Interesting article about Long COVID. The part about 2/3 of those who identified as COVID long-haulers had negative Coronavirus antibody tests. I know those test are not prefect but 2/3 is a high number.
We need to start thinking more critically — and speaking more cautiously — about long Covid
Almost everyone who dies of Covid-19 develops a condition called acute respiratory distress syndrome (ARDS), a form of pneumonia involving severe inflammation of both lungs. Many studies have shown that for some individuals, ARDS can have myriad long-term effects, including physical and cognitive impairments, reduced lung function, mental health problems, and poorer quality of life. A 1999 study found that even patients with less-severe forms of pneumonia can have symptoms that linger for months.
In addition, lung failure can precipitate the failure of other organs, like the kidneys and the heart, and can sometimes require specialized rehabilitation and care for months, or even years. SARS-CoV-2 infection can also (though rarely) inflict permanent damage on other organs, including severe myocarditis (an inflammation of the heart muscle leading to heart failure) and stroke, in the absence of significant lung disease.
Still, even if these ailments are sometimes acknowledged in media reports of long Covid, most narratives evoke something entirely different: a debilitating syndrome seemingly affecting multiple organ systems for months on end — and perhaps indefinitely — but without any specific diagnosis such as myocarditis or stroke. It is also notable that reports often suggest that even those with only mild acute symptoms — or no acute symptoms at all — are at risk.
First, consider that at least some people who identify themselves as having long Covid appear never to have been infected with the SARS-CoV-2 virus. In Yong’s influential article, he cites a survey of Covid long-haulers in which some two-thirds of them had negative coronavirus antibody tests — blood tests that reveal prior SARS-CoV-2 infection.
Meanwhile, a survey organized by a group of self-identified long Covid patients that recruited participants from online support groups reported in late December 2020 that around two-thirds of those surveyed who had undergone blood testing reported negative results.
There's much more to the story than what is inferred from that statement, and I think you're making the wrong conclusion about post-COVID-19 Condition aka Long COVID. The first important point is that Yong wrote that article back in August 2020
. Back then, some of the antibody tests that were available were relatively poor in quality (some the FDA actually recommended discontinuing their usage
), and some ended up being discarded for low sensitivity and specificity. You can find the testing dynamics here
, and you'll see there's quite a range in performances.
Nonetheless, given the age of that initial report, there's been important studies that have been published that helps explain the phenomenon:
1) Patients with PCR confirmed COVID-19 lose seropositivity over time and depends on severity of disease
. In one study of patients with , by the six month mark, 28.7% tested negative for antibodies.
It has been a continued discussion going back to the end of 2020 of how long natural infection provides protection because antibody titers clearly wane.
2) Some of these cohorts of "negative" antibodies are biased by certain patient populations. In the study described by Yong, the majority of patients were women who had antibody testing on average 98 days after onset of symptoms
, and these were self-reports of antibody results using tests from 2020. Not only do some antibody tests suck, while others wane, but women are more likely to test negative
for antibody response to SARS-CoV-2.
3) Having antibodies vs no detectable antibodies increases the risk of having post-COVID-19 shown here
. However, in both studies, there were patients with post-COVID-19 symptoms and negative antibodies, despite having PCR confirmed disease up front.
4) However, those who develop more severe post-COVID-19 symptoms have a weaker antibody response than those who have more mild symptoms shown here
, suggesting the type and strength of immune response matters.
So there's much more to the story and the "2/3rds" number needs to be placed in proper context. Those patients he was citing didn't have serial antibody measurements (many antibody tests weren't even wide-spread until the summer 2020, and as mentioned, some sucked), so the kinetics of those patients he was describing is unknown. It is also hard to know if they seroconverted to undetectable levels. The newer research assays (as cited above) have a far higher sensitivity and gives a better viewpoint.
It is clear that long COVID-19 exists and occurs in many people. The exact percentage varies by study (in one review 4.7 to 80%), but people shouldn't be so callous to act like it doesn't exist just because the media tends to sensationalize it.