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A modeling study on the new coronavirus  warns that intermittent periods of social distancing may need to persist into 2022 in the United States to keep the surge of people severely sickened by Covid-19 from overwhelming the health care system.

The research, published Tuesday in the journal Science, looked at a range of scenarios for how the SARS-CoV-2 virus will spread over the next five years. Those scenarios included variables like whether people who are infected develop short-term immunity — less than a year — or longer-term protection. But, overall, the research concludes it is unlikely that life will return any time soon to the way it was before the virus’ emergence.

The researchers, from Harvard University’s T.H. Chan School of Public Health, acknowledged the economic fallout from the response to the virus has been profound. And they stressed they were not advocating one course of action over another.


“Our goal in modeling such policies is not to endorse them but to identify likely trajectories of the epidemic under alternative approaches,” they wrote. “We do not take a position on the advisability of these scenarios given the economic burden that sustained distancing may impose, but we note the potentially catastrophic burden on the healthcare system that is predicted if distancing is poorly effective and-or not sustained for long enough.”

The authors suggest a number of factors will play a major role in the path the disease will take over the coming years — if transmission subsides in summer and resurges in winter, if there is some immunity induced by infection and how long it lasts, and whether people get any cross-protective immunity from having been infected with related human coronaviruses that cause common colds.


In terms of the latter, they suggest if infection with the human coronaviruses, HKU1 and OC43, gives some protection again SARS-CoV-2, it could appear that transmission of the new virus was tapering off. But a return within a few years would be expected, perhaps by 2024, they suggested. The two human coronaviruses induce only short-term immunity — less than a year — in infected people.

If SARS-CoV-2 triggers immunity of a similarly transient nature, annual wintertime waves of infection might be expected, they said. If the immunity lasts longer, the time between surges of cases might be a couple of years, or more.

And if immunity is permanent, the pandemic might burn itself out by about 2025, they said. The researchers suggested, though, that that scenario is unlikely.

The model predicts that a one-time social distancing effort of the type currently being employed in most parts of the country will not stop transmission of the virus. If treatments are developed that can prevent Covid-19 patients from progressing to severe disease or if a vaccine is developed, movement restrictions could be loosened without health care capacity being overwhelmed, the researchers said.

Likewise, increasing the capacity for intensive care beds could also allow a community to loosen its restrictions, as long as it could cope with the severe cases the increased spread would generate. That could speed progress towards herd immunity — the point where enough people have some immunity that transmission should drop off, they said. Without these extra tools, though, transmission will resurge once controls are loosened, the authors warned.

“So I think distancing interventions of some sort are going to have to continue, hopefully lightened and in conjunction with other interventions,” said Marc Lipsitch, a leading infectious diseases epidemiologist and senior author of the study.

Infectious diseases epidemiologist Caitlin Rivers said the modeling work will be useful for public health officials and disease experts trying to plan for the continued response to the virus.

“What this is saying is that SARS-CoV-2 will stay with us through 2022, that it’s not going to die down to nothing in the summer. So I think it’s helpful for thinking what interventions are sustainable and effective,” said Rivers, an assistant professor of epidemiology at the Johns Hopkins Center for Health Security. “If we knew that we only had to make it through another two weeks, we might make different decisions than understanding that this is a threat that will be with us for many months,” she added.

While acknowledging that intermittent periods of distancing over several years “is obviously a very long time,’’ Lipsitch said loosened restrictions could come sooner if scientists discovered that a lot more people have been infected already and have some immunity. He and his co-authors stressed how critical it is to conduct long-term serology studies designed to map out human immune responses to the virus over time.

“On the other hand, there are some indications coming out at the moment that not every case of Covid-19 infection … generates a robust immune response, which would mean that the build up of herd immunity is slower than its anticipated here,” he added.

The study does not look at whether imposing social distancing only among certain high-risk groups — including older adults and those with serious underlying health problems — might keep the number of severe cases low enough that health systems would be able to handle them.

Another of the authors, Yonatan Grad, said tailoring restrictions to high-risk groups would be an important idea. But one would also need to factor in whether people who had been freed from social distancing restrictions would then interact with people in those restricted groups — something that might depend on the composition of individual households, he said.

Lipsitch acknowledged that delaying the development of herd immunity — effectively keeping large numbers of people susceptible to the virus by shielding them from infection — runs a risk of creating a larger wave of illness later, if controls are eased during a time when the virus transmits more easily, as it is expected to do during winter months. But delaying infections buys time, he said.

