WHO thought this was a good idea...

Yesterday, December 1, 2020, the World Health Organization rolled out its interim guidance document "Mask use in the context of COVID-19". [1] According to the WHO, the document is an update of the guidance that was published on June 5, 2020, and is based on "...new scientific evidence relevant to the use of masks for reducing the spread of SARS-CoV-2…"

 Regarding the use of masks, the WHO immediately notes:

 However, the use of a mask alone, even when correctly used (…), is insufficient to provide an adequate level of protection for an uninfected individual or prevent onward transmission from an infected individual (source control). 

Translation: There is no evidence that the use of a mask will afford any protection to the wearer, and there is no evidence that wearing a mask will prevent the wearer from spreading the virus to others.

 The WHO then reinforces this position with:

 At present there is only limited and inconsistent scientific evidence to support the effectiveness of masking of healthy people in the community to prevent infection with respiratory viruses, including SARS-CoV-2.

That is certainly the opinion found in the preponderance of scientific literature, and the WHO stresses the need for evidence based decision making. Which is odd since in the document, the WHO then makes the recommendation for mask wearing based on "indirect evidence" that masks may be beneficial. Since when does responsible science throw out direct reproducible evidence and replace that objective direct evidence with "indirect evidence" that better suits our desired political position? 

In particular, regarding community masking, (i.e. all other mask wearing outside of Health Care Facilities), the WHO references two papers of particular interest: the Bundgaard study[2] (which they mis-reference) and which I have already addressed, and the Jefferson review.[3]

The Jefferson review is an update of earlier Cochrane Reviews that were published as early as 2007. The review is particularly noteworthy since the evidence summarized in their review does not include results from studies from the current COVID-19 pandemic. Now, although I can't speak for the authors, there is probably a good reason for their exclusion and those reasons may be found in the, now famous, retractions of various studies from the New England Journal of Medicine, the Proceedings of the National Academy of Science, The Lancet and other journals who had to retract studies that should never have been published in the first place (I have addressed some of those issues elsewhere).

Regarding the selection process used in the Jefferson review, the authors note that in previous reviews they included observational studies, however for this updated review, there was a sufficient number of randomized controlled trials (RCTs) and cluster-RCTs of trials investigating physical interventions to meet their study goal. The authors identified 44 new RCTs and cluster-RCTs for a total of 67 randomized trials.

Thus, the review is a meta-analysis, and it would be reasonable to presume the review, however diligent, has all the problems seen with meta-analyses in general, and the authors are forthright and honest with that cautionary comment.  

One aspect of the review was to compare the use of medical/surgical masks to wearing no mask at all; of which there were nine trials (eight of which were cluster-RCTs); two trials with healthcare workers and seven of community masking. 

The results of those studies indicated there was low certainty evidence from nine trials (consisting of 3,507 participants) that wearing a mask may make little or no difference to the outcome of viral influenza-like illness (ILI) such as COVID-19 compared to not wearing a mask. There is moderate certainty evidence that wearing a mask probably makes little or no difference to the outcome of laboratory-confirmed ILI compared to not wearing a mask (6 trials with 3,005 participants).

Another aspect was to look at actual respirators (N95/P2) compared to medical/surgical masks wherein there were four trials in healthcare settings and one in an household setting. The results indicated there was no clear evidence to suggest that the respirators had any clear benefit over the use of masks, on the outcomes of clinical respiratory illness (that is, very low-certainty evidence; 3 trials; 7,779 participants) and also for ILI (also low-certainty evidence; for 5 trials, 8,407 participants). The authors opined:

The use of a N95/P2 respirator compared to a medical/surgical mask probably makes little or no difference for the objective and more precise outcome of laboratory-confirmed influenza infection (RR 1.10, 95% CI 0.90 to 1.34; moderate-certainty evidence; 5 trials; 8,407 participants). Restricting the pooling to healthcare workers made no difference to the overall findings.

 So, overall, the findings are consistent with the vast overwhelming body of science that indicates there is no scientific evidence to support the latest masking craze, and (as noted in the WHO document), there may be some harm and there is a probability that masks may actually increase infection rates and/or there may be other "harms."

