Long COVID Stemmed from Mild Cases of COVID-19 in Most People

Yves here. I must confess I have not looked at the underlying multi-country study summarized in this post. Nevertheless, I thought the headline finding was worth promoting. First, there is still not enough known about Long Covid, so researchers should be encouraged by promoting work in the field. Second, as we have stressed, “Covid is mild” is misleading due to fact that those “mild” cases can produce Long Covid. On top of that, many who’ve had “mild” beg to differ with the label. There seem to be three categories: asymptomatic, mild, and hospitalized. You can be plenty damned sick and not wind up going to the hospital, and “plenty damned sick” seems to be the norm with Covid.

By Sarah Wulf Hanson, Lead Research Scientist of Global Health Metrics, University of Washington and Theo Vos, Professor of Health Metric Sciences, University of Washington. Originally published at The Conversation

The Big Idea

Even mild COVID-19 cases can have major and long-lasting effects on people’s health. That is one of the key findings from our recent multicountry study on long COVID-19 – or long COVID – recently published in the Journal of the American Medical Association.

Long COVID is defined as the continuation or development of symptoms three months after the initial infection from SARS-CoV-2, the virus that causes COVID-19. These symptoms last for at least two months after onset with no other explanation.

We found that a staggering 90% of people living with long COVID initially experienced only mild illness with COVID-19. After developing long COVID, however, the typical person experienced symptoms including fatigue, shortness of breath and cognitive problems such as brain fog – or a combination of these – that affected daily functioning. These symptoms had an impact on health as severe as the long-term effects of traumatic brain injury. Our study also found that women have twice the risk of men and four times the risk of children for developing long COVID.

We analyzed data from 54 studies reporting on over 1 million people from 22 countries who had experienced symptoms of COVID-19. We counted how many people with COVID-19 developed clusters of new long-COVID symptoms and determined how their risk of developing the disease varied based on their age, sex and whether they were hospitalized for COVID-19.

We found that patients who were hospitalized for COVID-19 had a greater risk of developing long COVID – and of having longer-lasting symptoms – compared with people who had not been hospitalized. However, because the vast majority of COVID-19 cases do not require hospitalization, many more cases of long COVID have arisen from these milder cases despite their lower risk. Among all people with long COVID, our study found that nearly one out of every seven were still experiencing these symptoms a year later, and researchers don’t yet know how many of these cases may become chronic.

Why It Matters

Compared with COVID-19, relatively little is known about long COVID.

Our systematic, multicountry analysis of this condition delivered findings that illuminate the potentially steep human and economic costs of long COVID around the world. Many people who are living with the condition are working-age adults. Being unable to work for many months could cause people to lose their income, their livelihoods and their housing. For parents or caregivers living with long COVID, the condition may make them unable to care for their loved ones.

We think, based on the pervasiveness and severity of long COVID, that it is keeping people from working and therefore contributing to labor shortages. Long COVID could also be a factor in how people losing their jobs has disproportionately affected women.

We believe that finding effective and affordable treatments for people living with long COVID should be a priority for researchers and research funders. Long COVID clinics have opened to provide specialized care, but the treatments they offer are limited, inconsistent and may be costly.

What’s Next

Long COVID is a complex and dynamic condition – some symptoms disappear, then return, and new symptoms appear. But researchers don’t yet know why.

While our study focused on the three most common symptoms associated with long COVID that affect daily functioning, the condition can also include symptoms like loss of smell and taste, insomnia, gastrointestinal problems and headaches, among others. But in most cases these additional symptoms occur together with the main symptoms we made estimates for.

There are many unanswered questions about what predisposes people to long COVID. For example, how do different risk factors, including smoking and high body-mass index, influence people’s likelihood of developing the condition? Does getting reinfected with SARS-CoV-2 change the risk for long COVID? Also, it is unclear how protection against long COVID changes over time after a person has been vaccinated or boosted against COVID-19.

COVID-19 variants also present new puzzles. Researchers know that the omicron variant is less deadly than previous strains. Initial evidence shows lower risk of long COVID from omicron compared with earlier strains, but far more data is needed.

Most of the people we studied were infected with the deadlier variants that were circulating before omicron became dominant. We will continue to build on our research on long COVID as part of the Global Burden of Disease study – which makes estimates of deaths and disability due to all diseases and injuries in every country in the world – in order to to get a clearer picture of how COVID-19’s long-term toll shifted once omicron arrived.

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  1. ambrit

    I noticed at the end that the author described the Omicron variant of the Coronavirus as “less deadly” than the earlier main variants. Is this part of a propaganda campaign to ‘influence’ the public to view the later Coronavirus variants as “safer,” and thus reinforce the ‘opinion’ that the endemicity of the Coronavirus is acceptable for the public’s health and safety?
    At this point, my “faith” in the public health apparat is gone.

