As in most of the Western world, so too in Alaska now.
State Department of Health and Social Services officials Wednesday reported that the Omicron (Greek symbol Oo) variant of the SARS-CoV-2 virus has now displaced the Delta variant and become almost wholly dominant in the 49th state.
As of Jan. 6, state sequencing data showed Omicron responsible for 91 percent of the cases of Alaskans sick with Covid-19, the disease caused by the new pandemic virus, Jayme Parker, the section chief for Alaska Public Health Laboratories told a noon videoconference of Alaska public health officials.
“I would imagine today (Wednesday) that this percentage is reaching rates similar to the Lower 48 (at) 99 percent omicron,” she messaged later in the day.
The variant’s rise has been swift since it was first reported in South Africa on the opposite side of the globe from Alaska on Nov. 24. Within about week, an American returning from that country was reported to have brought it back to the U.S.
By then, it was already spreading in Europe, and the World Health Organization (WHO) was by Dec. 21 warning of “another storm coming – Omicron is becoming, or already has become, dominant in several countries, including in Denmark, Portugal and the United Kingdom, where its numbers are doubling every one and a half to three days, generating previously unseen transmission rates.
“Within weeks, Omicron will dominate in more countries of the region, pushing already stretched health systems further to the brink. Omicron is likely to become the dominant variant circulating in our region.”
With 7 million new cases in Europe by Jan. 11, Hans Kluge, the WHO director for the continent, told a news conference that half of the people in Europe could expect to be infected by the virus by the end of February or early March.
The virus was then in the process of storming North America as well. The spread of Omicron in Alaska has mimicked its rise in Europe and the Lower 48, only with a lag time of a week or two.
By Christmas, Parker said, omicron was showing up in about 53 percent of the samples coming into Alaska laboratories. The number was up to 77 percent just before the New Year and continued to increase afterward.
The good news – if there can be any good news associated with getting sick – is that Omicron appears far less dangerous than the Delta variant it has pushed aside.
After examining the files of nearly 70,000 patients in The Golden State, a University of California Berkley study funded by the U.S. Centers for Disease Control (CDC) concluded that about a third as many patients were being hospitalized by Omicron as by Delta though hospitalization rates for both variants were low.
For Delta, 1.3 percent of 16,982 patients were admitted to a hospital, the study reported. For Omicron, the number dropped to 0.5 percent of 52,297.
Once in hospital, the chance of an Omicron patient ending up in an intensive care unit (ICU) was about a quarter of that for a Delta patient, and the chance of an Omicron patient dying in the ICU was less than a tenth of that for a Delta patient.
As an illustration of the differences in severity, the authors of the study noted that “zero cases with Omicron variant infection received mechanical ventilation as compared to 11
cases with Delta variant infections….”
A study of more than a half-million patients from 63 health care organizations using records compiled by the “TriNetX Analytics network” reported similar results. Overall, that study found the risk of hospitalization with Omicron less than half of that with Delta.
The study also reported finding “that the risk for hospitalization in unvaccinated children under five years old that occurred after the emergence of the Omicron variant was one-third of that during the Delta variant period (0.96 percent versus 2.65 percent) whereas the risk for emergency department (ED) visit was less than one-fifth (3.89 percent versus 21.01 percent), both differences were significant.
“The same trends were observed for children 5-11 and 12-17 years old. These results suggest that while pediatric SARS-CoV-2 infections and hospitalizations are reportedly rising, the outcomes are milder after the emergence of the Omicron variant as compared to the predominant Delta variant period that preceded it.”
The study authors from Case Western Reserve University School of Medicine in Cleveland also raised questions as to how much of this was due to vaccination campaigns and how much to the nature of the new variant.
“Though the decrease in disease severity in the emergent Omicron cohort could reflect increases in vaccination and boosters in the population between November and December, the proportion would have had to be quite substantial to account for the large reductions that we observed,” they wrote.
“In addition, we did not observe similar decreases in disease severity for infections occurring right before the emergence of the Omicron variant as might occur with a gradual ramp-up of vaccination. Moreover, since we selected persons who had not had prior SARS-CoV2, it is unlikely that the milder results occurred because of the persistence of viral mRNA from prior infection and not from new, acute infection.
“Taken together, it is likely that the emergence and increased prevalence of Omicron entrains milder diseases and is a major contributor to the observed decreases in disease severity.”