I should take a moment and note that in the past, I have been critical of claims that masking reduces arterial oxygen and increases volatile acid and I addressed that elsewhere. However, recently, a reader pointed me to two articles that seem to suggest that is a possibility.[4],[5] I admit, I'm skeptical, but, I'll keep an open mind, and invite any readers to add on to the list or studies you've conducted (published or otherwise).

Similarly, in the same vein, the WHO document addresses face shields, and strikes a blow to business in areas where mask mandates require the use of face masks but people claim exemption due to medical problems. In such situations, businesses try to force the customer to wear a degrading and stupid "face-shield" that is every bit as useless as a face mask. For those businesses, I draw attention to WHO's comments:

At present, face shields are considered to provide a level of eye protection only and should not be considered as an equivalent to masks with respect to respiratory droplet protection and/or source control.

 Still, it begs the question: If the WHO knows masks are useless, but recommends wearing them anyway, then why doesn't the WHO similarly recommend wearing face-shields? Perhaps a discussion better had over a beer.

WHO Practical Applications

 WHO provides what it believes are practical applications for community mask wearing. However, in reality, if one followed the "practical guidelines," a person in public would be changing out their mask every few minutes and would probably have to cycle through a couple hundred new/fresh masks per day. As such, the WHO practical applications are not very "practical" after all and especially since there is no known benefit to wearing the mask in the first place and as of today, December 2, 2020, there is no scientific evidence or medical justification for community mask wearing. 

CONCLUSIONS

The WHO document was definitely written by committee and it shows. One can pick through it and find just about any contradicting position one wants to find and it will legitimately be there. For example, two paragraphs that are found next to each other are:

However, the use of a mask alone, even when correctly used (see below), is insufficient to provide an adequate level of protection for an uninfected individual or prevent onward transmission from an infected individual (source control).

 And:

 Masks can be used for protection of healthy persons (worn to protect oneself when in contact with an infected individual) or for source control (worn by an infected individual to prevent onward transmission) or both.

It really seems the document was prepared to be seen to be doing something, without actually doing anything at all. The document is full of "perhaps"s, "could"s, "may"s, "possibly"s and other terms to ensure as much ambiguity as possible.

Although only 22 pages long, the uselessness starts early in the document, and it won't take the reader long to figure out that they probably have something more productive they could (should, perhaps, maybe, possibly) be doing.

 Caoimhín P Connell, Forensic Industrial Hygienist

December 2, 2020

Other COVID-19 discussions by CP Connell:

How to Peddle Backward - What happened to the 2020 Flu Epidemic? A summary of the US Crude Mortality Rate's refusal to cooperate with the popular narrative.

WHO thought this was a good idea... (Comments regarding the December 1, 2020, "Mask use in the context of COVID-19".)

  The Failing Mask Cure Aid a review of Bundgaard H, Bundgaard JS, Raaschou-Pedersen DET, et al, "Effectiveness of Adding a Mask Recommendation to Other Public Health Measures to Prevent SARS-CoV-2 Infection in Danish Mask Wearers, A Randomized Controlled Trial" (Ann. Int. Med. Nov 18, 2020, https://doi dot org/10.7326/M20-6817).

 Don't be a Maskhole, Karen A review of Zeng N, Li Z, Ng S, Chen D, Zhou H, Epidemiology reveals mask wearing by the public is crucial for COVID-19 control. (Medicine in Microecology, https://doi.org/10.1016/j.medmic.2020.100015):  

 Masks, and the new Doctor Schnabel von Rom: Review of Stadnytskyi V, Bax CE, Bax A, Anfinru P, The airborne lifetime of small speech droplets and their potential importance in SARS-CoV-2 transmission (Approved by PNAS May 2020: https://www.pnas.org/cgi/doi/10.1073/pnas.2006874117)

Pathological Science - Zhang et al and the PNAS: Zhang R, Annie Y Zhang L, Wang Y, Molinae M: Identifying airborne transmission as the dominant route for the spread of COVID-19 (fast-tracked through the PNAS on June 11, 2020)

Defacing Mask Science - Rossettie S, Perry C, Pourghaed M, Zumwalt M, "Effectiveness of manufactured surgical masks, respirators, and home-made masks in prevention of respiratory infection due to airborne microorganisms" The Southwest Respiratory and Critical Care Chronicles 2020;8(34):11–26

Masks - Don't look behind the curtain: Review of Vivek Kumar, Sravankumar Nallamothu, Sourabh Shrivastava, Harshrajsinh Jadeja, Pravin Nakod, Prem Andrade, Pankaj Doshi, Guruswamy Kumaraswamy "On the utility of cloth facemasks for controlling ejecta during respiratory events "

 Size matters! A Brief Description of filtering mechanisms and size.

