Studies corner

[Branster]

There are so many snippets of information regarding small tests, case studies and even research from all over the world, some interesting, some surprising, some hopeful. Too many and too small or sometimes obscure to make the main news

If you’d like to share you are welcome to join the thread.

I’ll make a start with these findings from Canada about a potential inhibitor drug

www.sciencedaily.com/releases/2020/04/200402144526.htm

Wish I'd known about this thread before. Interesting! Thank you.

Dietary micronutrients in the wake of COVID-19: an appraisal of evidence with a focus on high-risk groups and preventative healthcare

No surprise that poor nutrition and low levels of some micronutrient worsen prospects if infected.
Vit D is the most prominant deficiency atm

nutrition.bmj.com/content/early/2020/06/17/bmjnph-2020-000100

Prevalence of serum IgG antibodies against SARS-CoV-2 among clinic staff

https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0235417&type=printable

We were interested to examine the SARS-CoV-2-IgG anti- body status among clinic staff of a large neurological center in Northern Germany.

Blood samples and questionnaires (demographic data, medical history) were collected pseudony-mously.

In total, 406 out of 525 (77.3%) of our employees participated in the study.

The infection rate among the staff was as high as 2.7%.
Including drop-outs (missing question- naire but test result available), the infection rate was even higher (2.9%).

Only 36% of the positively tested employees did suffer from flu-like symptoms in 2020.

None of the nurses - having closest and longest contact to patients - were found to be positive.

Declining IFR or death rate in English hospitals

www.cebm.net/covid-19/declining-death-rate-from-covid-19-in-hospitals-in-england/

We've seen declining death rate in German hospitals too

• probably due to the lower average age more than improved treatment

Useful table showing over the weeks how death rate rose and then fell, as age did

It wasn't health service capacity either

• German hospitals & ICU had high spare capacity even at peak

and patients were admitted immediately on having breathing difficulties or low blood O2

Royal Society preprint: Vitamin D and COVID-19

royalsociety.org/-/media/policy/projects/set-c/set-c-vitamin-d-and-covid-19.pdf

"Deficiency in Vitamin D is more commonly found in older individuals, those of black or Asian ethnic origin, and people who are obese.

These are also factors known to increase risk of more severe COVID-19.

However, correlations are not the same as causality."

The way people are claiming the fatality rate is dropping is really odd. It's probably true but that's not the way to asses it, you do studies of all those admitted on a particular day.

Interesting that the government have said publicly that vitamin D is important for pregnant women and are claiming they have said all along that you should supplement if indoors. It's true that it is on the NHS website but I dont think its been in government briefing. I wonder if anyone in government ever reminded care homes or even gps about it.

If our government devoted as much time to managing this epidemic as they did to looking at how they can deflect blame we'd have had fewer deaths.

CDC: High COVID-19 Attack Rate Among Attendees at Events at a Church — Arkansas, March 2020

https://www.cdc.gov/mmwr/volumes/69/wr/mm6920e2.htm

Among 92 attendees at a rural Arkansas church during March 6–11,

35 (38%) developed laboratory-confirmed COVID-19,
and three persons died.
....
Highest attack rates were in persons aged 19–64 years (59%)
and ≥65 years (50%).

An additional 26 cases linked to the church occurred in the community,
including one death.
....
What are the implications for public health practice?

Faith-based organizations should work with local health officials to determine how to implement the U.S. Government guidelines for modifying activities during the COVID-19 pandemic
to prevent transmission of the virus to their members and their communities.

