Are Masks Scientifically Proven to Help Prevent the Spread of Covid-19?

The battle of scientific studies is on to try to prove that masks worn by healthy populations reduce the spread of Covid-19. Have any of them managed to do it – are masks scientifically proven?

With health authorities weighing in and saying that masks should be worn as well as governments around the world mandating the wearing of masks in public places, shops and schools, there is great pressure on the scientific community to prove their usefulness.

But, are masks scientifically proven?

The short answer is, NO, our assessment is that face masks have not been proven effective in high quality scientific studies to reduce the spread of viruses, including COVID-19, from an infected person to a healthy person, let alone shown value in the masking of healthy people.

But, how can we feel confident making this assertion when there are so many studies taking place and so many ‘experts’ making claims that masks are effective?

First, let’s look at the current official guidance documents and a study from health authorities around the world, including the WHO, European Centre for Disease Prevention and Control, the United States Centers for Disease Control & Prevention and the Irish Department of Health in regards to their assessments of scientific evidence for mask effectiveness.

We will conclude with an excerpt from Prof. Carl Heneghan, Director of the Centre for Evidence-based Medicine, University of Oxford, UK who gave testimony to the DÁIL ÉIREANN Special Committee on Covid-19 Response, Thursday, 13 August 2020.

Health Authorities Agree that Scientific Studies Have Not Proven Masks to be Effective

Below you will see excerpts and links to the most recent guidance documents on each of these health authority’s website regarding masks. There is a great deal of information given on each site of how to best source or make, wear and dispose of masks but they all have one thing in common…

They all fail to state that masks have been scientifically proven to be effective.

They either actually assert that masks have not been proven effective, warn of evidence gaps, are unable to cite reputable and conclusive studies and therefore use wording such as ‘may help’ and even warn against possible side-effects.

World Health Organization (WHO) ¹WHO.int Advice on the use of masks in the context of COVID-19 (pdf downloadable from here: 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)

‘At present, there is no direct evidence (from studies on COVID19 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.’

World Health Organization (WHO): Advice on the use of masks in the context of COVID-19, page 6. PDF available from: 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

European Centre for Disease Prevention and Control (ECDC)²ECDC Using face masks in the community - Reducing COVID-19 transmission from potentially asymptomatic or pre-symptomatic people through the use of face masks, Executive Summary Available from: https://www.ecdc.europa.eu/en/publications-data/using-face-masks-community-reducing-covid-19-transmission

‘It is not known how much the use of masks in the community can contribute to a decrease in transmission in addition to the other countermeasures.’

‘Recommendations on the use of face masks in the community should carefully take into account evidence gaps, the supply situation, and potential negative side effects.’

[In reference to the recommendation of using cloth facemasks] ’This is based on limited indirect evidence supporting the use of non-medical face masks as a means of source control.’

ECDC Using face masks in the community - Reducing COVID-19 transmission from potentially asymptomatic or pre-symptomatic people through the use of face masks, Executive Summary Available from: https://www.ecdc.europa.eu/en/publications-data/using-face-masks-community-reducing-covid-19-transmission

United States Centers for Disease Control & Prevention (CDC)³CDC Considerations for Wearing Masks Available from: https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/cloth-face-cover-guidance.html

‘Masks may help prevent people who have COVID-19 from spreading the virus to others.’

CDC Considerations for Wearing Masks Available from: https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/cloth-face-cover-guidance.html

This website cites 19 different scientific studies to support their recommendation that masks should be worn but still use the word ‘may.’ The conclusion could be drawn that they remain unable to make a definitive statement regarding the scientific evidence proving the benefits of mask use.

United States Centers for Disease Control & Prevention⁴Xiao J, Shiu E, Gao H, Wong JY, Fong MW, Ryu S, et al. Nonpharmaceutical Measures for Pandemic Influenza in Nonhealthcare Settings—Personal Protective and Environmental Measures. Emerg Infect Dis. 2020;26(5):967-975. Available from: https://wwwnc.cdc.gov/eid/article/26/5/19-0994_article

‘Our systematic review found no significant effect of face masks on transmission of laboratory-confirmed influenza … In this review, we did not find evidence to support a protective effect of personal protective measures or environmental measures in reducing influenza transmission.’