Materials v. Masks: A review of Konda A, Prakash A, Moss GA, Schmoldt M, Grant GD, Guha S "Aerosol Filtration Efficiency of Common Fabrics Used in Respiratory Cloth Masks" (American Chemical Society, April 2020)

"Junk Science: In Favor of Community Face Masks - a return to Lysenkoism" A review of: Jeremy Howard, Austin Huang, Zhiyuan Li, Zeynep Tufekci, Vladimir Zdimal, Helene-Mari van der Westhuizen, Arne von Delft, Amy Price, Lex Fridman, Lei-Han Tang, Viola Tang, Gregory L. Watson, Christina E. Bax, Reshama Shaikh, Frederik Questier, Danny Hernandez, Larry F. Chu, Christina M. Ramirez, Anne W. Rimoin Face Masks Against COVID-19: An Evidence Review NOT PEER-REVIEWED | Posted: 13 May 2020

Wishful Science - A review of Anna Davies, BSc, Katy-Anne Thompson, BSc, Karthika Giri, BSc, George Kafatos, MSc, Jimmy Walker, PhD, and Allan Bennett, MSc Testing the Efficacy of Homemade Masks: Would They Protect in an Influenza Pandemic? (Disaster Med Public Health Preparedness. 2013;7:413-418)

If Manikins Could Fly… A Review of Eikenberry SE, Mancuso M, Iboi E, Phan T, Eikenberry K, Kuang Y, Kostelich E, Gumel AB "To mask or not to mask: Modeling the potential for face mask use by the general public to curtail the COVID-19 pandemic" (Infectious Disease Modelling 5 (2020) pp. 293-308)

Review of Cheng VC, Wong S, Chuang V, So S, et al "The role of community-wide wearing of face mask for control of coronavirus disease 2019 (COVID-19) epidemic due to SARS-CoV-2" (Journal of Infection April 30, 2020;16:13)

Gassed Masks! Reactivation of viruses and deoxygenation during mask wearing.

Masking the Truth - A discussion of aerosols and droplets

We R0 New York City - A discussion of the basic reproduction number.

The epidemic of ignorance: Lessons from "Flattening the Curve" April 14, 2020

Think Tanks! The Dangers of Group-Think April 13, 2020

References

[1] World Health Organization 2020. Some rights reserved. This work is available under the CC BY-NC-SA 3.0 IGO licence. WHO reference number: WHO/2019-nCoV/IPC_Masks/2020.5

[2] Bundgaard H, Bundgaard JS, Raaschou-Pedersen DET, et al, "Effectiveness of Adding a Mask Recommendation to Other Public Health Measures to Prevent SARS-CoV-2 Infection in Danish Mask Wearers, A Randomized Controlled Trial" (Ann. Int. Med. Nov 18, 2020, https://doi.org/10.7326/M20-6817)

[3] Jefferson T, Del Mar CB, Dooley L, Ferroni E, Al-Ansary LA, Bawazeer GA, van Driel ML, Jones MA, Thorning S, Beller EM, Clark J, Hoffmann TC, Glasziou PP, Conly JM. "Physical interventions to interrupt or reduce the spread of respiratory viruses." Cochrane Database of Systematic Reviews 2020, Issue 11. Art. No.: CD006207. DOI: 10.1002/14651858.CD006207.pub5.

[4] Kao T, Huang K, Huang Y, et al "The physiological impact of wearing an N95 maskduring hemodialysis as a precaution against SARS in patients with end-stage renal disease" J Formos Med Assoc. 103(8):624-8, 2004 Aug.

[5] Beder A, Büyükko?ak U, Sabuncuo?lu H, Keskil ZA, Keskil S, "Preliminary report on surgical mask induceddeoxygenation during major surgery" Neurocirugia (Astur);19(2):121-6, 2008 April doi: 10.1016/s1130-1473(08)70235-5.