    1. ChiGal

      that caught my eye too. what the vaccines DO seem to do is mitigate ICU admission and death, so not sure less death is down to the variants alone, although I am under the impression that Delta may have been the worst of the lot—so far. I could be wrong.

      1. Objective Ace

        Less death could also be attributed to survivorship bias. The population most susceptible to death (and/or infection?) had already died during prior waves

        1. Joe Well

          Mortality displacement or the “harvesting effect” is what you’re referring to, I think. Something that has not been given much consideration when discussing how lethal the new variants really are. It should in principle also mean less mortality from every other cause, and I think the fact that many causes of death are in fact rising shows how much secondary damage covid does.

    2. Realist

      When you think there may have been well over 300m infections in the US last year, the IFR was low, whilst the absolute numbers of dead and disabled was tragic.

  2. Jason Boxman

    As I’ve been saying since like 2021, we’re gonna find out how this goes by letting it go! What insane public policy, and a manifest evil.

  3. Roger Blakely

    What no one seems to be considering is that everybody is constantly inhaling SARS-CoV-2. SARS-CoV-2 is in the air in all indoor public spaces, especially the grocery store. The immune system is having to constantly fight off an array of variants. This virus is incredibly tenacious.This virus is off to the races the moment it hits mucous membranes, and it is incredibly difficult to clear from the body.

    1. square coats

      Totally using my lay person intuition here, but I think implicit in what you’re saying is how exposure to greater amounts of covid will generally cause someone to become more sick, right? So if people are frequently being exposed to even very low amounts, there might be some effect that isn’t being identified, or isn’t being identified as such.

      Kind of terrifying to think about, and also might help explain why so many people seem to be getting so much more sick these days from other bugs, in cases where they haven’t technically gotten covid (“technically” given this formulation). Anecdotally, as far as I know I haven’t had covid to date but I’m 99% sure I got absolutely whomped by RSV a few months ago, then had a significantly stuffy nose for well over a month after I otherwise felt fully recovered.

    2. Forrest

      There is nothing special about grocery stores among public spaces to theorize SARS-CoV-2 is worse there.

      1. Paris

        I also found it amusing how he picked grocery stores lol. Maybe he owns a business for online grocery shopping?

      2. Cassandra

        Well… Not everyone dines in restaurants these days; not everyone goes to movies or concerts. Many people have sworn off of airports and cruise ship vacations, where the density of pathogens is no doubt objectively worse. But *everyone* has to go to the grocery store (unless they can afford online food delivery services), so one can argue that grocery stores are a top exposure threat to vulnerable people.

  4. Lexx

    The fourth category is ‘perfectly healthy’. It’s the zero in ‘from zero to sixty’, the base from which we launch into discussions of positive yet asymptomatic, sick a little while, still sick long long time and unlikely to return to zero. The problem with having any confidence in being “well” is how we define and accept as fact ‘not well’. There’s a lot of sick in ‘perfectly healthy’.

  5. JustTheFacts

    The obvious question this raises for me is: were those who got long COVID from mild cases of COVID vaccinated?

      1. ChiGal

        this study suggests a 15% reduction in long covid for the vaccinated but is of limited value because it was apparently beyond its scope to factor in the medical histories (comorbities, immunocompromised status, etc) of its subjects.

        1. Objective Ace

          I’d also want to see variant type and how long since vaccine/booster incoporated into any reduction number.

        2. PNorde

          There are limitations to any study, the strength in this one may lie with the review of over 13 million subjects to make the 15% inference.

      1. ambrit

        That was what I was afraid of. Others have mentioned the probability that “being vaccinated” engenders a false sense of security, thus leading to the “vaccinated” engaging in high risk activities without prophylaxis.
        Of course, if one catches what is obviously the Coronavirus shortly after being “vaccinated,” the false sense of security will be severely degraded. Assuming that one recognizes the Coronavirus infection as such. The symptoms seem to be held in common with many other upper respiratory murrains.
        Stay safe, be on guard in this ‘Winter of Our Discontent.’

        1. José Freitas

          There is also emerging indications that vaccination also seem to make people more prone to infection, and to “tolerate” the virus (see the discussions around iGg4 antibodies in recent papers), as well as to prime them to fight a variant that is no longer in curculation (which helps deplete the immune system). This is not only worrying re. probability of variants emerging, but would also lead to think that the huge excess in deaths we are seeing come from long Covid that has been potentiated by vaxxed people (mostly) being constantly reinfected.

          Anecdotically, I know many vaxxed people around me who have already had 3, 4 or even 5 courses of Covid. Whereas most non vaxxed seem to have stopped at 1 or 2 (like me). Even if the vaxx protects somewhat against serious effects, especially in vulnerable groups, it may be spreading long covid far and wide.