Immunity may be higher than antibody studies suggest ttps://news.ki.se/immunity-to-covid-19-is-probably-higher-than-tests-have-shown?_ga=2.20276920.1468983411.1593603573-673256794.1593603573

another interesting drug - but very early stages news.ki.se/rheumatoid-arthritis-drug-shows-promise-against-covid-19-study-finds?_ga=2.20276920.1468983411.1593603573-673256794.1593603573

endothelial damage believed to be behind the clotting problems - and a possible treatment that may help www.newswise.com/coronavirus/covid-19-blood-clotting-cause-identified-in-study-led-by-yale-cancer-center-researchers/?article_id=733915

Belgian care homes had a lot of asymptomatic cases www.thelancet.com/journals/laninf/article/PIIS1473-3099(20)30560-0/fulltext

but had all the symptomatic ones already been taken to hospital?

opinion piece on why fomite risk is exaggerated www.thelancet.com/journals/laninf/article/PIIS1473-3099(20)30561-2/fulltext

lessons from autopsies www.medrxiv.org/content/10.1101/2020.07.02.20145003v1

Immunity %

Benjamin Meyer@BenjaminMeyer85

1. Since there was a huge discussion about T-cell mediated immunity following the Lancet comment on seroprevalence by @EckerleIsabella and me,

I'd like to share my thoughts on this in the following thread:

1. There are 2 different points that are discussed at the moment:

First, there are some studies, i.e.

Targets of T Cell Responses to SARS-CoV-2 Coronavirus in Humans with COVID-19 Disease and Unexposed Individuals
https://tinyurl.com/y8zzf8tw

that show a cross-reactive T-cell response in sample taken before the pandemic,
due to previous infection with common cold coronaviruses.

1. While I do trust these studies, as the authors pointed out themselves, it is in my opinion

quite unclear what this cross-reactive T-cell response means in terms of protection.

We know that despite having this specific T-cell response against common cold CoVs, we do

1. get regularly infected by them (every couple of years).

So it obviously does not prevent infection in the upper respiratory tract and also not transmission of the common cold CoVs,
otherwise they should have died out long time ago.

Therefore, I think it is save to assume that

1. if the specific T-cell response cannot prevent infection and transmission, the cross-reactive response against SARS-CoV-2 cannot prevent it either.

However, the cross-reactive T-cell response might or might not play a role in the protection of patients against severe disease

1. Yet, as of today we do not know whether this is true or not and we need to investigate it further.

Second, it has been described that people exposed to SARS-CoV-2 only mount a T-cell response but do not produce any antibodies.

From this, some people like to conclude that

1. seroprevalence rates are vastly underestimating the true exposure rate and that we are closer to herd immunity that we think.

While I do believe that these patients exist, I don't think that they comprise a large proportion that dramatically changes the exposure rate.

1. In a recent paper from us,

"Validation of a commercially available SARS-CoV-2 serological immunoassay
To validate the diagnostic accuracy of a Euroimmun SARS-CoV-2 IgG and IgA immunoassay for COVID-19."
https://tinyurl.com/yb9388be

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

"Clinical and immunological assessment of asymptomatic SARS-CoV-2 infections"
https://tinyurl.com/y9f39twv

mounted neutralizing antibodies.

1. These findings indicate, that we do not miss many exposed individuals in the current seroprevalence studies.

In conclusion, I think we should not fall back into wishful thinking that an underestimated T-cell immunity will resolve this pandemic.

10. In the absence of more data on the potential effect of cross-reactive T-cells on the severity of COVID-19, it is dangerous to lower our guard and loose certain measures such as wearing masks and social distancing.

PHE: Evaluation of sensitivity and specificity of four commercially available SARS-CoV-2 antibody immunoassays

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachmentdata/file/898437/Evaluationoffsensitivityanddspecificityoff4commerciallyyavailableSARS-CoV-22antibodyimmunoassays.pdf

Sensitivity was evaluated on 536 positive samples from unique adult individuals with laboratory-confirmed SARS-CoV-2 infection at ≥20 days post-symptom onset;

specificity was evaluated on 994 pre-pandemic (2015-2018) specimens < hence negative ! > from unique, healthy adult individuals.

All 4 commercial tests met specificity criteria, but only Siemens met sensitivity as well

large Spanish study, one third of positive cases asymptomatic www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(20)31483-5.pdf

COVID-19 Actuaries Response Group: Is COVID-19 Seasonal?

