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Advice on the use of masks in the context of COVID-19 – WHO

Transmission:

According to the current evidence, COVID-19 virus is primarily transmitted between people via respiratory droplets and contact routes. Droplet transmission occurs when a person is in close contact (within 1 metre) with an infected person and exposure to potentially infective respiratory droplets occurs.

N95 vs medical masks:

Meta-analyses in systematic literature reviews have reported that the use of N95 respirators compared with the use of medical masks is not associated with any statistically significant lower risk of the clinical respiratory illness outcomes or laboratory-confirmed influenza or viral infections.

Wearing masks by the general public:

There is limited evidence that wearing a medical mask by healthy individuals in households, in particular those who share a house with a sick person, or among attendees of mass gatherings may be beneficial as a measure preventing transmission.

At present, there is no direct evidence (from studies on COVID-19 and in healthy people in the community) on the effectiveness of universal masking of healthy people in the community to prevent infection with respiratory viruses, including COVID-19.

At the present time, the widespread use of masks by healthy people in the community setting is not yet supported by high quality or direct scientific evidence and there are potential benefits and harms to consider.

https://www.who.int/publications/i/item/advice-on-the-use-of-masks-in-the-community-during-home-care-and-in-healthcare-settings-in-the-context-of-the-novel-coronavirus-(2019-ncov)-outbreak

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Interim Guidance for the Use of Masks to Control Seasonal Influenza Virus Transmission – CDC

Persons who are diagnosed with influenza…should remain at home until the fever is resolved for 24 hours…and the cough is resolving to avoid exposing other members of the public. If such symptomatic persons cannot stay home during the acute phase of their illness, consideration should be given to having them wear a mask in public places when they may have close contact with other persons. 

No recommendation can be made at this time for mask use in the community by asymptomatic persons, including those at high risk for complications, to prevent exposure to influenza viruses.

https://www.cdc.gov/flu/professionals/infectioncontrol/maskguidance.htm

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Robust T cell immunity in convalescent individuals with asymptomatic or mild COVID-19 – bioRxiv

“[R]oughly twice as many people have developed T-cell immunity compared with those who we can detect antibodies in.

SARS-CoV-2-specific memory T cells will likely prove critical for long-term immune protection against COVID-19. We systematically mapped the functional and phenotypic landscape of SARS-CoV-2-specific T cell responses in a large cohort of unexposed individuals as well as exposed family members and individuals with acute or convalescent COVID-19. Acute phase SARS-CoV-2-specific T cells displayed a highly activated cytotoxic phenotype that correlated with various clinical markers of disease severity, whereas convalescent phase SARS-CoV-2-specific T cells were polyfunctional and displayed a stem-like memory phenotype. Importantly, SARS-CoV-2-specific T cells were detectable in antibody-seronegative family members and individuals with a history of asymptomatic or mild COVID-19. Our collective dataset shows that SARS-CoV-2 elicits robust memory T cell responses akin to those observed in the context of successful vaccines, suggesting that natural exposure or infection may prevent recurrent episodes of severe COVID-19 also in seronegative individuals.

https://www.biorxiv.org/content/10.1101/2020.06.29.174888v1.full

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Limited evidence regarding the respiratory protection using non-medical / homemade masks – SAGE

SARS-CoV-2 in the hospital environment and risk of COVID-19 nosocomial transmission

A document produced by SAGE states the following.

Evidence on efficacy of cloth face-coverings (non-medical masks):

There is limited evidence regarding the respiratory protection that non-medical / homemade masks can offer for the wearer, and there are no established quality standards for self-made face masks. One study reported a low filter efficiency (3-33%), and high penetration (up to 97%) of NaCl aerosol particles in homemade masks (42). A trial comparing the use of cloth and medical masks by healthcare workers also showed penetration of microorganisms by 97%, compared with a rate of 44% for medical masks (43).

