1. Out today, an important study about the characteristics of 37 asymptomatic COVID-19 infections from Wuhan. Patients were identified by screening close contacts of the cases; the authors made every attempt to exclude mildly symptomatic infections.
~40% asymptomatic and ~13% symptomatic cases revert to IgG negative in early convalescence. This does not imply they can be reinfected (still no established case of reinfection to date), but it raises serious questions on the value of serological surveys.
THREAD: This new Nature Medicine study which suggests some Covid antibodies may not last for long periods of time, doesn't mean people wont have residual immunity after infection. Moreover, other studies suggest there's a period of immunity for most people
Waning of SARS-COV-2–specific antibodies in symptomatic and asymptomatic individuals.
A cohort of asymptomatic patients infected with #SARSCoV2 had significantly lower levels of virus-specific IgG antibodies compared to a cohort of age- and sex-matched symptomatic infected patients. #COVID19 #asymptomatic #coronavirus #CQMU
8. In a recent paper from us, we found only 1 out of 44 mild (outpatient) cases after 21 days post onset that did not mount an antibody response. And all asymptomatic patients in another study mounted neutralizing antibodies.
New paper in () showing asymptomatic SARS-CoV-2 infected individuals mount lower antibody responses than symptomatic one. I buy that, but there is a weird discrepancy in the paper.....
On the importance of taking care in analysing real-time seroprevalence data. "Forty percent of asymptomatic individuals became seronegative and 12.9% of the symptomatic group became negative for IgG in the early convalescent phase."
The reduction in IgG & neutralizing antibody levels in the early convalescent phase might have implications for immunity strategy & serological surveys...these data might indicate the risks of using COVID-19 ‘immunity passports"
Covid19, buena noticia. Mucha gente que pareciera susceptible al virus no lo es, quizás porque tiene inmunidad cruzada contra otros coronavirus de los catarros. También hay personas que sin anticuerpos pudieran tener otro tipo de inmunidad que los protege.
Die Studie zeigt, dass 2/3 der Asymptomatischen Veränderungen in der Lunge hatten im Sinne einer leichten Lungenentzündung, obwohl junge Patienten. Das zeigt, wie aggressiv das Virus ist. Erstaunlich. Und trotzdem verschwinden die Antikörper sehr schnell.
Study of 37 asymptomatic #COVID19 cases & symptomatic controls. Asymptomatic cases: ➡ had liver and lung abnormalities; ➡ less likely to develop antibodies. ⚠️ Neutralising antibodies declined within 2-3 months in all - "immunity passports" are out.
A study in suggests people who have been infected with the coronavirus SARS-CoV-2 but never develop any symptoms of #COVID19 may have a weaker immune response to the virus.
1. New Nature study shows 2/3 of ASYMPTOMATIC #Covid19 seropositives had lung damage in 1 lung; 1/3 in both. 2. Brooklyn community was overall 47% seropositive; 61% in 16-20, 28% in 0-5 age groups. WEAR A MASK.
I found this interesting as well. "Abnormal radiological findings confined to one lung were identified in 66.7% (14/21) of the asymptomatic individuals" Keep in mind China used CT scans to screen for #covid19 because of high sensitivity.
This small study just out in reiterates what we already know: 1) significant number of infected people are asymptomatic. 2) the asymptomatic can spread #covid19. Thus, presume you're infected and wear masks, social distance, wash hands regularly
Clinical and immunological assessment of asymptomatic SARS-CoV-2 infections
Sobering news: long-term immunity of #COVID__19 asymptomatic patients is unclear; 'there are definite risks of using COVID-19 ‘immunity passports’', there is no substitute for prolongation of behavioral public health interventions via
3. So many studies have reported IgG, IgM but provide no insight on T-cell mediated immunity, no less serially assess this over time. A good example is this excellent recent paper in asymptomatic patients
Could use more patients, but this is stunning: 1. Asymptomatic patients (n=37) shed virus for longer than sympt patients (P=0.028) 2. 21/37 of asymptomatic patients had covid-associated lung abnormalities on their CT-scan
Clinical and immunological assessment of asymptomatic SARS-CoV-2 infections #GPHO
Seems like immunity passports will not be part of the package of tools we’ll use. Clinical and immunological assessment of asymptomatic SARS-CoV-2 infections | Nature Medicine
8 weeks after hospital discharge, 40% of asymptomatic patients have no antibodies, and 12.9% of those who were symptomatic had no #COVID19 antibodies. This has important implications for "immunity passports" ...
We may finally have an explanation of why many people infected with #SARSCoV2 don't get #COVID19 (i.e. are asymptomatic). Their immune system seems to say, stay calm and carry on, don't overreact: via
Does everyone infected with #COVID19 produce antibodies — and if so, how long do they last? Not very long (especially in asymptomatic), suggests a new study published in —>
Clinical and immunological assessment of asymptomatic SARS-CoV-2 infections | Nature Medicine
Clinical and immunological assessment of asymptomatic SARS-CoV-2 infections
Nature Medicine: Asymptomatic COVID-19 patients may have weaker immune systems
Can someone who knows about such things please convince me that the New York Times' summary () of this article () misses something important (beyond the small N)? And quick.
One published paper here in ... also suggests poor antibody response in asymptomatic individuals
Important new findings from 37 asymptomatic people with #COVID19 in ◆ Weaker immune response (IgG and cytokines) ◆ Median 19d of viral shedding ◆ 57% had CT abnormalities 40% asymptomatic & 12.9% symptomatic pts became seronegative ⚠️
Am I missing something, or is this news as bad as it seems at first glance re: duration of acquired immunity?
only a 37 patient study, but suggests that asymptomatic covid19 patients may only have immunity for a few months
Some troubling data around the risk of #COVID19 reinfection, especially for asymptomatic people who had the virus. New research in Nature shows asymptomatic people may be at risk of reinfection only months post-infection. This calls for more study. 1/n
3/ "...social distancing, hygiene, isolation of high-risk groups and widespread testing." No guarantee that antibodies to #COVID19 #SARSCoV2 actually provide immunity. Options for #pandmic control remain tough, and limited. No magic bullet solution, yet.
No clinical outcomes so should be taken with a few grains of salt but kind of depressing all the same.
Not much promise for “immunity passports” anytime soon. This study found that antibodies declined quickly (2-3 months) after COVID-19 infection.
“Forty percent of asymptomatic individuals became seronegative and 12.9% of the symptomatic group became negative for IgG in the early convalescent phase.”