Analyses COVID papers on climate, temp & humidity

https://henrytapper.com/2020/07/09/is-covid-19-seasonal/

The study found that the most affected cities were located within a narrow geographic band (broadly 30°N to 50°N)
and that they had similar mean temperatures (between 5°C and 11°C).

This study suggested that, based on climatic conditions in March and April,
community spread was likely to affect areas north of the existing areas at risk.
In particular, Eastern and Central Europe, the UK, the Northeastern and Midwestern United States were areas mentioned as being at risk during March and April

In addition, recent clusters of reported cases of COVID-19 in meat packing facilities in Germany and the United States are also indicative that
temperature and humidity are likely to be factors in the spread of COVID-19
– the environment in these facilities is cold and humid; with people working very close together.
.....
The physiology behind relative humidity and infection is not fully understood or proven,
but it is hypothesised that we may be less able to clear our airways of trapped pathogens at lower relative humidity,
whilst there may be more aerosolised virus at higher humidity, and hence more exposure opportunity.
......
The human immune system also appears to experience seasonality, with higher vulnerability to infection in winter months.
It has been suggested that this is either due to vitamin D or seasonality of melatonin production.
.....
For Northern hemisphere countries, seasonality is likely to mean that
infections will remain at a relatively low level over the summer months,
despite the easing of social distancing and other non- pharmaceutical interventions (NPIs).

However, if it does not prove possible to keep the number of infections to a very low level,
we would expect to see a second wave of infection in the winter months

Levels of infection in frontline health workers in London www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)31484-7/fulltext?dgcid=raven_jbs_etoc_email

CMMID: Reconstructing the global dynamics of unreported COVID-19 cases and infections

https://cmmid.github.io/topics/covid19/Under-Reporting.html

Conclusions:
We found substantial under-ascertainment of symptomatic cases, particularly at the peak of the first wave of the SARS-CoV-2 pandemic, in many countries.

Reported case counts will therefore likely underestimate the rate of outbreak growth initially
and underestimate the decline in the later stages of an epidemic.

Although there was considerable under-reporting in many locations, our estimates were consistent with emerging serological data,

suggesting that the proportion of each country’s population infected with SARS-CoV-2 worldwide is generally low.

ECDC’s latest risk assessment as of 2 July

https://www.ecdc.europa.eu/sites/default/files/documents/RRA-Resurgence-of-reported-cases-of-COVID-19-in-the-EU-EEA.pdf

They assess that 29 of 31 countries (EU/EEA and UK) passed their peak of infection between 10 and 91 days before 30 June,
but that Bulgaria and Sweden had only recently passed their peak, and had infection rates within 10% of the highest observed rates.

They note the number of outbreaks in certain higher risk settings, in particular meat processing centres

They list measures needed to keep new outbreaks under control

How Esoul got on top of its nightclub outbreak - but not before it had spread to 5 and 6 level contacts wwwnc.cdc.gov/eid/article/26/10/20-2573_article

King’s College London team found steep drops in patients’ antibody levels three months after infection

One of several studies confirming this
No evidence either that significant additional numbers of people - especially elderly people, who are at much higher risk - can fight COVID with T cells

Looks like any vaccination program might need to be annual, as for flu

• but that would be a manageable logistics challenge

https://www.theguardian.com/world/2020/jul/12/immunity-to-covid-19-could-be-lost-in-months-uk-study-suggests

People who have recovered from Covid-19 may lose their immunity to the disease within months,
according to research suggesting the virus could reinfect people year after year, like common colds.

If immunity is only going to last a few months even annual vaccination may not protect you, which is a really depressing though. It does reinforce the need to find treatments as well as looking at vaccination.

Face Masks Considerably Reduce COVID-19 Cases in Germany

40% reduction in infections

50% reduction in infections for those aged 60+

• and that group had about 90% of the deaths here

http://ftp.iza.org/dp13319.pdf