Avoid it anyway advice
Still, even infection with Omicron – as with the flu and other respiratory diseases – remains a serious threat to the old and those with chronic illnesses. The CDC warns of particular danger to people suffering from cancer; kidney, liver or lung diseases; obesity; auto-immune diseases; dementia; diabetes; heart disease and more.
The CDC website contains a complete list of co-morbidities likely to increase the risks of SARS-CoV-2 Omicron. Those with such illnesses are being advised to consult with their doctors, get vaccinated and isolate as much as possible until the Omicron wave subsides.
Vaccination appears only about half as effective against Omicron as against Delta, but still significantly lowers the chance of dying. Previous infection with SARS-CoV-2 does not appear even less effective against Omicron.
A study by scientists at the Imperial College London concluded that those previously infected with one of the earlier SARS-CoV-2 variants were more than five times as likely to become infected with Omicron as with Delta.
Spread by mice?
Omicrons many unique mutations have been cited for the the variants much greater attack rate as well as its apparently milder symptoms, and Chinese scientists think mice – or at least a mouse – might be to blame.
A group of them from the Chinese Academy of Sciences argue there is evidence for a “mouse origin of the SARS-CoV-2 Omicron variant.”
They say a variety of the mutations in the variant look little like those earlier seen in other variants known to have evolved in human hosts.
“The proximal origins of Omicron have quickly become a controversial topic of heated debate in the scientific and public health communities,” they add in a paper published in the December issue of the Journal of Genetics and Genomics. “Many mutations detected in Omicron were rarely reported among previously sequenced SARS-CoV-2 variants, leading to three prevalent hypotheses regarding its evolutionary history.
- “The first hypothesis is that Omicron could have ‘cryptically spread’ and circulated in a population with insufficient viral surveillance and sequencing.
- Second, Omicron could have evolved in a chronically infected COVID-19 patient, such as an immunocompromised individual who provided a suitable host environment conducive to long-term intra-host virus adaptation.
- The third possibility is that Omicron could have accumulated mutations in a nonhuman host and then jumped into humans.”
They concede the second hypothesis is the most popular, but argue the available evidence is more in line with the third.
“Collectively,” they write, “our results suggest that the progenitor of Omicron jumped from humans to mice, rapidly accumulated mutations conducive to infecting that host, then jumped back into humans, indicating an inter-species evolutionary trajectory for the Omicron outbreak.”
Mice are just one of a long list of animals – including North American whitetail deer – that SARS-CoV-2 is now known to have infected. And these animal reservoirs for the disease make it likely that SARS-CoV-2 will – like the flu – be troubling humankind for a long, long time to come.
At a time when Iceland and New Zealand, two islands nations, had managed to hold SARS-CoV-2 at bay, some suggested the possibility the disease could be eradicated.
“In this very preliminary analysis, COVID-19 eradication seems slightly more feasible than for polio, but much less so than for smallpox,” a team of Kiwi researchers reported in The BMJ, formerly the British Medical Journal, in August 2021.
New Zealand in August announced it was closed its borders to nonresidents until 2022 to try to control SARS-CoV-2. It earlier this week expanded the lockout to include residents trying to return home and people holding New Zealand work visas.
Despite the restrictions, Omicron is now on the island. The New Zealand Herald reported a double-vaccinated citizen who’d been quarantined after returning to the island from a trip Outside was found to be infected.
“This case was in a managed isolation and quarantine (MIQ) facility in Christchurch and tested negative on day nine, before being released on January 16, after returning five negative test results throughout their stay,” the newspaper said.
“The case became symptomatic (Tuesday) and got tested, returning a positive Covid-19 test result (that) evening.”
Only five cases are known on the island at this time, the Herald reported today, but health researchers are suggesting the number could reach 10,000 in a matter of weeks despite the country’s high rate of vaccination.
“….Hospitalisation rates due to COVID have dropped to 0.2 to 0.3 percent – down from around 2 percent when the Delta strain was dominant in Iceland,” according to the Iceland Review. “Nevertheless, Iceland’s National University Hospital is experiencing strain due to the sheer number of cases.”
And in the United Kingdom debate is raging over a government decision to essentially declare the pandemic over. Prime Minister Boris Johnson early this week announced that infections had peaked and that requirements for face masks and vaccination passes will disappear next Thursday along with government suggestions people work from home.
“Infections levels, while falling, are still well above what they were at the height of the peak last winter….(and) some scientists and public health experts have expressed concern the easing may be too much and risks a rebound in infections .”