. “DC Health says that masks and distance are needed to protect against COVID-19….but they haven’t reinstated policies requiring these necessary precautions.”

When DCist/WAMU reached out to DC Health on Tuesday for comment on whether the city was considering reinstating an indoor mask mandate amid the detection of omicron and a rise in hospitalizations, a spokesperson directed DCist/WAMU to Bowser’s Dec. 2 mask recommendation, and a link to her press conference that day.