[Lewis Thomson (OP)]

Roger is looking for help answering this question.

"It seems fairly certain you can catch Omicron more than once, but is there a period of immunity and if so how long is it? Is there a much smaller chance of catching it again (and how does this vary with time after catching the first time) and would it be less severe the subsequent time(s)?"

Leave your findings in the comments below...

[evan_au]

The experience from 4 other coronaviruses that have been circulating in the human population for a century or more is that your immunity wanes after a few years, so they tend to come back every 2 or 3 years.
- Your body retains some memory of the previous infections,  so they are generally mild, and we pass them off as "the common cold"
- However, it is likely that one of these 4, called OC43 first spread in humans in 1889-1890, and it caused a worlwide pandemic.
- It is likely that eventually SARS-COV2 will eventually become like OC43.
See https://en.wikipedia.org/wiki/Human_coronavirus_OC43

So it is likely that, if you have a normal immune system, you won't catch Omicron again within a year.
- However, Delta has not really gone away (it has just been swamped by the far greater numbers of Omicron cases)
- Infection with Delta does not provide much protection against Omicron (and probably vice-versa)
- It is possible that after the peak of Omicron passes, Delta may resume its gradually increase, at least in those countries that did not have many cases of Delta.
- It is totally unpredictable when new COVID variants might appear, except maybe to observe that we have had 4 waves in 2 years - and guess that maybe there might be another one 6 months after Omicron (perhaps in July, the Southern Hemisphere winter season)
- The World Health Organization (Dr WHO) is keen to see worldwide vaccination rates reach 70% during 2022, as they expect that this will reduce the chance of new variants appearing.

[set fair]

You can certainly catch Omicron and then catch what is being described as the sub-lieage of Omicron. This is because they are actually two quite different variants, but pretty much everyone is going along with "It's only a variant when the WHO says so." Perhaps the WHO is nostalgic for the early days of the pandemic, when, it spread disinformation freely. While on the subject of misclassifying, Delta should actually be called a new strain, it has two ways of infecting a cell - a new property which defines it as a new strain not a variant.

[evan_au]

Radiolab describes the saga of an immune-suppressed cancer patient who caught COVID.
- This unfortunate individual churned out 1 or 2 new COVID variations per week over several months, until he eventually succumbed.
Read transcript or listen: https://www.wnycstudios.org/podcasts/radiolab/articles/dispatch-14-covid-crystal-ball

[Bored chemist]

Perhaps the WHO is nostalgic for the early days of the pandemic, when, it spread disinformation freely.

That's probably legally actionable.
It's certainly not true.