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/895818/S0485_EMG_SARS-CoV-2_in_the_hospital_environment.pdf

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COVID-19 death rate is higher in European countries with a low flu intensity – Dr. Chris Hope, University of Cambridge

The death rate from COVID-19 (coronavirus) in Europe appears to be linked to low-intensity flu seasons in the past two years as the same people are vulnerable, says a working paper by Dr Chris Hope, Emeritus Reader in Policy Modelling at Cambridge Judge Business School.

https://insight.jbs.cam.ac.uk/2020/flu-and-coronavirus/

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Impact of false positives and negatives, 3 June 2020 – Government Office for Science

The UK operational false positive rate is unknown. There are no published studies on the operational false positive rate of any national COVID-19 testing programme.

An attempt has been made to estimate the likely false-positive rate of national COVID-19 testing programmes by examining data from published external quality assessments (EQAs) for RT-PCR assays for other RNA viruses carried out between 2004-2019 [7]. Results of 43 EQAs were examined, giving a median false positive rate of 2.3% (interquartile range 0.8-4.0%).

Alistair Haimes interpreted these results in this way:

2.3% false positive rate with 0.04% virus prevalence rate (ONS) means that if you test positive you have only a 4/234= 1.7% chance of being infected. We’re flying blind.

if the false positive rate is that high, surely they just know that it is ‘about nothing’; 0.04% must be false precision?

@AlistairHaimes. 3 July 2020

https://www.gov.uk/government/publications/gos-impact-of-false-positives-and-negatives-3-june-2020

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Officially-reported COVID-19 deaths in Ireland likely overestimates – HIQA

HIQA found that the officially-reported COVID-19 deaths likely overestimates the true burden of excess deaths caused by the virus. This could be due to the inclusion within official figures of people who were infected with SARS-CoV-2 (coronavirus) at the time of death whose cause of death may have been predominantly due to other factors.

https://www.hiqa.ie/hiqa-news-updates/covid-19-causes-13-increase-deaths-ireland-between-march-and-june-2020-hiqa

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80.9% of care home residents who tested positive were asymptomatic – Department of Health & Social Care

  • 2.4% of all tests were positive (9,674 out of 397,197)
  • 3.9% of residents tested positive (6,747 out of 172,066)
  • 3.3% of asymptomatic residents tested positive (5,455 out of 163,945)
  • 80.9% of residents who tested positive were asymptomatic (5,455 out of 6,747)
  • 1.2% of asymptomatic staff tested positive (2,567 out of 210,620)

https://www.gov.uk/government/publications/vivaldi-1-coronavirus-covid-19-care-homes-study-report/vivaldi-1-covid-19-care-homes-study-report

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Visualizing the effectiveness of face masks in obstructing respiratory jets – AIP Publishing

The use of face masks in public settings has been widely recommended by public health officials during the current COVID-19 pandemic. The masks help mitigate the risk of cross-infection via respiratory droplets; however, there are no specific guidelines on mask materials and designs that are most effective in minimizing droplet dispersal. While there have been prior studies on the performance of medical-grade masks, there are insufficient data on cloth-based coverings, which are being used by a vast majority of the general public. We use qualitative visualizations of emulated coughs and sneezes to examine how material- and design-choices impact the extent to which droplet-laden respiratory jets are blocked. Loosely folded face masks and bandana-style coverings provide minimal stopping-capability for the smallest aerosolized respiratory droplets. Well-fitted homemade masks with multiple layers of quilting fabric, and off-the-shelf cone style masks, proved to be the most effective in reducing droplet dispersal. These masks were able to curtail the speed and range of the respiratory jets significantly, albeit with some leakage through the mask material and from small gaps along the edges. Importantly, uncovered emulated coughs were able to travel notably farther than the currently recommended 6-ft distancing guideline. We outline the procedure for setting up simple visualization experiments using easily available materials, which may help healthcare professionals, medical researchers, and manufacturers in assessing the effectiveness of face masks and other personal protective equipment qualitatively.

https://aip.scitation.org/doi/pdf/10.1063/5.0016018

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Estimated Inactivation of Coronaviruses by Solar Radiation With Special Reference to COVID-19 – The National Center for Biotechnology Information

“90 percent or more of SARS-CoV-2 virus will be inactivated after being exposed [to summer sun] for 11 to 34 minutes.”

