Thread by @brownecfm

1/ A large part of my job is producing detailed reports for commercial clients regarding how the ongoing pandemic will affect the market in the future. Weeks, months, years.

2/ Since commercial clients are not interested in wishful thinking, the analysis I am expected to produce has to take into account a range of scenarios that government agencies are unlikely to consider.

3/ In early 2022, February I think, I posited the concept of what I termed, 'population cyclical immune dysregulation' in one of these reports. This was a *speculation* on my part, a worse-case scenario that was low-probability but high-risk.

4/ Population cyclical immune dysregulation - PCID - was what I speculated might happen if Covid-19 dysregulated the immune system of a percentage of the population, thus rendering this cohort more likely to develop secondary bacterial, viral, or fungal infections after Covid.

5/ In the context of very few countries having significant NPIs in place, so Covid-19 infection twice a year being the norm, my theory of PCID - stressing 'theory' - was that other pathogens would begin to become more prominent and present atypically.

6/ I went on to speculate that PCID could lead an inexorably downward spiral of population health: first Covid infection to secondary infection to second Covid infection to more secondary infections and so on. This would obviously place an unmanageable strain on health services.

7/ It also begs the question: do repeat Covid infections make people more likely to get another Covid infection? Could we see an acceleration of infections in 2023? An average of three a year, not two? Hopefully not.

8/ But what is increasingly, blindingly obvious to me: if we don't implement some level of NPIs until we develop second-generation high-efficacy vaccines and / or better therapeutics, we will not get off this downward spiral of plummeting overall population health.

9/ I never thought, in my lifetime, I would see an emergency department in Northern Ireland have to close its doors to new admissions because it was overwhelmed. This happened in Antrim a month ago.

10/ I never thought I would see critical shortages of children's penicillin. This is happening now.

These events are signals.

11/ If my concept of PCID is true - and I really hope it isn't - then this situation will get worse and worse and worse. There is no off-ramp as long as we allow Covid-19 to continue to transmit in the community completely freely.

12/ A combination of SARS-CoV-2 infection, secondary infections, sequelae of SARS-CoV-2 infection, Long Covid, and sequelae of SARS-CoV-2 induced secondary infections will continue to deplete the health of the population, in the face of reduced health care provision.

13/ We have to reduce transmission. /end.