The Oslo Omicron Outbreak had a 'breakthrough infection rate' of 73% among 'fully vaccinated'

Participants were 30-50 years, i.e., the middle-aged have a 'breakthrough infection rate' like seniors

The other day, the Norwegian Institute of Public Health (IPH) came out with a more thorough, if still preliminary, comment on the infamous Oslo Omicron Outbreak. If you’re kind of new to this facet, check out my earlier coverage of this event (here and here).

So far, we knew that a late-November Christmas Party in one of Oslo’s upscale restaurants led to a significant Covid outbreak, including the most recent ‘variant of concern’, Omicron.

According (Norwegian version, here’s the English version; I am using the former, due to the slight differences in-between) to the IPH, here’s the two main points (my emphases):

Of the 111 participants at the Christmas party that were interviewed, 80 individuals—that would be 73% of attendants—tested positive for Sars-CoV2 afterwards. Of these, 17 individuals (15%) have been confirmed with the Omicron variant (data as of 8 Dec. 2021).

There’s a disclaimer that reads that more Omicron infections may be identified going forward, but here’s the second main aspect:

‘All but one of those who were diagnosed [79 out of the 80 mentioned above] with SARS-CoV-2 reported symptoms…with more than 70% of them [that would be 55 or more of these 79 individuals] reporting cough, lethargy, headache, sore throat, and over half mentioned a fever, but no hospital admissions have been reported.’

What does the Oslo Omicron Outbreak mean?

Keep in mind that I’m not a medical doctor or even working in medical or life sciences. Like you, I’m able to read, though, and here’s my line of thinking:

This ‘event’ may be as pivotal as the now-infamous Delta Outbreak in Barnstable County Mass., where the CDC, in late July 2021, admitted to the following (my emphasis):

‘In July 2021, following multiple large public events in a Barnstable County, Massachusetts, town, 469 Covid-19 cases were identified among Massachusetts residents who had traveled to the town during July 3-17; 346 (74%) occurred in fully vaccinated persons.’

Note that the numbers by the Norwegian IPH are, somewhat oddly, strikingly similar: 80 (73%) ‘breakthrough infections’ occurred among the ‘fully vaccinated’ participants.

The main take-away, I propose, may be this:

All the participants in the Oslo Omicron Outbreak were between 30-50, according to the IPH.

We already know that the ‘breakthrough infection rate’ among seniors (60 or older) is slightly higher than 70% (this data point comes from the German CDC equivalent, the Robert Koch Institute, per their weekly update from 9 Dec. 2021, p. 23, table 3).

The age bracket of 30-50yo Norwegians were vaccinated in the period from late May through June 2021, i.e., six to seven months ago.

Irrespective of certainly relevant questions about ‘fading vaccine efficacy’, here’s the main take-away as I see it:

Six months after becoming ‘fully vaccinated’, the ‘breakthrough infection rate’ among 30-50yo appears to be in the same ballpark than that of senior citizens.

Let that sink in.