    1. Old Ghotivst

      I came down with Covid in October 2022 (about a week after a visit to the Doctor’s office for a check up).

      I had an incredibly mild case. Felt fine in the morning. In the afternoon I felt tired, and took a 3 hour long nap. When I woke, I had a terrible sore throat, and decided to take a home covid test.. Which was positive.

      Called the MD on Monday, and was prescribed an anti-viral. However, because my symptoms were so mild, and I was fully vaxed and boosted, I decided to skip the anti-viral. My symptoms lasted all of 3 days.

      About 10 days after my positive test, I woke up with an incredible array of muscle and joint pain. On a scale of 0 to 10, the pain was a 25. In the past, I have had broken bones, and surgeries. But never had any pain like this. And never pains in these muscles and joints.

      The MD prescribed some tests, and meds. We ruled out gout, and blood work ruled out mineral deficiency. Muscle relaxants had no effect. But over the counter pain relievers like Aleve and Ibuprofin helped,

      Four weeks after the positive test, my body cleared the virus (two back to back negative tests). But the aches and pains persist (now 3 months in), albeit on a more bearable level, and I hope to completely recover at some point..

      Hope I am not over sharing here, but my BMI is 22 and I am in my 8th decade.

  6. Paul D.

    Does anyone know if there has been any advancement in viral load testing? I.E. Determining what the ball-park viral concentration is for a given measurement? This is very important, to me at least, because, from my training in pathology, how much virus (or any agent for that matter) is needed to result in high-probability of infection is very useful. Exposure does not (necessarily) equate to infection. A certain viral concentration is needed. Collecting this data for say, grocery stores, and other indoor public gathering spots might give scientists better data on methods of spread.

  7. Gusgus 2021

    I keep getting covid and each time I get pretty sick ,I am not fat or a couch potato either and work daily outside ,but each case seems worse the first time in 2020 it was pretty mild then I got it in 2022 and I had very serious coughs and could not breath .
    The last time I got to tired to move for a week,couldn’t eat for days and my hands kept going numb.

  8. SocalJimObjects

    I got Covid sometime back in October last year? Most of my symptoms like fever and sore throat went away within half a day to three days. I did experience a partial loss of smell that lasted almost 2 weeks and I also had a very light dry cough that similarly took around 2 weeks to go away. Thankfully I haven’t noticed any Long Covid symptoms. During my sickness, I was constantly popping that Chinese “wonder” pill Lianhua Qingwen, so maybe it helped? The drug did become the number one selling medicine in China after the reopening, https://www.scmp.com/business/china-business/article/3202687/stock-traders-pile-makers-cold-medicines-antigen-test-kits-chinas-shift-zero-covid-spurs-demand

  9. Ram

    COVID trajectory seems to be that of IBV in poultry. Non stop variants with poor vaccine protection across strains. Unless we find pan coronavirus vaccine we are heading for bleak future

  10. Anonymous 2

    I think a fourth category is useful : ‘moderate’, which sits between mild and hospitalised.

    My youngest daughter had what can fairly be described as a mild case of Covid recently which she described as less problematic than a normal cold (she tested, being a conscientious person). But then there have clearly been many non-hospitalised cases where people have been very unwell, just not so bad that they are accepted into hospital. These used to be categorised as moderate in the UK – perhaps they still are?

    ‘Moderate’ is of course the sort of euphemistic term doctors use which no lay person would consider accurate in the circumstances. Just as when describing a patient as ‘comfortable’ who almost certainly is pretty uncomfortable – just not in any danger.

  11. Mario

    My husband and I had a “moderate” case of Covid back in February of 2021 just as vaccines were becoming available. That is almost two years ago. We’ve had long Covid since, and it has been progressive. Extreme exhaustion on a daily basis is part of the “new normal” we now deal with, as well as weakness, braing fog, short term memory loss, and for me shortness of breath; lots of medical appointments and tests, too.

    By “moderate” (the term used a while back instead of “mild”) I mean we were really sick and barely able to function for six weeks, even though we were not hospitalized. I did receive a monoclonal antibody infusion a few days into my infection, when the pain in my throat and the cough I was experiencing were so intense I could barely speak. After two Moderna shots and two Moderna booster shots, I got Covid for a second time last summer and was pretty ill for ten days; one of those days I had a vasovagal syncope and collapsed.

    I’m terrified of getting Covid again, as more scientific studies show the virus weakens the immune system continuously. We had a fifth bivalent booster shot a couple of months ago, but it may be it offers us little protection against the latest variants.

    We are lucky to be enrolled in a Long Covid clinic in NYC at Mount Sinai under our Medicaid insurance. We are in a Long Covid support group that meets weekly. Three of our group members are young, and everyone in it is dealing with challenging medical issues.

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