Time Sensitive: If you live in California, Oregon, or Washington, and want to keep the mask mandate in healthcare settings, you can participate in West Coast Covid Action. (I know that some people in healthcare settings who wear masks now would stop wearing them in the absence of a mandate, and that this change would cause some deaths and disability from long covid which would otherwise not happen, and thus it’s worth fighting to keep the mandate, but given how hard it is already to find a set of doctors and nurses who follow the mask rules, not to mention that they often use leaky masks instead of respirators, I admit I’m dispirited about this).
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In this blog post, I said, “It’s possible that the last wave is over… but I won’t believe it until we go through a winter with low death and low hospitalization rates.”
Well, winter is almost over.
I didn’t define what I considered to be ‘low.’ I think what I anticipated was either a surge (like the Omicron wave in the winter of 2021/2022) or, if that didn’t happen, a clear decreasing trend. I can tell you I didn’t expect the plateau in covid deaths we’ve had for months (a plateau visible in both official covid death counts and excess deaths).
Since I didn’t anticipate this plateau, I lack ready explanations. I’m confused.
Given the people across the United States are reducing their use of masks and most people haven’t gotten the bivalent booster (and even those who have got it months ago, long enough for the immunity to fade), not to mention all the holiday travel, I would’ve expected more deaths than this. So something about my assumptions is off.
If covid were ‘over’, I wouldn’t expect a plateau this high either.
In my local area, wastewater covid levels were recently as high as they’ve ever been, not to mention we had a surge (measured in wastewater) last summer. I don’t watch national covid wastewater data as closely, but it seems that, excluding the Omicron surge of last winter, covid in wastewater is as high as ever. Though it’s difficult to calculate the number of covid cases based on wastewater data only (because different people shed different amounts of virus into their poo), the wastewater data suggests that plenty of covid transmission is still happening. So, the explanation for the plateau is unlikely to be that covid transmission is down.
(In this post, I say little about long covid because the data sucks. Alas, lack of good data doesn’t mean it’s not a major risk).
What about vaccines? Too much of the data which has come out in the past two years wouldn’t make sense if vaccines didn’t prevent some portion of covid deaths, so I assume they do. On the other hand, that portion is less than 100%, and vaccines weren’t enough to stop the surge in deaths in late 2021/early 2022. Is having even more booster shots reducing deaths to a lower level than during the first omicron surge? I can’t rule that out, but I doubt it given how much data shows that the immunity from boosters fades within months.
Are the bivalent boosters more effective than the original vaccines? I’ve seen mixed evidence for this (some evidence says yes, some evidence says they’re equal), but given how low a proportion of the population has gotten a bivalent booster, plus the effect of wading immunity, makes me suspect this isn’t the main explanation for the lack of a winter surge in deaths. Well, unless the people who took it were all the people who were most likely to die of covid, which isn’t a ridiculous speculation.
Did indoor air quality improve across the board? If so, I’d expect wastewater levels (reflective of transmission) to be much lower than what I see, since stopping transmission is how air quality improvements prevent death. But maybe, if death correlates with viral dose (and I recall seeing some evidence to that effect, though I’m not sure how strong it was) widespread improvements in air quality could reduce deaths without reducing transmission? My impression (based only on local anecdotal observations) is that some places have improved ventilation and/or filtration in response to the pandemic, whereas nobody has made indoor air quality substantially worse, but it’s chaotic and inconsistent.
What about paxlovid? I suspect that’s a partial cause of the plateau pattern, since it prevents deaths. Perhaps, in the absence of paxlovid, there would’ve been a surge in deaths this winter.
The only explanation I can think of for a plateau in deaths (as opposed to surge or plunge), is that most vulnerable people have already died, yet people become newly vulnerable all the time, and people in the population become newly vulnerable at a consistent rate, thus a plateau in death. Imagine that, at the beginning of the pandemic, a thousand people are at high risk of death upon infection. Within two years, 95% of them are dead, but each year, a hundred people join the high-risk-of-death group. This would lead to a pattern of high deaths in the earlier years (perhaps in various surges) followed by a plateau which was well above zero.
In the real world, people are low-or-high risk in complicated ways. An immunocompromised person in fragile health might be low risk if their life is structured so they’re never exposed to covid, likewise, a 20-year-old in apparent good health may have an unknown genetic vulnerability.
One concern I have is that repeated infections seem to do lasting damage to the body, such that someone who had low risk of death at the first infection may be at high risk of death at the fifth infection.
Now, let’s tackle the question of masks. Because of my personal experience, I believe that N95 respirators are good at protecting the wearer from covid infection BUT they don’t reduce the risk of covid risk to zero, especially in cases without other protections. The other day, I read about someone who had diligently worn their N95 at their office job, but the office was poorly ventilated, nobody else wore a mask, the coworker who was at the nearest desk came to work while infected with covid, and infected the person who had always worn an N95. Assuming this person couldn’t get a comparable job in safer conditions, I believe they did all they could, and that if their employer and coworkers had taken minimal precautions to prevent transmission (such as NOT COMING TO WORK UNMASKED WHILE INFECTED WITH COVID), the N95-wearer wouldn’t have gotten infected.
In the local wastewater data, yeah, I can see some correlation between people refusing to wear masks in grocery stores and an increase in transmission. Perhaps averaging data across the entire United States obscures patterns like that, especially if mask wearing increases/decreases at different times in different communities. However, more unmasked people in indoor public places don’t seem to have increased deaths in recent months. Perhaps this is a decoupling in transmission and deaths, not evidence that masks don’t reduce transmission.
So, where does this leave me? Well, confused. I’m not sure the explanations I suggested are the correct explanations for this plateau in deaths. Throughout the 19th and 20th centuries, many societies increased life expectancy by incapacitating infectious diseases such as cholera, measles, tuberculosis, smallpox, etc. We’ve enabled a new infectious disease, thus our collective life expectancies are lower than they were in 2019.
The future of covid depends much on how new variants mutate and evolve. I wouldn’t place bets.
The Notes Which Do Not Fit 