- There is no scientific evidence that masks are effective in reducing the risk of SARS-CoV-2 transmission.
- Sweeping mask recommendations will not reduce SARS-CoV-2 transmission, as evidenced by the widespread practice of wearing such masks in Hubei province, China.
- Cloth masks will be ineffective at preventing SARS-CoV-2 transmission, whether worn as source control or as PPE.
- Surgical masks likely have some utility as source control from a symptomatic patient in a healthcare setting to stop the spread of large cough particles and limit the lateral dispersion of cough particles.
- Surgical masks may also have very limited utility as source control or PPE in households.
- Authors do not know whether respirators are an effective intervention as source control for the public.
- A non-fit-tested respirator may not offer any better protection than a surgical mask.
- Respirators work as PPE only when they are the right size and have been fit-tested to demonstrate they achieve an adequate protection factor.
- There is no evidence to support use of cloth masks by the public or healthcare workers to control the emission of particles from the wearer.
- Wearing surgical masks in households appears to have very little impact on transmission of respiratory disease.
- There is no evidence that surgical masks worn by healthcare workers are effective at limiting the emission of small particles or in preventing contamination of wounds during surgery.
- There is moderate evidence that surgical masks worn by patients in healthcare settings can lower the emission of large particles generated during coughing and limited evidence that small particle emission may also be reduced.
- Data from laboratory studies indicate masks offer very low filter collection efficiency for the smaller particles.
- The authors were unable to locate any well-performed studies of cloth mask leakage when worn on the face—either inward or outward leakage.
- Many references to coverings employ very crude, non-standardized methods or are not relevant to cloth face coverings because they evaluate respirators or surgical masks.
- The National Academies of Sciences Rapid Expert Consultation on the Effectiveness of Fabric Masks for the COVID-19 Pandemic: “The evidence from…laboratory filtration studies suggests that such fabric masks may reduce the transmission of larger respiratory droplets. There is little evidence regarding the transmission of small aerosolized particulates of the size potentially exhaled by asymptomatic or presymptomatic individuals with COVID-19.”
- Authors concerned that many people do not understand the very limited degree of protection a cloth mask or face covering likely offers as source control for people located nearby.
- Cloth masks and face coverings likely do not offer the same degree of protection as physical distancing, isolation, or limiting personal contact time.
- Transmission is not simply a function of short random interactions between individuals, but rather a function of particle concentration in the air and the time exposed to that concentration.
- A cloth mask or face covering does very little to prevent the emission or inhalation of small particles.
Center for Infectious Disease Research and Policy
Browse the articles related to this topic below.
Join our community on Guilded.
At today’s hearing, several committee members pressed the WHO and vaccine company officials on two main issues. They expressed deep suspicions that vaccine industry experts on WHO advisory groups improperly influenced the WHO’s assessment of the pandemic in order to financially benefit pharmaceutical companies. Council members also questioned the WHO official, Dr Keiji Fukuda, special advisor on pandemic influenza to the WHO director-general, about confusion surrounding consideration of severity in its definition of a pandemic, which was revised at about the time the novel H1N1 virus was identified.
Some government public health officials and influenza experts have strongly rejected Wodarg’s claims, defending vaccine stockpiling as a prudent public health response and calling the charges “preposterous.”
In his opening statement, Wodarg said he was skeptical about the threat of the H5N1 virus and the contracts that countries had in place with vaccine makers in the event of a pandemic. “WHO had the trigger,” he said, alluding to the pandemic plans of some countries that activate the contracts when the WHO declares the highest alert level. He speculated that vaccine makers are making a financial windfall from what he claims are more expensive patented and adjuvanted vaccines. He also argued that the billions that governments have spent on pandemic vaccines could be better spent on other health issues.
He charged that the change in pandemic definition “made it possible to turn a run-of-the-mill flu into a pandemic and translate into millions for vaccine for no good reason.”
Wodarg also claimed that adjuvanted vaccines used in Europe were not adequately tested, especially in children, and expressed doubts about the safety of cell-based pandemic vaccines.