Indiana Covid Update (1/21/2023)

The winter wave is ending a month earlier than expected and so far the new variant (XBB 1.5) isn't doing all that much.

In my last Covid update two weeks ago I said…

“it looks like […] we have passed the peak of the [winter] wave.”

… and that appears to have indeed been the case. Below is the latest dashboard of Covid metrics for Indiana, and all metrics are falling fast. The two metrics I always look to first are:

1. Wastewater concentration, which is our best measure of current spread, is at the lowest recorded level ever (for the 11 counties included here, data only go back to July 2022).

2. Hospitalization data, which is our best measure of current severity of cases, is falling and at a low level (in the lowest 25% of all days since the pandemic began).

For the remaining metrics:

• Test positivity rate is still high relative to past levels, but this is mostly a reflection of the continued decline of officially recorded testing. It would be a mistake to try and interpret the level, but the trend (falling positivity rate) suggests a slowing rate of infections.

• Daily new cases are low, but with testing rates continuing to decline, it would also be a mistake to compare levels with earlier periods. As with positivity rate, the trend (falling cases) suggests a slowing rate of infections.

• Daily deaths are at a moderate level but falling. This is expected as deaths tend to lag several weeks behind infections.

Should I worry about the new XBB 1.5 variant?

I want to repeat something I say every time the media and other influencers show alarm over a new variant:

It is normal and expected for new variants to emerge and become dominant. If a new variant develops that can out-compete the previous one, it would be unusual if it did NOT rapidly become the dominant strain. A new variant rapidly becoming dominant does not automatically mean we need to be more concerned about this variant than the previous.

In my opinion, statements like: “new variant X has risen from Y percent of all infections to Z percent of all infections at an alarming rate!” are meaningless if not misleading. The percentage of infections that are a particular variant isn’t as meaningful as what’s happening with the number of infections. Put another way, if infections are plummeting, we don’t really care what particular strain is dominant. This is what we’re seeing with XBB 1.5 right now.

Below is a screenshot of the CDC’s Variant Proportions dashboard, showing how XBB 1.5 has rapidly risen to making up about half of all infections nationally. Yet, wastewater data shows Covid infections have plummeted, and hospitalization data shows no increase in infection severity, over this same time.

While it is true that each new variant that becomes dominant has the potential to be devastating, we haven’t really encountered one that has yet (perhaps with the exception of Delta), and worrying about the rise of each new variant without clear evidence it could be more severe, is probably almost as bad for your health as a Covid infection.

How do we know the winter wave is really over?

The best evidence I can provide that the winter wave is over is the chart below.

Average daily hospital admissions for Covid in Indiana peaked on December 31st, 2022 at 135 admissions/day. Since then admissions have plummeted and today, less than three weeks later, we’re at 69 admissions/day (50% less). While we only have two earlier winter waves to compare with, during both we didn’t see such a huge decline in hospital admissions until the winter wave was over. From eyeballing the chart above, it looks a lot like this winter wave began about a month later than the previous two years and ended about a month sooner.

The 2022-2023 winter wave has been the mildest winter wave so far and by a large margin, with ~70% fewer hospital admissions and ~80-90% fewer deaths than each of previous two winter waves. But this doesn’t mean we should get complacent. There’s strong evidence that the reduction in severity has been mostly due to vaccinations.

• If you’re not vaccinated yet, there’s no better time than now.

• If you’re not up-to-date on your boosters, now is also the best time to take care of that (particularly if you haven’t received a bivalent booster yet).

• If you want to reduce your risk of catching Covid, or other respiratory viruses like influenza or RSV which also suck, wearing a good high quality mask (N95, KN95 or KF94) in public spaces provides excellent protection.

While we’ve made it through the 2022-2023 winter wave, this almost certainly won’t be the last. During both of the last two years, we had new waves begin in mid-March or early April and the most reasonable expectation is that that will happen again this year. As the severity of Covid infections measured in hospitalizations and deaths continues to decline, we can now focus more attention on less-severe but still potentially devastating long-term outcomes like Long Covid.

While it’s probably a controversial opinion, I’m excited that this weekend we’re finally predicted to get some snow up here in Northwest Indiana. It’s been nice having such mild winter weather, but I’d be very disappointed if we didn’t get a few snow days full of sledding before the winter was over.

Thanks for reading this far! If you have questions or comments, post them below!