Using a model developed for estimating solar inactivation of viruses of biodefense concerns, we calculated the expected inactivation of SARS-CoV-2 virus, cause of COVID-19 pandemic, by artificial UVC and by solar ultraviolet radiation in several cities of the world during different times of the year. The UV sensitivity estimated here for SARS-CoV-2 is compared with those reported for other ssRNA viruses, including influenza A virus. The results indicate that SARS-CoV-2 aerosolized from infected patients and deposited on surfaces could remain infectious outdoors for considerable time during the winter in many temperate-zone cities, with continued risk for re-aerosolization and human infection. Conversely, the presented data indicate that SARS-CoV-2 should be inactivated relatively fast (faster than influenza A) during summer in many populous cities of the world, indicating that sunlight should have a role in the occurrence, spread rate, and duration of coronavirus pandemics.

https://pubmed.ncbi.nlm.nih.gov/32502327/

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Universality in COVID-19 spread in view of the Gompertz function – medRxiv

COVID-19 appears to follow the Gompertz curve in every outbreak region. This means that government interventions do nothing to stop the virus.

We demonstrate that universal scaling behavior is observed in the current coronavirus (COVID-19) spread in various countries. We analyze the numbers of infected people in selected eleven countries (Japan, USA, Russia, Brazil, China, Italy, Indonesia, Spain,South Korea, UK, and Sweden). By using the double exponential function called the Gompertz function, fG(x)=exp(−e−x), the number of infected people is well described as N(t)=N0 fG(γ(t−t0)), where N0, γ and t0 are the final total number of infected people, the damping rate of the infection probability and the peak time of dN(t)/dt, respectively. The scaled data of infected people in most of the analyzed countries are found to collapse onto a common scaling function fG(x) with x=γ(t−t0) in the range of fG(x) ± 0.05. The recently proposed indicator so-called the K value, the increasing rate of infected people in one week, is also found to show universal behavior. The mechanism for the Gompertz function to appear is discussed from the time dependence of the produced pion numbers in nucleus-nucleus collisions, which is also found to be described by the Gompertz function.

https://www.medrxiv.org/content/10.1101/2020.06.18.20135210v1

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Sentinel surveillance of SARS-CoV-2 in wastewater anticipates the occurrence of COVID-19 cases – medRxiv

SARS-CoV-2 was detected in Barcelona sewage long before the declaration of the first COVID-19 case, indicating that the infection was present in the population before the first imported case was reported. Sentinel surveillance of SARS-CoV-2 in wastewater would enable adoption of immediate measures in the event of future COVID-19 waves.

https://www.medrxiv.org/content/10.1101/2020.06.13.20129627v1

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A Mystery of the Gompertz Function

The Gompertz function describes global dynamics of many natural processes including growth of normal and malignant tissues. On one hand, the Gompertz function defines a fractal. The fractal structure of time-space is a prerequisite condition for the coupling and Gompertzian growth. On the other hand, the Gompertz function is a probability function. Its derivative is a probability density function. Gompertzian dynamics emerges as a result of the co-existence of at least two antagonistic processes with the complex coupling of their probabilities. This dynamics implicates a coupling between time and space through a linear function of their logarithms. The spatial fractal dimension is a function of both scalar time and the temporal fractal dimension. The Gompertz function reflects the equilibrium between regular states with predictable dynamics and chaotic states with unpredictable dynamics; a fact important for cancer chemoprevention. We conclude that the fractal-stochastic dualism is a universal natural law of biological complexity.

https://link.springer.com/chapter/10.1007/3-7643-7412-8_27

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HM Government guidance states evidence for face coverings is weak

Working safely during COVID-19 in offices and contact centres, published 24 June 2020, states:

6. Personal Protective Equipment (PPE) and face coverings
Unless you are in a situation where the risk of COVID-19 transmission is very high, your risk assessment should reflect the fact that the role of PPE in providing additional protection is extremely limited.