Xiao J, Shiu E, Gao H, Wong JY, Fong MW, Ryu S, et al. Nonpharmaceutical Measures for Pandemic Influenza in Nonhealthcare Settings—Personal Protective and Environmental Measures. Emerg Infect Dis. 2020;26(5):967-975. Available from: https://wwwnc.cdc.gov/eid/article/26/5/19-0994_article

Irish Department of Health⁵When to wear face coverings and how to make them, Gov.ie Available from: https://www.gov.ie/en/publication/aac74c-guidance-on-safe-use-of-face-coverings/

‘Wearing of cloth face coverings may help prevent people who do not know they have COVID-19 (Coronavirus) from spreading it to others.’

When to wear face coverings and how to make them, Gov.ie Available from: https://www.gov.ie/en/publication/aac74c-guidance-on-safe-use-of-face-coverings/

The above link provides no citations of scientific studies providing evidence for mask effectiveness.

DÁIL ÉIREANN Special Committee on Covid-19 Response, Thursday, 13 August 2020⁶Prof. Carl Heneghan, Director of the Centre for Evidence-based Medicine, University of Oxford, UK who gave testimony to the DÁIL ÉIREANN Special Committee on Covid-19 Response, Thursday, 13 August 2020. Available here: https://www.oireachtas.ie/en/debates/debate/special_committee_on_covid-19_response/2020-08-13/4/

'...evidence comparing cloth masks to surgical masks or the N95s shows clearly that cloth masks are worse and may actually increase the risk of infection. Therefore, that is why they are not recommended in hospitals or in health professional settings.

What happens in these situations of uncertainty is that the opinion divides. Someone thinks mask are a good idea while someone else does not think they are and that people should not wear them. That is why we end up with people proposing them more and more. They say people should put them on in schools, pubs and shops. However, there is no clear evidence. They use observational data to inform their decision. If one looks at what has happened in the UK, for instance, it put masks in on 24 July. They were supposed to reduce the risk of infection by 40% over the next two weeks. In fact, infections detected have gone up. In effect, people are not looking at the evidence.

When Norway looked at this, it said that at low circulation, the public health consequences were so minimal that it was not clear they worked and, even if they did work, it reckoned about 200,000 people would have to wear a mask fully for a week to prevent one infection.

That is how one has to think about the uncertainty. If one is going to put a policy in place, that is fine. What one cannot do, however, is say it is evidence-based because when people talk about the evidence, they have again cherry-picked low-quality, observational evidence to suit the argument. However, they have not picked further observational evidence. For instance, if one puts masks in, what is one expecting to happen to the case definitions and the reductions in the next two to four weeks to show it was a worthwhile policy to enact?'

Prof. Carl Heneghan, Director of the Centre for Evidence-based Medicine, University of Oxford, UK statement to DÁIL ÉIREANN Special Committee on Covid-19 Response, Thursday, 13 August 2020. Available from: https://www.oireachtas.ie/en/debates/debate/special_committee_on_covid-19_response/2020-08-13/4/

Are Masks Scientifically Proven?

If the very organisations that are making recommendations and even mandating the wearing of masks are unable to clearly assert and cite reputable evidence-based studies which scientifically prove the wearing of masks prevents the spread of COVID-19, we can be fairly confident that this scientific evidence has not been provided.

One might ask themselves the question… why are they promoting and mandating masks ahead of actual proof?

Furthermore, there is a large research gap in studies carried out around the safety of wearing masks, particularly for long periods of time and in children. With thousands of members of the Irish workforce as well as secondary level students whose school is unable to provide 2m distancing being mandated to wear masks/ face coverings, one might also ask the question of how these measures are being justified without any evidence of safety?

What do you think, are masks scientifically proven?

If some people wish to wear a mask because it makes them feel good, that should be their right, but we cannot stand behind mandating a practise that is not scientifically proven to be effective or safe.