REGIONAL- There’s reason to question new Centers for Disease Control estimates of the prevalence of Omicron coronavirus variant cases widely reported nationally on Monday. Yet, with all but four states now reporting cases of the highly contagious virus, it’s likely that Omicron will soon short-circuit the recent downward trend of cases in Minnesota and increase pressure on an already overburdened healthcare system.
Two key indicators provide evidence that the peak of the Delta-driven fourth wave of the pandemic in Minnesota is likely behind us. On Monday, the state reported a seven-day daily average new case count of 3,177. That’s a 33-percent drop in that same measure from the data reported on Dec. 7. And the seven-day test positivity rate dropped under double-digits for the first time in weeks, to 8.2 percent. Both data points suggest declining cases— at least for now. But all recent forecasting bets are off now that the rapidly spreading Omicron variant is making major inroads in the U.S., suggesting it could become the dominant variant in the U.S., as it has in Great Britain, South Africa, and elsewhere.
The Centers for Disease Control updated COVID infection modeling estimates on its website Monday, based on data gathered through its national genomic surveillance system, that in only one week estimates of Omicron infections skyrocketed from 12.6 percent of new cases to 73.2 percent. Regional variations range from a high of 96.3 percent in the Pacific Northwest to 30.6 percent in the region comprised of Nebraska, Kansas, Iowa and Missouri.
But many of the splashy headlines and breaking news stories on national and regional media outlets reporting the CDC data on Monday night had disappeared by Tuesday morning as multiple sources began questioning an astronomical increase that exceeded any prior data of how quickly Omicron has increased in other parts of the world.
A blog post by Ari Allyn-Feuer, an Artificial Intelligence engineer at a major pharmaceutical company, asserted that the sustained doubling rate of Omicron cases necessary to generate such estimates far exceed documented experiences in the United Kingdom and Denmark that indicate doubling times between two and four days, not the 36 hours needed to account for the CDC’s 73.2 percent estimate.
“This is out of touch with what we know about Omicron,” Allyn-Feuer wrote. “It’s not credible.”
He also noted that the CDC didn’t make any announcement about the number and claimed that the estimate had to be a result of a bug that would be walked back soon by CDC officials. However, he also didn’t downplay the seriousness of Omicron growth.
“Still prepare for Omicron to become dominant in your area within weeks (or already),” he said. “That’s real, and it’s still on.”
The emerging data from other countries does support the claim that Omicron’s rapid spread has outstripped every other variant of concern to date. In less than a month since the discovery of the Omicron variant was first announced by health officials in South Africa, the new COVID strain had been identified in all but four U.S. states and more than 85 countries worldwide as of Monday.
On Dec. 16, the Minnesota Department of Health confirmed that seven Omicron COVID cases had been identified in the state since the first was reported, and that only two of those cases were linked to each other or involved out-of-state travel, indicating that community spread is happening in the state. Six of the cases were in the Twin Cities area and one was in Greater Minnesota. On Monday, the GISAID global Omicron database indicated Minnesota’s count had risen to 13.
“When we consider the introduction of Omicron into our community — we have cases in Minnesota that clearly were the result of community spread — it’s all that much more important ... to be attentive to mitigation measures like masking indoors,” said state infectious disease director Kris Ehresmann.
One of the first attempts to model the potential impact of Omicron in the U.S. was released Dec. 16 by researchers at the University of Texas-Austin. In what they called their most “optimistic” scenario, with 80 percent of vaccinated people receiving booster shots by March 1 and virus transmission similar to Delta, the U.S. would see 14.3 million new Omicron cases by May 1, including 682,000 hospitalizations and 182,000 deaths.
However, with less than 30 percent of those eligible for boosters nationwide taking advantage to date, and recent research indicating that the Omicron variant is at least four times as contagious as Delta, the “optimistic” scenario from UT-A is unlikely. In their most “pessimistic” scenario, UT-A researchers predict daily COVID caseloads more than two times higher than at the highest point of the pandemic in January 2021, leading by May 1 to 26.3 million new cases, 1.6 million hospitalizations, and 342,000 deaths.
While the reality will likely fall between those extremes, Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota said in a Friday podcast that he expects a “viral blizzard” in upcoming weeks and months.
“It is so difficult at this point … to actually know what to tell you because (information) is coming out so rapidly; the information is confusing and frankly challenging,” Osterholm said. “I think we are going to see a viral blizzard literally ascend upon the world with Omicron, and the questions will be what will that mean clinically, from a public health standpoint, and from a medical delivery standpoint?”
With over 50 genetic variations from other COVID strains, emerging research indicates that Omicron is more infectious than the highly infectious Delta variant and has the ability to circumvent the antibodies produced by standard-dose COVID vaccines and prior COVID infections. The mRNA Pfizer and Moderna two-dose vaccines combined with a booster shot appear to have the best chance at warding off serious illness, hospitalizations and deaths from Omicron.
Osterholm stressed the importance of getting booster shots.
“Two doses of vaccine is a 50-foot rope,” he said. “People are all drowning a hundred feet out. A booster dose gives you the full hundred feet of the rope. That’s what you need to save people.”
However, for the four percent of vaccinated Minnesotans who received the Johnson & Johnson vaccine, early indicators suggest that booster shots will do little to improve their immunity against Omicron infections, as is the case with other non-mRNA vaccines developed and extensively used in other parts of the world.
Natural immunity from prior COVID infection also provides little protection against Omicron, which carries a “three-to-eightfold increased risk of reinfection,” according to Osterholm.
“Those who continue to assert that previous infection is by itself sufficient for ongoing protection, that’s not the case,” he said. “Even those who have been previously infected do need to be boosted with vaccines.”
Osterholm also said last week that early reports of Omicron causing less serious illness seemed to be holding up. However, on Monday, researchers at Imperial College in London reported data on a group of 11,300 confirmed or likely Omicron infections that cast serious doubt on that assessment. They said that they see ““no evidence of Omicron having lower severity than Delta, judged by either the proportion of people testing positive who report symptoms, or by the proportion of cases seeking hospital care after infection.”
It’s also unclear at this point what effect Omicron may have on Delta variant case levels. Some health officials have said that Delta could remain a significant source of COVID infections even with the emergence of Omicron as the dominant variant, while others suggest Omicron might push Delta out of the way as a major factor.
“It’s Omicron against Delta and we don’t know where that’s going to play out yet,” Osterholm said. “The one thing you can do more than anything else, to protect yourself, your family, your loved ones, all the people you work with, your neighbors, the people you go to church with, the people you go to social events with, is to be fully vaccinated with your booster, too. That will give you the best opportunity to prevent any kind of serious illness from occurring and maybe even have some impact on transmission.”
Local data
Along with the rest of the state, case numbers in St. Louis County have been trending downward since early December, after tallying 5,019 new cases in November. The seven-day case average dropped to 94.7 on Dec. 14, almost half of what it was on Dec. 2.
Ely’s new cases were down slightly to 24 in the Dec. 16 weekly case report, while new cases in Cook were up from six the prior week to nine. Embarrass and Tower each added six new cases, Orr added two, and Soudan had no new cases reported last week.