6.1 Face coverings
There are some circumstances when wearing a face covering may
be marginally beneficial as a precautionary measure. The evidence
suggests that wearing a face covering does not protect you, but it
may protect others if you are infected but have not developed
symptoms.

It is important to know that the evidence of the benefit of using a face covering to protect others is weak and the effect is likely to be small…

(Emphasis mine)
Screenshot from HM Government publication Working safely during COVID-19 in offices and contact centres, published 24 June 2020.

Advice for offices and contact centres: https://assets.publishing.service.gov.uk/media/5eb97e7686650c278d4496ea/working-safely-during-covid-19-offices-contact-centres-240620.pdf

Advice for restaurants, pubs, bars and takeaway services: https://assets.publishing.service.gov.uk/media/5eb96e8e86650c278b077616/Keeping-workers-and-customers-safe-during-covid-19-restaurants-pubs-bars-takeaways-230620.pdf

Advice for close contact services: https://assets.publishing.service.gov.uk/media/5ef2889986650c12970e9b57/Keeping-workers-and-clients-safe-during-covid-19-close-contact-services-230620.pdf

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Why Face Masks Don’t Work: A Revealing Review – John Hardie, PhD, Oral Health Group (2016)

The primary reason for mandating the wearing of face masks is to protect dental personnel from airborne pathogens. This review has established that face masks are incapable of providing such a level of protection. Unless the Centers for Disease Control and Prevention, national and provincial dental associations and regulatory agencies publically admit this fact, they will be guilty of perpetuating a myth which will be a disservice to the dental profession and its patients. It would be beneficial if, as a consequence of the review, all present infection control recommendations were subjected to the same rigorous testing as any new clinical intervention. Professional associations and governing bodies must ensure the clinical efficacy of quality improvement procedures prior to them being mandated. It is heartening to know that such a trend is gaining a momentum which might reveal the inadequacies of other long held dental infection control assumptions. Surely, the hallmark of a mature profession is one which permits new evidence to trump established beliefs. In 1910, Dr. C. Chapin, a public health pioneer, summarized this idea by stating, “We should not be ashamed to change our methods; rather, we should be ashamed not to do so.” 36 Until this occurs, as this review has revealed, dentists have nothing to fear by unmasking. 

https://www.oralhealthgroup.com/features/face-masks-dont-work-revealing-review/

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What Went Wrong Corona and the World after the Full Stop – Dr. Carlo Caduff, King’s College of London

The failure to take into account the impact of extreme measures that have become the norm inmany places in the Covid-19 pandemic has been stunning. The destruction of lives and livelihoods in the name of survival will haunt us for decades.

Today’s fear is fueled by four main forces:
1. Mathematical disease modelling – a flexible and highly adaptable tool for prediction, mixing calculations with speculations, often based on
codes that are kept secret and assumptions that are difficult to scrutinize from the outside.
2. Neoliberal policies –systematic disinvestments in public health and medical care that have created fragile systems unable to cope with the crisis.
3. Nervous media reporting – an endless stream of information, obsessed with absolute numbers, exploiting the lack of trust in the healthcare infrastructure and magnifying the fear of collapsing systems.
4. Authoritarian longings – a deep desire for sovereign rule, which derives pleasure from destruction and tries to push the world to the edge of collapse so that it can be rebuilt from the scratch.

https://www.kcl.ac.uk/people/carlo-caduff

https://kclpure.kcl.ac.uk/portal/en/publications/what-went-wrong-corona-and-the-world-after-the-full-stop(a4abc6eb-e1b7-4c18-9349-8e36c04826d0).html

