Omicron variant "prefers" the vaxxed in Denmark
Hospitalization rate is 13% of cases taken with a week lag
A great “Omikronvarianten” report just came out of Denmark. A very interesting report and a lot of data. It is dated today, December 10. I will analyze hospitalization data and show that hospitalizations as percentage of relevant cases can be estimated as 12.9%. This compares to the relevant overall historical rate of 15% in the US based on “positive tests”, and compared to 6% historical rate in the US based on “all estimated symptomatic cases” in denominator.
You can see that by Dec 10, Denmark has 1,280 total cases. Denmark’s case numbers are growing very fast. For now, they seem to involve a lot of younger people, which is understandable as young people like to mingle and party and travel.
Despite relatively younger population, we see a surprisingly high number of vaccinated people infected.
Only 18 out of 1,280 were hospitalized. This is great, right? Not quite.
Hospitalizations lag cases by about one week, and cases are rising rapidly. There are important caveats to this, that I list below, but read on. The overall tendency for hospitalization graphs is to trail case graphs by a week. So, to see how many people end up hospitalized, we need to look at the number of cases from a week ago, and compare to the number of hospitalizations now.
The total number of cases as of Dec 3 is 139. (1+1+1+4+7+3+10+10+26+76 = 139) (see Table 2)
This means that the number of hospitalized as of Dec 10, related to the number of cases as of Dec 3, is: Hospitalization rate = 18/139 = 12.9%.
Let me list some important caveats about this number:
As I said, some people are tested upon hospitalization, and thus there may be more “cases” in the denominator that we are not aware of. But this is true about any other variants of Covid, so we can still look at the ratio of hospitalized to cases a week ago, for apples to apples comparison
Stated slightly differently, the number of cases in general may be underestimated. This, also, is true about previous variants of Covid. I provide relevant hospitalization rates for the US, based on both “only positive tests” and “all estimated symptomatic cases” basis, for comparison to Omicron.
Both the number of the sick now (1,280), sick a week ago (139) as well as the number of hospitalized (18) are small numbers very early in the game, and thus confidence intervals are large.
It is possible that persons with Omicron are hospitalized out of abundance of caution and to keep them under observation, not because they are truly sick.
Hospitalization rates are likely to change once more older people are involved (as a previous graph shows, right now Omicron is present disproportionately in the young).
Testing rates are possibly uneven or inaccurate, even though Omicron easily shows up on a PCR test as “SGTF”, of “Spike-Gene Target Failure”.
The cases disproportionately involve young people of 20-29 age group. It is possible that when Omicron spreads more widely to older people, hospitalization rates will change for the worse.
You can compare our calculated hospitalization rate as percentage of known cases, to the previously known hospitalization rates. For example, in the US, for the entire pandemic, we had 50,422,410 reported PCR-positive Covid cases, and 7,500,000 hospitalizations and estimated 124,000,000 symptomatic cases. So, for the US, the ratio of hospitalizations to reported PCR cases is 15%, and the ratio for hospitalizations to estimated symptomatic illness is 6%.
In Denmark for Omicron, we have a calculated 12.9% rate. And note that Denmark cases are younger for an artificial reason of being younger due to this being an early pandemic model. So if the virus keeps spreading, it may affect older persons and likely the hospitalization rate will increase. Denmark is probably very good at testing now and Danes are very responsible, so the best comparison is with the US 6% hospitalization rate for all symptomatic cases.
My best guess and expectations for US hospitalizations from Omicron, as percentage of all cases, is 7-20%, if hospital beds are available. This is all guesswork, but based on more and more emerging data.
So, however we look at numbers, they tell us that this is NOT a “mild” virus.
Let me type up a numerical example, using simple numbers to make a simple point. The numbers are not meant to be my exact estimates of hospitalization.
Let's say that Omicron multiplies 10 times every week, and 10% of Omicron cases are hospitalized exactly after a week of infection. Let me cite newspaper headlines:
Week 1: Omicron case detected in our country
Week 2: 10 Omicron cases in our country
Week 3: 100 Omicron cases, no hospitalizations reported, Omicron is mild
Week 4: 1000 Omicron cases, 10 hospitalizations, Omicron is a nothing burger
Week 5: 10,000 New cases,100 hospitalized, Omicron will end Covid pandemic
Week 6: 100,000 cases, 1000 hospitalized, EXPERTS STARTING TO WORRY
Week 7: You get the idea
Here’s the bad news:
Omicron seems to be targeting the vaccinated
The most interesting finding is this. Omicron’s cases involve only 177 unvaccinated persons, and 1,103 vaccinated persons. So, 87% of Omicron cases are vaccinated fully or partially.
Of note, 13% of Omicron cases are unvaccinated, whereas 17% of Danes in general are are unvaccinated. Even fewer of younger Danes received vaccines. So, the vaccinated are represented disproportionately among Omicron cases, and the unvaccinated are underrepresented. Put in another way, being unvaccinated is an advantage for Danes exposed to Omicron.
This aligns with other news, such as 11 out of 12 Omicron cases in Oakland being vaccinated and boosted:
Kaiser Permanente said Wednesday that 11 of its vaccinated and boosted Oakland Medical Center workers were among a cluster of East Bay COVID-19 cases linked to the omicron variant — and that at least 16 patients and other staff members were exposed to them before the discovery.
Kaiser said Wednesday that the 11 infected members of its Oakland Medical Center staff were fully vaccinated against COVID-19 and had received booster shots.
Omicron is already 30% of cases in London.
Nothing makes this substack better than presence of smart, informed critics and commenters. Your thoughts and disagreement are most welcome. If you disagree, notice a mistake, have other recent data, or want to bring up something, please submit your comment!
Also note that Table 4 percentages are incorrect and they mixed up lines 2-4. Not my fault. It is not my table and it comes from Denmark. An astute reader noticed it.
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