Schlagwort-Archive: covid19

Virus reactivation

A recent Nature study showed Ebola reactivation in a previously infected patient:

The 2021 lineage shows considerably lower divergence than would be expected during sustained human-to-human transmission, which suggests a persistent infection with reduced replication or a period of latency.

The most recent viral genome shared 10 substitutions that evolved during the previous epidemic making it unlikely that there was a new animal spillover event. I always wondered how second & third wave of COVID-19 started in Germany. Was it really a new spread or just a reactivation? A Frontiers review concluded from the existing literature that

our study, consisting more than a total of 113,715 patients, indicates that the RP-SARS-CoV-2 scenario occurs plausibly due to reactivation, reinfection, viral shedding, or testing errors.

So far, there are 240 documented COVID-19 cases of reinfection reported worldwide according to the reinfection tracker. In the case of Ebola there is a known viral persistence in semen while  transmission through milk and cervicovaginal fluid is also possible (similar for COVID-19 although neuronal persistence seems to be more relevant). Maybe we need more immunological studies particular in long COVID if there is a continuous or intermittent antigenic stimulation due to persistence of an antigenic reservoir.

The fourth wave in Germany is caused by the delta variant, reactivation of alpha is certainly not a major factor. So we will only know in the next few years if reactivation is responsible for small regional outbreaks in unvaccinated communities.

Desinformation Experts

another interesting find about “Epistemic Trespassing” by N. Ballantine

Epistemic trespassers are thinkers who have competence or expertise to make good judgments in one field, but move to another field where they lack competence—and pass judgment nevertheless. …  A few examples …Philosophers are especially wary of intruders on their turf. The evolutionary biologist Richard Dawkins has written and lectured on religion. Experts in the philosophy of religion—atheists, agnostics, and theists alike—charge that Dawkins fails to engage with the genuine issues and sets up strawmen as his dialectical opponents. Dawkins appears to overstep his competence as a biologist.

Hygiene conspiracy theorists argue at trumplevel

It is quite interesting to see how the proponents of the hygiene hypothesis are reacting to the Covid-19 pandemic, citing only selected BCG and polio studies and are advising (no disinfectant of course :-) but galectin

The fact that trained immunity can be induced raises the prospect of its exploitation to raise the threshold of resistance to COVID-19 infection … Some studies have already shown that communities that still use Bacillus Calmette–Guérin (BCG) as a vaccine against tuberculosis may have lesser instances of severe COVID-19 infection than those countries that do not use BCG. This notion has been complemented by advocating the use of BCG to vaccinate persons in an attempt to protect them against COVID-19. A recent letter by HIV pioneer Bob Gallo advocated using oral polio vaccine for a similar effect. We consider that administration of galectin molecules, some of which can activate the innate immune system might also represent an approach to reduce the consequences of COVID-19 infection. It is also worth noting that galectin therapy also has the potential to reduce the severity of COVID-19 once infected.

NIH grants EY05093 and AI142862. “Microbes & Infection” has an impact factor 2,3. Published by Institute Pasteur.

The phantom herd immunity to covid-19

When most of a population is immune to an infectious disease either by natural infection or by vaccination, this provides indirect protection — or herd immunity — to those who are not immune to the disease.

A positive antibody response does not necessarily mean that there is immunity but nevertheless it may give a first indication how many individuals may have had contact with a virus. Be aware of several infodemic websites on seroprevalence. Also note that most information is distributed by news agencies, press offices and preprints only bypassing usual standards in science. Unfortunately also most tests have not been properly standardized.


countrydateNrepresentativeantibody prevalence %methodLink
Wuhan, China2Apr201.401no10?journal
Robbio, Italy6Apr202.000?no?13.5?link to Ref 24 by Bendavid not working
Telluride, USA8Apr20986?0.8?newspaper
Santa Clara, USA17Apr203.330no (Facebook)1.5Premier Biotech, Minneapolismedrxiv
Netherlands15Apr207.361no (plasma donors)3.1Wantai Biological PharmacyNIH
Los Angeles, USA20Ap20863yes?4.1?press release
Trieste, Italy22Apr20727no (clinic staff)17.2Wantai SARS-CoV-2 Ab Rapid Testmedrxiv
Brevard, USA24Apr201000no?1.0?newspaper
Miami, USA14Apr201.800yes4.4-7.9?press release
Scotland, GB17Apr201.000no (blood donors)1.0neutralisation assaymedrxiv
Chelsea, USA17Apr20200no (passengers)32?newspaper via Science
New York, USA27Apr207.500??15.0?newspaper
Denmark28Apr209,496no (blood donors)1.7Livzon Diagnostics IgM/IgGmedrxiv
GermanyMay20 (weekly)1.342yes1.0?RKI
Iran1May20551yes22VivaDiag COVID‐19 VivaCheckmedrxiv
Barcelona, Spain2May20578no (healthcare worker)9.3Luminex / Krammermedrxiv
Gangelt, Germany4May20919no (hotspot)14.1Euroimmun?UK Bonn
Padova, Italy1May20133no (health care worker)5.3Chemiluminescencemedrxiv
San Miguel County, USA1May205.455?0.5UB?website
Philadelphia, USA9May20237no (patients)5.9own ELISA / Florian Krammerresearchsquare
Boise, USA7May204.856no (self selected)1.8Abbott SARS-CoV-2 IgGjournal
Kobe, Japan5May201.000no (outpatients)3.3RC-NC002, KURABOmedrxiv
Wake Forest, USA8May20676no (former patients)2.2?newspaper
Lausanne, Schweiz6May20 (weekly)1.335yes3.1, 6.1, 9.7Euroimmunmedrxiv
Brazil10May204.188yes0.05, 0.13Wondfo Biotech medrxiv<7a>
Singapore12May2032.000no (workers in dorms)??newspaper
Berlin, Germany13May205.000 / 7.500no (Charité staff)2.3, 0.3?Ärzteblatt
Spain15May2060.000yes (?)5.0?Reuters
Cambridge, UK15May201.032no (health care worker)3.0own protocolmedrxiv
Hannover, Germany18May20217no (health care worker)1.0Euroimmunmedrxiv
Stockhom, Sweden19May201.104yes?7.3?newspaper
Birmingham, UK22May20554no (health care worker=24.4high-sensitivity ELISA developed in-housemedrxiv


There is  preprint that lists some studies that I could not locate so far.

Prevalences should NOT be compared for methodological reasons.

No idea from where the NYT data originate.