“Pushing bad things out into the future is something we want to do because we should know more about treatments, we may be closer to a vaccine,” he said. “So there is some benefit to delay, but it might be offset in the seasonal scenario where we push the peak into the high transmission time around the winter.”

  • So just so I understand, we are supposed to forego work, school, weddings, funerals, church, parks, etc etc etc for 2+ years so we can all stay alive?

    At what point would the life become no longer worth living?

    • In another few weeks we will have much more protective gear available. That, by itself, will make it safer to venture out. I am personally hoping a wearable backpack/helmet combo to filter air, and pump it into the helmet, so that there is positive pressure in the helmet and it is pretty safe to be around other people while you wear such a device. I think such a thing could be manufactured and sold at a profit for under $1,000 and that, if we are looking at 2 years to get a vaccine, it is the only way to get back to some normality.

    • Your Comment might make some sense if you could show any evidence a very small number of people would die.
      The raw death rate so far is 4%. 20,000 deaths divided by 500,000 cases. If we do not have anything better to offer, we would need to wait for 160 Million to get infected, meaning maybe 6 Million die, to get back to normal life for the rest of us. Hopefully, we will get some very serious protective gear in a few months, and be able to get back to semi normal life.

    • @Steve White: That number is in the USA, where it’s easier to get a test if you’re a tiger in the Bronx Zoo than if you’re at a doctor’s office. In countries that have tested extensively, without any exception, death rates have been below 1%. Germany. Iceland. South Korea. All around 0.6%.

      Stop being scared by America’s crappy statistical situation!

      A few credible counterfactuals:

    • @Steven Wright….do some research into the flu death total of last years seasonal flu. Yes, this little beer virus is deadly…to elderly with health problems and non elderly with respiratory problems. Don’t ask people to prove anything. If you’re intelligent enough, you’ll research and prove it to yourself. Time to be a Big Boy now.

    • Frank – I do not think you actually look at the evidence. As best i can tell by reading your posts, you have some political attitudes which control your perceptions about this.
      If I see clear evidence, actual evidence, not what seems to be mostly wishful thinking, that a great many infected people are undetected in the US, then I will change my mind. There is a study from Stanford attempting to determine how many people in that area – which has a pretty high number of cases – have antibodies to the virus. They are saying they will have some results very soon. One of the researchers was on Tucker Carlson saying he did not yet know but he currently suspects a much lower death rate.
      I will wait to hear what they have to say, but honestly, I do not see China shutting down an entire region for something which was not very, very bad. Of course their death rate was for people who apparently not only did not get medical help, but were not mostly not allowed to help themselves as best I can tell, but still it was in line with our raw data to date.
      I fully understand we have very inadequate testing and there are a lot of sick people who did not get tested, but because a lot of the tested people were recently infected, many have yet to die, so that will add to the rate.
      About your claim the only younger people getting sick have lung problems – that would be great for me, I never smoked regularly and never had a lung problem – but a very recent study using AI found that next to age, obesity was the biggest risk factor – thought to relate to metabolic syndrome, inflammation, cytokine storms- anyway, there are a lot of obese people in the US. And many are not old.
      There is one more problem with calling this a “flu” – as a NOVEL virus, the effects of this thing are simply not known, but one effect already noticed is that it infects the heart, and this may be fairly common in severe cases, and so it appears there may be, among people who recover, a very high level, (compared to the “flu” ) of people who end up with permanent disability after they recover. Damaged hearts which will prevent them from doing a lot of things. The disease does damage to other organs too. So, the death rate is only part of it.

      I very much hope you are right it is not as bad as the raw data say, but we need to look at people who are, without any question, at least six weeks post infection.

    • It’s not a flu (influenza is a totally different kind of virus).

      However, China’s action doesn’t mean they know something we don’t; China dealt with SARS, so they were primed to react strongly. (And the earliest cases in Wuhan were showing a notably higher, SARS-like, raw CFR.)

      It does seem clear that populations with better testing show lower raw CFRs.

      I don’t have the expertise (either in health or economics) to form an useful opinion on where to go forward from here, but let’s be clear as to what the statistics we have now do and don’t show.

