Light at the end of the pandemic tunnel?


Sometimes it seems like this pandemic will never end. We have been teased in the past that things were looking up, especially early in the summer when vaccinations were being rolled out and the numbers of Covid-19 cases, hospitalizations, deaths started decreasing. But then the Delta variant kicked in and we went back into mask-wearing, physical-distancing, and hunker-down mode. Or at least some of us did.

But now a respected team of scientists who form the COVID-19 Scenario Modeling Hub that advises the Centers for Disease Control and Prevention say that the worst really may be over and that their models, under varying conditions, predict that we should start to see declines lasting all the way through March of 2022.

For its latest update, which it will release Wednesday, the COVID-19 Scenario Modeling Hub combined nine different mathematical models from different research groups to get an outlook for the pandemic for the next six months.

“Any of us who have been following this closely, given what happened with delta, are going to be really cautious about too much optimism,” says Justin Lessler at the University of North Carolina, who helps run the hub. “But I do think that the trajectory is towards improvement for most of the country,” he says.

The modelers developed four potential scenarios, taking into account whether or not childhood vaccinations take off and whether a more infectious new variant should emerge.

The most likely scenario, says Lessler, is that children do get vaccinated and no super-spreading variant emerges. In that case, the combo model forecasts that new infections would slowly, but fairly continuously, drop from about 140,000 today now to about 9,000 a day by March.
Deaths from COVID-19 would fall from about 1,500 a day now to fewer than 100 a day by March 2022.

Given that we are all a little wary of becoming too hopeful, the authors of the study are careful to point out the sources of uncertainty.

And this scenario projects that there will be no winter surge, though Lessler cautions that there is uncertainty in the models and a “moderate” surge is still theoretically possible.

There’s wide range of uncertainty in the models, he notes, and it’s plausible, though very unlikely, that cases could continue to rise to as many as 232,000 per day before starting to decline.

“We have to be cautious because the virus has shown us time and time again that new variants or people loosening up on how careful they’re being can lead things to come roaring back,” Lessler warns.

At this point, I am grateful for any signs of improvement.

Of course, if this model proves accurate, we will still be faced with how to decide if and when the pandemic is ‘over’ and we can let our guards down. It is highly unlikely that there will be a clean drop to zero infections and deaths. We will have to calibrate how low the numbers must get before we treat it as effectively zero, the way we do with other infectious diseases like the flu, and treat the risks of getting infected the same way we treat the other risks of daily life.

Comments

  1. flex says

    I have been wondering about this, from a periodic oscillation standpoint.

    A system which is experiencing periodic oscillations, and lots of systems do, is generally unstable over the long term. The system can reach a state where it collapses, breaks down, or the periodic oscillations will decay over time. To maintain a stable oscillating system requires active control of all the parameters which can influence the system, because a drift of some of even the minor parameters can move the system into an unstable state. When I studied the mathematics of soliton waves a couple decades ago I was fascinated by a waveform which is designed to be self-reinforcing, but even with soliton waves minor differences in the medium will eventually destroy them.

    Many systems show periodic oscillations, and the ripples of a disease through a society can be viewed as such. Even extremely virulent diseases, which kill themselves by eliminating most of their hosts before the host can transmit the disease, result in a huge immediate impulse function, but a series of dampened peaks over time. It can hardly be otherwise until a disease comes along which kills 100% of the people but only after the disease is transmitted to other hosts. Generally though, the initial wave of a pandemic is not as bed as the second wave, because while a certain amount of fear is generated by the first wave, it usually affects less people and disease is more likely to be seen as transitory so few restrictions are placed on people’s movements/actions. Which amplifies the oscillation for the second wave.

    Of course, the peaks of any oscillation can be affected by the parameters. In the case of a disease like COVID, wearing masks, self-isolation and quarantine, as well as improved hygiene clearly helped dampen the second wave. Which is most likely why this current oscillatory peak is higher than we would expect, those measures taken to dampen the second wave are no longer being followed assiduously.

    But that doesn’t stop the periodicity and dampening affect of epidemic progression. That is, we are likely to see COVID peaks until the disease becomes part of the background disease load for society.

    The above study is interesting, but I wouldn’t be very surprised if after a trough of 9K cases/day it increased during next summer (or possibly fall) to 25k-30k cases/day. Then dropped for awhile until another peak is reached a 15k-20k cases/day. The disease isn’t going away, and since inoculation doesn’t prevent 100% of infections before COVID can become transmissible, the odds are very good it will never be completely annihilated.

