COVID Transmissions for 1-31-2022
US hospitalizations falling; new evidence for boosters
Greetings from an undisclosed location in my apartment. Welcome to COVID Transmissions.
It has been 776 days since the first documented human case of COVID-19. In 776 in the Byzantine Empire, Emperor Leo IV appointed his 5 year-old son as co-ruler with him. This led to an unsuccessful—but, IMO, rather justified—revolt.
Today in COVID I want to discuss trends in the Omicron variant wave in the US, as well as make the case for booster vaccination using recent evidence from the CDC.
I also have an announcement to make:
Today is a special day for this newsletter! As you will notice, I have substantially reorganized the sections. There are a couple of reasons for this, but I will be pretty blunt in summarizing the chief one:
This newsletter is the #5 result for “covid” on substack1
There are newsletters ahead of it that contain substantial misinformation
Part of the reason it is not the #1 result is that I have made a lot of content free,2 and Substack cares about how many paid subscribers you have, not how many total subscribers
I am pretty annoyed to be ranked behind misinformation newsletters, and I want to fix that. Which means I need to encourage and reward paid subscription. However, I also believe strongly that essential COVID-19 information should be free.
In light of all this, I have decided to add a paywalled section to the newsletter, in one issue each week, but all the COVID-19 information will stay free. The only item behind this paywall will be the new “Other viruses” section, where I will discuss developments in virology that are not related to COVID-19.
This means reorganizing the other sections a little bit, because wherever I insert the paywall, everything after that point will be paid content. You’ll see today how that works. This also means today’s issue will only accept comments from paid subscribers—a setting I cannot change. Fully free issues will allow comments from everyone.
Look, I really hate paywalls, particularly for important information. However, Substack owns this platform and if I want to outperform the misinformation present on it, then to at least a certain degree I have to play ball by their rules.3
However, I want to make this easier on you, loyal readers. To that end I have created a limited-time offer4 that cuts 50% off the subscription price for an annual subscription (so that it is $25). For existing annual subscribers who have already paid, please email me during the offer period (though 2/28) and I’ll give you some comp time so that you get the equivalent of this deal.5
The offer can be found here:
Bolded terms are linked to the running newsletter glossary.
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Now, let’s talk COVID.
COVID-19 hospitalizations falling in the US Northeast and Midwest
People with COVID-19 are now, finally and thankfully, leaving US hospitals faster than new ones are entering them, with nationwide caseload in hospitals dropping from a record 160,000 to 150,000, per CIDRAP: https://www.cidrap.umn.edu/news-perspective/2022/01/covid-19-hospital-cases-drop-northeast-midwest
That article also has some interesting information on 4th doses being recommended in certain special populations, and on the possibility of an Omicron-specific booster from Moderna, by the way. Worth reading!
The change in hospitalizations is driven largely by drops in hospitalized cases in the Northeastern and Midwestern US. Hospitalizations are still rising in the South. It is not looking good everywhere.
Even though many places have peaked, please remember that when climbing to a tall peak, it can be more dangerous on the way down than on the way up. Stay safe out there.
Booster doses vs hospitalization
The US is behind the curve on giving booster vaccine doses, just as it is behind the curve on vaccinating people in general. So today, I want to explore where the current evidence is on the benefits of a booster dose in COVID-19—particularly because the Omicron variant has changed the game on us.
When the proposal was made that everyone in the US who received two doses of an mRNA vaccine should receive a third dose, I was, like many, skeptical that booster doses were the best strategy. That is because of the nature of the pandemic at that time, and because of low vaccine uptake in the US at that time.
With the emergence of the Delta variant, evidence began to come in that this variant could on some level evade immunity and allow vaccinated people to become infected with SARS-CoV-2, while before it was very likely for such people to avoid infection altogether. However, evidence also indicates that infections of vaccinated people with the Delta variant do not yield the same amount of virus shedding as do infections of unvaccinated people, despite initial reports.
With Delta, there was some argument that a booster dose was an epidemiological intervention that could limit the spread of this new virus variant. In that context, it began to make more sense to get a booster dose as we learned more. When the FDA and CDC both recommended it for adults, I went and got mine (and covered that decision in this newsletter).
One thing that was missing from this narrative was strong evidence about the ability of booster doses to impact hospitalizations due to COVID-19; it seemed that effectiveness of the available vaccines remained strong against hospitalization, with only minor reductions in most people, and apparently more severe reductions in people with compromised immune systems—something that is not surprising, but that we also want to remedy if possible.