    • I realize this is not a flu, or maybe you were responding to someone else who calls it that..
      I do not feel certain, but I think China’s government is acting like they feel confident they can either entirely prevent, or else keep a lid on, any new outbreak of the virus. Maybe they do not know anything we do not, but it seems like they do. I think they sent in people to sample all the animals in the market in Wuhan and found out what animals were carrying it, and have taken those off the market without telling us. But that is just a theory. Another theory is they have a vaccine already. By experimenting on prisoners, without regard for their safety, beginning some time in the middle of the big Wuhan outbreak,
      they may already have something which has been proven to work by challenge with the virus after 3 weeks or so. Depending on when the virologists were brought in and actually allowed to do their work, they may have been working on it for 5 months by now.
      But, I admit that is all speculation.
      I do hope the case fatality rate is way under 3% but I see no reason to think so – the one Chinese study which got reported before the lockdown on research said 4.5% for men, I have heard of no good reason to think it was wrong, or will be much lower here.

    • Steve, in all seriousness, i don’t believe one thing MAN types, writes, or says knowing his past. All MAN does and has done with his time here on earth has been to kill himself, lie, cheat, steal, and kill the planet in the name of greed. We are actually the VIRUS running amuck here destroying everything.

  • The fact is we don’t know exactly what is working or not…may be hurd immunity! But we do know….lose weight….possibly start smoking…all conjecture at this point. Hopefully some day, some analysis from “astute statisticians and Fauci’s” will explain….not use surrogates!

    • I must disagree with your claims. The raw case fatality rate where you divide deaths attributed to a coronavirus by known cases, is about 4%.
      20,000 deaths/500,000 cases
      The claim is, there are a huge number of people infected but not diagnosed who are not dying and and so the number of actual cases is much higher than the number of cases proven by testing.
      There is no doubt at all the number of cases given in CDC stats is far too low – but it is not typically mentioned that the number of deaths may climb a great deal, even if no new people get sick at all.
      The reason is, unlike many infections, it seems to take a long time to die of this disease. About 4 weeks on average – so if you wanted to know the true death rates for infected people, you have to figure out how many were infected a month back.
      That number is hard to get, but it is pretty clear any reasonable projection, where the virus was expanding exponentially, leads to a very high death rate.
      Right now there are 500,000 people proven to have been infected by testing.
      If that number were the actual number 4 weeks back, the case fatality rate would still be 4%. But, depending on how bad the testing is, how many cases are missed, we would expect the actual number 4 weeks back to be much, much lower than those who have tested positive as of today.
      We were told the case fatality rate was estimated to be .6% in America, but for that to be true, if the “four weeks average time from infection to death” is also true, we must have had about 100/.6 = 160 160 x 25,000 = 4 Million people sick 4 weeks back.
      Or make it a case fatality rate of 3% – and you get only 1/5th the infected people back then – still 800,000 people -more than identified today. It could be true but there is no evidence for it.

      The fact is, the numbers are very bad. Five percent may be far too low.

    • Andrew, it will only stop when all freedoms have been taken, along with all weapons (GUNS) that can be used to fight against this attempt at their New World Order. Its not to difficult to understand the greed of powerful humans.

  • When you read the article from Science, you’ll see that it seems pessimistic about the development of a vaccine: “A vaccine would accelerate the accumulation of immunity in the population, reducing the overall length of the epidemic and averting infections that might have resulted in a need for critical care.”

    My reading of that statement is that they assume that if a vaccine is developed, it will not be widely distributed or very effective.

    • Yes Rasmus, many Coronaviruses don’t generate long lasting immunity, and in many cases vaccines have made patients worse, not better. This happened for example with a test vaccine for the common cold. Even if we can develop a vaccine, it might be more like 5-10 years away than 18 months. Despite us knowing this, there are many like David below who want to plug their ears and not hear that we are going to have to deal with this head-on, that it almost certainly will not be possible to hide out and wait for a vaccine to appear.

    • Some states and countries will soon discover that a fortune can be made in the absence of restrictions. Hotels, casinos, bars, clubs, concerts, restaurants: keep them all open 24/7. The local population will be either immune or dead. Party like it’s 1999!

  • I’m thinking that we should create a colony on the moon where we can quarantine people, NASA should be able to construct that by August or so I’m thinking. We need to stay safe!

    Oh what’s that? That’s a crazy, wildly impractical solution? Well, guess what this current ham-handed quarantine is? Expecting this to last until 2022 is just dumb.

    Stat should start a “From the halls of academia” section where we can dump all of these absurd “If coronavirus and the entire world’s population existed in a flask where we could control everything” papers, where we could all go to have a laugh. At some point, doesn’t common sense have to come into play in all of these models? What good is a model if the underlying assumptions are completely ridiculous?