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Comment on Flaxman et al. (2020): The illusory effects of non-pharmaceutical interventions on COVID-19 in Europe – Professor Stefan Homburg

Flaxman et al. (Nature, 8 June 2020, https://doi.org/10.1038/s41586-020-2405-7, 2020) infer that non-pharmaceutical interventions conducted by several European countries considerably reduced effective reproduction numbers and saved millions of lives. We show that their method is ill-conceived and that the alleged effects are artefacts. Moreover, we demonstrate that the United Kingdom’s lockdown was both superfluous and ineffective.

https://advance.sagepub.com/articles/Comment_on_Flaxman_et_al_2020_The_illusory_effects_of_non-pharmaceutical_interventions_on_COVID-19_in_Europe/12479987/1

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SARS-CoV-2 T-cell epitopes define heterologous and COVID-19-induced T-cell recognition – Research Square

Up to 81% of of the population can mount a strong response to COVID-19 without ever having been exposed to it before:

Cross-reactive SARS-CoV-2 T-cell epitopes revealed preexisting T-cell responses in 81% of unexposed individuals, and validation of similarity to common cold human coronaviruses provided a functional basis for postulated heterologous immunity

The SARS-CoV-2 pandemic calls for the rapid development of diagnostic, preventive, and therapeutic approaches. CD4+ and CD8+ T cell-mediated immunity is central for control of and protection from viral infections[1-3]. A prerequisite to characterize T-cell immunity, but also for the development of vaccines and immunotherapies, is the identification of the exact viral T-cell epitopes presented on human leukocyte antigens (HLA)[2-8]. This is the first work identifying and characterizing SARS-CoV-2-specific and cross-reactive HLA class I and HLA-DR T-cell epitopes in SARS-CoV-2 convalescents (n = 180) as well as unexposed individuals (n = 185) and confirming their relevance for immunity and COVID-19 disease course. SARS-CoV-2-specific T-cell epitopes enabled detection of post-infectious T-cell immunity, even in seronegative convalescents. Cross-reactive SARS-CoV-2 T-cell epitopes revealed preexisting T-cell responses in 81% of unexposed individuals, and validation of similarity to common cold human coronaviruses provided a functional basis for postulated heterologous immunity[9] in SARS-CoV-2 infection[10,11]. Intensity of T-cell responses and recognition rate of T-cell epitopes was significantly higher in the convalescent donors compared to unexposed individuals, suggesting that not only expansion, but also diversity spread of SARS-CoV-2 T-cell responses occur upon active infection. Whereas anti-SARS-CoV-2 antibody levels were associated with severity of symptoms in our SARS-CoV-2 donors, intensity of T-cell responses did not negatively affect COVID-19 severity. Rather, diversity of SARS-CoV-2 T-cell responses was increased in case of mild symptoms of COVID-19, providing evidence that development of immunity requires recognition of multiple SARS-CoV-2 epitopes. Together, the specific and cross-reactive SARS-CoV-2 T-cell epitopes identified in this work enable the identification of heterologous and post-infectious T-cell immunity and facilitate the development of diagnostic, preventive, and therapeutic measures for COVID-19.

https://www.researchsquare.com/article/rs-35331/v1

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Surgical masks as source of bacterial contamination during operative procedures – Science Direct (2018)

The source of bacterial contamination in SMs was the body surface of the surgeons rather than the OR environment. Moreover, we recommend that surgeons should change the mask after each operation, especially those beyond 2 hours. Double-layered SMs or those with excellent filtration function may also be a better alternative.

https://www.sciencedirect.com/science/article/pii/S2214031X18300809

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UK GDP fell by 10.4% in the three months to April 2020 – Office for National Statistics

In June 2020, The Office for National Statistics released their Gross domestic product (GDP) report for April 2020. They calculated that GDP fell by 10.4% in the three months to April. This was directly caused by the UK government’s policy of lockdown.

https://www.ons.gov.uk/economy/grossdomesticproductgdp/bulletins/gdpmonthlyestimateuk/april2020