Thread by @ASlavitt

COVID Update: Tens of millions could get COVID in the US this winter omicron wave.

What are the chances of getting infected during this wave? How much different from “normal” pandemic times?

1/

Let me try some basic math. This isn’t big math with log scales but the kind where the numbers are round enough because there are enough assumptions to make precision feel false. 2/

There are 250,000 recorded daily infections now. Actual estimates are that it’s actually about 4x higher counting for rising test positivity, test shortages & at home tests. IHME projects well over 1 million/day. 2/

covid19.healthdata.org/united-states-…

How many infectious people are there? Nationwide, if you assume 1 million new cases/day & if people were infectious for 5 days, that’s 5 million. (Yes I have those kind of math skills)

Some of those 5 mm will isolate— hopefully the 1.25 million who test positive. 3/

So say 3.5 to 4 million people (or just above 1% of the population) would likely be infectious & in public.

So that’s a national average and we are likely weeks away from peaking.

What about during the wave’s peak in a hot spot? 4/

In DC, the biggest hotspot in the US has 186 cases/100,000.

Instead of 1% of the population, using the same math, DC would be closer to 3%. And DC hasn’t peaked yet.
5/

We can’t be sure how high it will climb but if you assumed 5% of people at peak could be walking around infectious, that doesn’t seem outrageous.

1 in 20 people you see might be infectious. This compares to 1 per 1,000 at a time of low prevalence. 6/

So compared to low prevalence times, the takeaway is that you could be 50x as likely to interact with someone with COVID.

If omicron is more contagious, it could also take less exposure to a person or a room to get infected. 7/

Reasonable people could come up with more sophisticated analysis.

But even so, risks of walking into a store or restaurant or school and getting g COVID are multiples higher.

And household spread is higher. 8/

So far hospitalization rates are much lower.

Hospitalizations used to follow cases very predictably. So far, in major hot spots this has changed. This is c/o @HealthIndAdv. 8/

While hospitalizations are up, with omicron so far the likelihood of a case leading to a hospitalization is lower. 9/

One explanation— vaccines strongly protect against hospitalizations but allow breakthrough omicron infections. And the vast majority of hospitalizations are unvaccinated people.

Viral replication differences with omicron in the lungs could also be part of the reason.10/

The RATE of hospitalizations matters to us individually. But the NUMBER of hospitalizations matters to hospitals.

And that increase is enough to cause many hospitals to fill over the next month or two. 11/

There are many more reasons to avoid getting infected besides risk of hospitalization. Missing work, not seeing family, infecting others & risking long-term symptoms are all reasons we don’t talk enough about. 12/

Many of us live with people at real risk if they get sick. This level of spread makes anyone with a compromised immune system more at risk & more isolated.

Service workers & commuters are also at greater risk & not by choice. 13/

What to do about all of this if you want to avoid infection?

-N95 or equivalent masks in public
-test 2 days post exposure
-boost if you haven’t
-gather more outdoors & in smaller crowds

None of these are individually foolproof. All are smart in combination. 14/

COVID is causing a lot of disruptions several years running.

The near term future may be marked by these waves & the rough numbers tell me that risks go up meaningfully during these times. 15/

Even as we have more tools to manage these disruptions & these waves, the burden continues to fall disproportionately on those most vulnerable & with the fewest choices.

The steps we take can improve everyone’s odds. /end