    • Have you considered the possibility the underlying assumptions are not being stated publicly?
      What if the case fatality rate is 5% or more, and they knew that but did not want to tell us?
      What if they knew very early on it is was easily, EASILY transmitted by air?
      If those two things were known, and used as the basis for what do, the lockdown makes a lot more sense as a response, it is not excessive, it is really too lax, as they did not tell use to use face masks, or stay more (MUCH MORE) than six feet apart.
      What if they

    • Hi Steve,

      I work on the data available.

      I will say that there are empty hospitals, ships and unused ventilators all over the country right now though. Cuomo 2 weeks ago was discussing 26,000 vents that he needed to prevent certain disasters and the need has been nothing close to that. And don’t give me, “Oh the quarantine has worked better than we thought!” because those projections were with social distancing. My thoughts are much more that this is and continues to be typical ham-handed government thoughtlessness leading to unrealistic and downright dumb maneuvers that are going to hurt us in the long term than it is that there is a vast conspiracy to keep the “real” numbers from being published.

    • Hi David,

      What a pointless comment. 1. You have no clue of who I am or my background and 2. Like it or not, this country isn’t run by epidemiologists and is a democracy, not a tecnocracy. Believe it or not, there are concerns that are going to need to be balanced in this situation other than purely those of the virus. I understand you’re likely sitting at home, frightened of what you’re watching on the news. I also suspect you have a job that you feel secure in… many people do not and are currently wondering where food, rent and their family’s futures are going to be paid for from. If their kids are going to be hungry. If they are going to be evicted from their homes. Like it or not, those people’s feelings and views are valid, even if they don’t have 7 years of studying a very specific field.

      Before commenting I suggest you try to understand other people’s viewpoints, rather than trying to be a keyboard tyrant and shut down those viewpoints you don’t agree with. Regardless, you, the government and all of the king’s men are not going to be able to keep the current processes in place much past May.

    • I have no idea what the long term right thing to do is, but @Steve White, we know the true case fatality rate is not 5% or more. I know not everyone trusts the China data, but look at South Korea, Iceland, etc. which have better testing and lower fatality rates, and both of which have peaked (so the fatality rate is not too far off).

      There’s too many different countries involved for a ‘hiding information’ narrative to be at all plausible at this point.

    • I asked “What if the CFR is 5% ? ” in response to Robert’s “What good is a model if the underlying assumptions are completely ridiculous?” = which question he never justified by undermining ANY assumption made in the models, as best I can see.
      The true CFR could be 5%. The raw data available from CDC indicates 4%, as deaths are around 20,000 and known cases are 500,000 – so 20/500 = 4%

      The claim is made that there are huge numbers of undiagnosed people who do not get very sick, so that the 20,000 deaths must be divided by millions of infected people. I certainly hope that is true, but the Wuhan study indicates that was likely NOT true there, when a huge number of tests were given to people who suspected they were infected and only a small percentage actually were.

      There actually might be some people who died, and that was not attributed to coronavirus, but also, a mathematical reason- it takes only a few days for a person to get contagious. And less than 2 weeks for them to recognize they are sick – the number of people with no symptoms is less than 25% .
      But it typically takes around 4 weeks to die of the virus. That means, while the undiagnosed people could be a big factor to lower the CFR, the number of infected people, who are recently diagnosed and have not yet died, is going to RAISE the CFR.
      While the number of cases is rapidly rising, as it is right now in the US, the percentage of people who are recently sick, and still alive, is deceptive. What you need to do, to guess at the actual CFR, is look at how many people were infected about 4 weeks ago, and divide the number of fatalities by that number:
      deaths due to coronavirus/number of people infected about 4 weeks back
      Both numbers are being debated but if the number of infected people was 1 Million – A MONTH AGO – even though we only have 500,000 identified now – think about that – even though the travel ban came on Jan 31, they did not know there were 1 Million a month back? That does not make sense really, though i can not say it is impossible, it would show a terribly inadequate public health response – even if that were the number, it is still A 2% DEATH RATE.

      If there were 400,000 infected people a month ago – in other words, something like 100 times the identified cases back then – that still goes to a 5% death rate if the survival time is 4 weeks.

    • If we had only US data to look at, a real CFR of 5% might be believable. But Iceland, South Korea, the Diamond Princess etc. show it is not.

