Case Update, December 21st, 2021; Omicron overtakes Delta in the US!

This is a case update. I’ll also discuss the new Omicron numbers in the United States, and reevaluate if Omicron will represent our way out of the pandemic.

In terms of whole numbers, cases are still increasing in the US, mostly in the Northeast. In some amazing news, most of the cases in the Northeast are now from Omicron and not Delta (more detail on this below).

Graph is by me, from data collected from Johns Hopkins University COVID site. Graph is presented in a linear format.
Graph is by me, from data collected from Johns Hopkins University COVID site. Graph is presented in a linear format.
Endcoronavirus County Level Map, December 20th, 2021
Endcoronavirus State Level Map, December 21st, 2021

In California, cases are still at a persistent number, at around 5,000 new cases a day.

Graph is by me, from data collected from Johns Hopkins University COVID site. Graph is presented in a linear format.
Graph is by me, from data collected from Johns Hopkins University COVID site. Graph is presented in a linear format.

San Diego is continuing to experience a burst in cases right now.

Graph is by me, from data collected from San Diego County Public Health. See also regularly updated slides from SD County. Graph is presented in a linear format.
Graph is by me, from data collected from San Diego County Public Health. See also regularly updated slides from SD County. Graph is presented in a linear format.
Graph is by me, from data collected from Johns Hopkins University COVID site. Graph is presented in a linear format.

Omicron rapidly overtakes Delta!: In amazing news, cases from Omicron already outnumbers cases due to Delta in the US, and are 90% of new cases in some regions. Last week, the CDC was reporting that 3% of US cases were from Omicron. This week, they revised that number upward to 12%, but also reported that for 12/18, 73% of COVID cases in the US were caused by Omicron, 60% in the Southwest. I expect 95% of cases in the US to be Omicron by next week, and virtually 100% by New Years. This is potentially great news!

From the CDC page on Variant Proportions. Accessed December 20th, 2021.
From the CDC page on Variant Proportions. Accessed December 20th, 2021.

While still very early, a few other countries have started to produce data that can tell us what we might expect. In South Africa, the peak of new cases is already coming down. In previous waves there, peak deaths have trailed peak case by about 10 days. But for the Omicron wave, there is only a modest increase in deaths 10 days after peak new cases. This seems to confirm reports that Omicron produces very mild disease.

From Worldometer.
From Worldometer.

In the UK, Omicron cases are surging dramatically, with cases doubling every few days. In spite of this, there were 909 COVID deaths last week. In total, only 14 people have died from an Omicron infection this far. As Omicron spreads in the UK, we will likely see hospitalizations and deaths go down dramatically. I will caution that in the UK, deaths trail cases by about 12-20 days, and we are still early in the Omicron wave in the UK.

From Worldometer.
From Worldometer.

Back in the US, 90% of new cases in the Northeast are due to Omicron right now. In spite of this, total case numbers in New York are roughly double what they were a week ago. This means that of the 20,000 new cases daily in New York State, only 1600 are from Delta, the rest are from Omicron. So Delta cases in New York have gone down by 80%! Indeed, Omicron appears to be displacing Delta!

From Worldometer.
From Worldometer.

Keep in mind that we are only a few weeks into the Omicron wave, and things are still early. I will also caution that there are still a few people dying due to Omicron, so it’s not all over. Cases may be extremely high in the next few weeks. That being said, Omicron definitely has the potential to essentially end the pandemic, maybe in just a few weeks! If you’re one of my colleagues in the medical industry, start polishing up your post-COVID business models now!

I am NOT saying you should run out right now and get a nice case of Omicron. It’s still to early to say if that will be a good idea. For now, keep it together and stay cautious for just a few more weeks until we know more. I will also caution that I have a track record of being overly optimistic on my expectations of when the pandemic will end!

Given that the vaccines have some inherent risks of their own, and that Omicron appears to have very mild symptoms and completely ignores previous immunization, I do not recommend a booster to prevent Omicron infection at this time. Instead, those with risk factors should simply take precautions until the Omicron wave is over, or until more is known. As always, consult with your medical provider when making health care decisions. I am a molecular biologist, not a physician.

Omicron scorecard: Here’s my revised “scorecard” from last week. As a reminder, I am not an epidemiologist, I’m a molecular biologist. This is my informed but not expert opinion.

1) Omicron must not use the ADE pathway to produce more severe cases: Looking at the available data so far, while Omicron may preferentially infect those who have been previously infected, cases are still mild, and fatality rates very low. So for now, this criteria is met.

2) Low fatality in older populations: South Africa has a relatively young population, so reports of mild symptoms may not carry over to countries with older populations. The UK data from this week suggests that Omicron deaths will be low, even in older populations.

3) Displace Delta: Delta has a much higher case fatality rate in the US than Omicron appears to have. For Omicron to end the pandemic, it must displace Delta from the COVID population of strains. With the super high infectiousness of Omicron, it might just do that. Total Delta cases are currently down 80% since the start of the Omicron wave in New York State. This is very encouraging. This criteria is provisionally met.

4) Omicron must not circulate independently from Delta: Related to the above, if Omicron is very different from Delta, it may act as a completely different virus. There’s a chance that Omicron may displace Delta on the short term but still allow Delta to persist. Since Omicron is displacing Delta, it looks like this criteria may be met, but we won’t know for sure until we can see if Delta pops back up after the Omicron wave is over.

5) Omicron infection must immunize against future SARS-2: Since Omicron appears to infect those with immunity to Delta, it may be that it is different enough that it will not provide immunity to Delta or other SARS-2 strains. This criteria is not strictly necessary if Omicron completely displaces other SARS-2 strains (see 3 above), but it would be really nice to have some protection against future strains. We won’t know for sure about this one until a new version of COVID arises.

Don’t fear, but be smart!
Erik

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