We now have a better picture of this, thanks to a study from the CDC looking at mRNA vaccines: https://www.cdc.gov/mmwr/volumes/71/wr/mm7104a2.htm?s_cid=mm7104a2_w
This study looked separately at immunocompromised and immunocompetent people, during a period where Delta variant virus was thought to be dominant in the US. I say “thought to be” because the study goes up to December 15th, and surveillance of Omicron was rather poor in the US prior to mid-December. The study explored vaccine effectiveness against hospitalization, and found the following:
Immunocompromised patients
Vaccine efficacy (VE) against COVID-19 hospitalization with 2 doses: 69% (95% CI: 57—78)
VE against COVID-19 hospitalization with 3 doses: 88% (95% CI: 81—93)
Immunocompetent patients
VE against COVID-19 hospitalization with 2 doses: 82% (77—86)
VE against COVID-19 hospitalization with 3 doses: 97% (95—99)
These results make a very strong case for a protective effect of booster doses specifically against hospitalization. As you may notice, these numbers are different in such a way that the 95% confidence intervals do not overlap, suggesting they really are different. In fact, the p value, a measure of the likelihood that these results arose from random dataset variation and not a true difference, was less than 0.001 for all comparisons. That means that there is less than a 1 in 1000 chance these differences do not represent the overall reality for this dataset.
For people who are immunocompromised, the benefit of the booster dose was approximately 19 percentage points. For the immunocompetent, it was approximately 15 percentage points. What’s interesting to me here is that the benefit is so close—I might have expected the added benefit in people who are immunocompromised to be substantially larger, or substantially smaller. It could have gone either way.
When it comes to going to the hospital, 15 to 20 percentage points make a big difference to me.
Now, we do need to understand that the cases represented here are mostly Delta variant cases and the Omicron variant has changed things somewhat, but I would venture that there is still a definitive benefit of getting a booster dose. I don’t know if that benefit would be bigger, smaller, or the same, however. I would just bet that it is still there, and meaningfully.
What I don’t know for sure is how long the benefit of that third dose will last vs Omicron. Data from the UK have suggested that the period of added protection vs Omicron from a booster dose lasts only about 10 weeks (the protection gain may last longer than this; it’s just an estimate). That is not ideal, but it is better than 0 weeks.
Consider the duration of the Omicron wave in New York County when asking yourself if 10 weeks of added protection are worth it:
It seems to me that New York County, where I live, will be back to pre-Omicron levels of COVID-19 cases by mid-February, and we began to observe cases increases at the beginning of December. I will point out that this timeline is almost exactly 10 weeks.
A person who got their booster dose as cases began to increase would have had added protection against hospitalization for at least the duration of the most dangerous period of this peak, if not longer. Sounds good to me.
Now, I’ve mentioned before that there are companies working on Omicron-specific boosters. I think that’s great, and you may be wondering if you should wait for those. If you’re not boosted yet, I want to emphasize that there is no guarantee that these products will make it to market on the timeline that has been projected. I also want to emphasize that that timeline calls for these products to be ready for the public in several months—which, conveniently, is about as long as we think a booster dose may provide added protection in an Omicron-dominated world.
If I were an unboosted person, I’d get my booster, and be glad to have extra protection at least in the near term, until an Omicron-specific vaccine can be released.
I’ll take this opportunity to quote the CIDRAP article I linked in the last story:
The CDC currently recommends a fourth shot of COVID-19 vaccine for roughly 7 million Americans, including those with suppressed immune systems due to organ transplants, cancer treatments, or autoimmune diseases.
If you’re in that category, talk to your physician.
Part of science is identifying and correcting errors. If you find a mistake, please tell me about it.
Though I can’t correct the emailed version after it has been sent, I do update the online post of the newsletter every time a mistake is brought to my attention.
No corrections since last issue.
What am I doing to cope with the pandemic? This:
Watching: Silicon Valley
So, I’m going through the HBO back catalog and started watching the comedy Silicon Valley, only to discover that it is much, much better written than I expected. I thought it was meant to be kind of a goofy send-up of startup culture, similar to the film “The Internship” (with which it shares at least one actor), but it has turned out to be a lot more sophisticated than that. Yes, it has some extremely crude physical and sexual humor—but then, so does Shakespeare, so let’s not look down our noses.
In the first two seasons I have found it to deliver comedy that is unexpectedly layered. My wife described as “what The Big Bang Theory should have been,” and I think she’s right—this is a show where nerdy, intelligent people have a lot of misadventures but are generally made out to be sympathetic characters.
Looks like you all had busy weekends, so I’m light on comments this week.
You might have some questions or comments! Join the conversation, and what you say will impact what I talk about in the next issue. You can also email me if you have a comment that you don’t want to share with the whole group, or if you are unable to comment due to the paywall in today’s issue.
If you liked today’s issue, please consider becoming a paid subscriber and/or sharing this newsletter with everyone you know.
For those who won’t be continuing into the paywalled section below—as well as everyone who will—please know that I deeply appreciate having you as readers, and I’m very glad we’re on this journey together.
Always,
JS