      “While the number of cases is rapidly rising, as it is right now in the US, the percentage of people who are recently sick, and still alive, is deceptive.”

      That principle is correct, but the US appears to have already peaked (about five days ago) so it doesn’t seem to apply here.

    • The Sky IS Falling….Must be due to Climate Change!
      The Institute for Health Metrics and Evaluation at the University of Washington with about 500 statisticians, computer scientists, and epidemiologists on staff, IHME is a data-crunching powerhouse. Every year it releases the Global Burden of Disease study—an alarmingly comprehensive report that quantifies the incidence and impact of every conceivable illness and injury in each of the world’s 195 countries and territories.
      On April 8, IHME reduced the total number of hospital beds it had predicted would be needed nationally by a remarkable 166,890 — down to 95,202 from the 262,092 it had predicted less than a week earlier (i.e., it was nearly two-thirds off).
      The ICU projection over that same week was cut in half: to 19,816 on April 8, down from 39,727 on April 2nd.
      The projected need for ventilators also fell by nearly half, to 16,845 from 31,782.
      For this year, the CDC projects that flu deaths will range between 24,000 and 63,000, and that hospitalizations could surge as high as 730,000 (out of the 18 to 26 million people who are treated for flu, out of as many as 55 million Americans who experience flu-related illnesses). We don’t shut the country down for that.
      Specifically, officials pointed to a computer model released weeks earlier by Imperial College London that, at the time, predicted that if no action were taken to slow the spread of the virus, about 2.2 million people in the United States would die over the course of the outbreak.
      Last evening Mother Tucker of Fox, gave good, relevant, impactful data rather than the meaning less numbers we’re so accustomed to seeing from Johns Hopkins and others of which deaths is the only hard number, the rest being skewed by likely, the same IHME statisticians gave us….likely unemployed pollsters from 2016 Presidential Election.
      • 98% of New York’s deaths had comorbid conditions
      • 3% were less than 45 years old
      Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, (NIAID) has revised his original prediction that between 100,000 to 240,000 people would die in the United States due to the coronavirus pandemic. Dr. Fauci, according to NPR, now believes that it “looks more like 60,000 than the 100,000 to 200,000” deaths from COVID-19 that were originally forecast.
      On March 16, one scientific report claimed that without action, social distancing and stay-at-home orders, 2.2 million Americans would die from the coronavirus. The new 60,000 number is just 2.7% of that original dire prediction.

      “I think Tony is playing the same exact role that he has in the past — to make sure the science is accurate and clear,” Ms. Shalala said. “During a health emergency, it’s the scientists and physicians that are the credible people to the American public, not politicians.”
      And Dr Fauci continues with his esteemed thought process downgrading efficacy of hydroxychloroquin as the trials are not in yet. In a true clinical trial there must be at least a placebo arm/standard of care, to assess overall value and impact on economics, quality of life, adverse events for both arms. Is he looking responsibly at this trial….remember Dr Fauci….DO NO HARM! It’s only peoples’ lives that survived COVID 19!

    • @bud

      What is your point?

      That models have improved as more data has been collected? Yes, no one is arguing about that. Epidemiologists (and anyone else who makes models) will be quick to tell you that a model is only as good as the assumptions that go into them. If they are trying to deceive/scare people with inaccurate models, why do they keep updating the models?

      That social distancing is working? Yes. I’m certainly glad that we are not on pace for 2.2M deaths in the U.S.

      That COVID-19 isn’t as bad as the flu? Or is it “only” as bad as the flu? If all of the (very delayed) social distancing we have undergone STILL leads to 60K deaths in the U.S., I call that a pretty serious disease.

      If anyone is fear-mongering, it is people like you who seem to be implying that there is some sort of widespread conspiracy being perpetrated by epidemiologists and public health officials (a classic existential threat to peace on earth!) who really want everyone to stay inside for no reason at all.

    • David – I am curious, what do you think of the CDC telling us the case fatality rate (CFR) would decline greatly, to under 1%, based on an assumption there were huge numbers of people who had been infected by not identified as infected, while one study from Wuhan was reported to show the CFR was more like 3%, and Bruce Aylward of WHO said there were only small numbers of people not found.? It seems like wishful thinking, considering especially that the SARS CFR was about 10%. I think they called for the shutdown because they were not sure but feared the much higher CFR and thought it was better to try to buy time for research, in the hope some good medicine could be found and produced.
      IMHO – they screwed up in a very important way – they need to scare the hell out of the public here in the US and failed to do that.

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