    BTW, if I was ever going to teach a High School course in math, the periodic oscillation waveform is one of a few waveforms I would teach in depth. Like the Binomial distribution or the S-curve, it shows up so often in so many disparate phenomena that students should be able to identify when it occurs in nature, economics, medicine, psychology, control theory, etc. Students should know what the data looks like and how to identify whether it is dampening or destructive.

  2. brucegee1962 says

    One figure that I’m curious about would be how many of those who are unvaccinated, get sick, and survive, then go on to get the vaccine. Since we know that the vaccine provides better protection than previous illness, finding out how bad the sickness actually is may be the only way to get through to some idiots. Is that working, or are they crawling out of the hospital and still refusing to get the shot?

  3. Reginald Selkirk says

    There are many interesting and tricky aspects to such modeling. A big one is that human psychology is involved. I am glad to see that they discussed such complications.

    It is interesting to read that they included the possibility of new variants. The evolutionary pressure on variants would be towards increased spreadabilty and/or escape from the current vaccine coverage.

    One thing that dismays me is the number of “breakthrough” infections of vaccinated people that helps to continue the spread. One potential remedy for that is nasal vaccines.
    Vaccine nasal sprays aim to ‘shut door’ on virus
    There is discussion of third or booster shots. I would feel better about those if they had some novelty to them, such as better coverage of delta and other variants. But of course that would take time to develop, and by then even newer variants might appear.

  4. brucegee1962 says

    The main problem with booster shots, imo, is that from a global perspective, the limited supply of vaccines that get made from now on will do more good for the unvaccinated than the already vaccinated. If people in the west say “Nah, we’re good,” then we need to be shipping them to countries that actually want them as quickly as possible.

  5. mnb0 says

    “At this point, I am grateful for any signs of improvement.”
    Confirming that you are as capable of self-deception as every human being.
    The model only uses American data and hence only applies to the USA and assumes the country is perfectly isolated.

    Worldwide somewhat less than 45% has been vaccinated at least once.
    Lots of opportunities for the virus to mutate. Wait long enough and the entire shenanigan starts over again.
    Unless the USA, the EU and China finally become sensible and do what they promised already a long time ago. But thus far it has been America/Europe first.
    But hey, enjoy your gratefulness now you still can. I don’t, I’ll stay safe. See, in Suriname about 0,15 percent of the population has died from Covid. That would be 450 000 covid deaths in the USA. Racists should be grateful too.

    @4 Brucegee: spot on. It’s even in the interest of the rich countries.

    https://ourworldindata.org/covid-vaccinations

    Nigeria: 214 million people, 2,1% vaccinated.

  6. John Morales says

    mnb0:

    Confirming that you are as capable of self-deception as every human being.

    Nah, it doesn’t “confirm” any such thing. It just means you personally either don’t believe it’s a sign of improvement or don’t think one should be grateful for such.

    (Also, that you imagine each and every human is as capable at any given thing as any other human is kinda cute; in reality, people differ)

  7. says

    John:

    Also, that you imagine each and every human is as capable at any given thing as any other human is kinda cute; in reality, people differ

    Oh, come on, John! That’s a bit absurd and you damn well know it! Well, to be blunt, you’re beating up on a strawman by taking “every” quite literally. Sure, you can probably find a handful of people who aren’t capable of whatever the claim is. That’s not falsifying the claim because it should be well understood that “every” should not be taken literally and should be charitably interpreted more like “the vast majority.” If I were to say “You are as capable of breathing air as every human being,” you could absolutely point to COVID-19 patients on ventilators and “falsify” my claim. But, if we’re being honest, almost every human is capable of breathing air, are they not?

  8. John Morales says

    [OT + meta]
    Leo, addressing my parenthetical aside:

    That’s not falsifying the claim because it should be well understood that “every” should not be taken literally and should be charitably interpreted more like “the vast majority.”

    Heh. So why are you taking me literally? 😉

    But, if we’re being honest, almost every human is capable of breathing air, are they not?

    To a greater or lesser degree, sure. But, you know, emphysema and that.

    That is, everyone is capable at breathing air, but some are less capable than others; even in your example, the claim “you are as capable of self-deception respiration as every human being” would be misleading, when addressed to someone without compromised lung function, since they would be more capable than some others.

    And, you know, Mano is not a goddist. So right then and there he’s not as capable of self-deception as those people are.

    More to the point, in my estimation, mnb0 is generally a drive-by accusative contrarian niggler, and I’m more than happy to contend with them. I do wish they would attempt to engage, it would be fun.

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