WHO Technical Group Advises Public Mask Use To Prevent COVID-19 Transmission – Particularly In ‘Closed’ Environments
(Left-right): Mike Ryan, Dr Tedros Adhanom Ghebreyesus, Maria Van Kerkhove, and Soumya Swaminathan at WHO press briefing Wednesday

The World Health Organization finally appears poised to recommend wider public use of masks as an additional measure to prevent transmission of COVID-19 – after months of hesitation while countries took unilateral action mandating face coverings, particularly for busy shops, transport systems and public settings.

The WHO move, announced at a Wednesday press briefing, follows new recommendations by its Strategic and Technical Advisory Group for Infectious Hazards (STAG-IH),  supporting ” mask use by the general public in the community to decrease the risk of infection.”

In another statement at Wednesday’s briefing, WHO’s Chief Scientist Soumya Swaminathan, said that enrollment would resume in WHO co-sponsored clinical trials of the anti-malarial and lupus drug hydroxychloroquine – after a review of the evidence so far found no significant rise in mortality among people using the treatment.

“The advisory committee of both Solidarity and Recovery have recommended that the trials can continue,” said Swaminathan, referring to the consortiums that are guiding the research with WHO. “We hope that the ongoing trials will continue until we have definite answers. That is what the world needs.” 

WHO suspended the trial last week, in the wake of a Lancet study that seemed to find a higher mortality rates among people taking the drug – although the observational study was later criticized for not adequately taking into account the baseline condition of the patients considered in its analysis of death rates.

Said Swaminathan: “The only way to get definite answers is to do well conducted randomized trials, to see which [treatments] will reduce illness and infection rates in the communities, we should be guided by the science and the evidence.”

STAG Report and Lancet Study Tip the Balance on Mask Recommendations

The STAG advisory group recommendations were released shortly before a WHO-sponsored meta-analysis published by The Lancet, concluded that public use of masks could be an effective infection control measure – although there remains a dearth of robust studies on the topic. 

“Face mask use could result in a large reduction in risk of infection…., with stronger associations with N95 or similar respirators compared with disposable surgical masks or similar (eg, reusable
12–16-layer cotton masks,” the Lancet study concluded.

The STAG advisory group particularly recommended the use of masks in settings where there is “active and widespread community transmission occurring with high attack rates in the population… [for] activities in closed environments without efficient air exchanges, such as commuting on public transportation and over-the-counter consultations in pharmacies.” 

Commuters wear masks to protect against transmission of COVID-19 on a train in Singapore

Public use of facial coverings can also be useful “as part of a transitional package from a ‘confinement’ or ‘stay-at-home’ order to demonstrate solidarity, community empowerment, understanding of the seriousness of the situation,” according to the STAG note.

WHO’s COVID-19 Technical lead Maria Van Kerkove said that updated guidance would be forthcoming in light of the STAG Committee’s recommendations. 

“We are planning to update and release new guidance on use of masks in the coming days,” said Van Kerkhove, in response to a query from Health Policy Watch at a Wednesday press briefing. 

Masks  – As Part of A Continuum of Management

However, Health Emergencies Executive Director Mike Ryan stressed, “We see masks as part of a continuum of risk management, not as an alternative to public health interventions, physical distancing, or surveillance.

“As we move back to work and back to school, everyone is concerned [about] how I can reduce risk. How I can manage the risk to me or my family?

“With regard to the use of masks at the community level, they would mainly be used for the purposes of source control. In other words, [they are recommended] for people who may be infectious, reducing the chances that they will infect someone else,” said Ryan. But mounting evidence of asymptomatic transmission makes it impossible for some people to know if they are indeed infectious or not, and thus the move to wider public mask use may be justified, he acknowledged. 

Wearing masks to protect from COVID-19 in Nigeria Credit: @CRSPHCDA1

The STAG recommendations also underline that the use of masks helps prevent transmission of the virus by asymptomatic or presymptomatic individuals – those who may be infected but not yet showing symptoms. 

“The primary role of masks (of any kind) in the community is to reduce exposure risk for others from infected persons in the pre-symptomatic period,” the STAG-IH group writes. “Infections from such persons are not considered a major driver of the pandemic, but there are concerns that viral loads are highest during the early phase of the disease.”

The WHO move towards wider use of masks has been slow. In the early days of the pandemic, Ryan, Kerkhove and others repeatedly stressed that masks should be limited to health clinics or caring for a sick person at home.  Widespread public use of masks in Asia was described by Ryan as a “cultural” habit – although that habit also clearly originated in the Asian experience with previous pandemics such as the 2003 SARS.

Masked protest in Minneapolis against the death of George Floyd

The WHO message evolved slowly, as  the evidence grew about potential virus transmisison by people with no symptoms, and through simple actions like speaking or singing. The number of countries recommending or requiring facial coverings in public also grew well beyond Asia to Africa, where public health leaders stressed that social distancing is almost impossible, as well as more affluent countries such as Hungary, the Czech Republic, Israel, and some US states.

 

Mask use has become even more significant as countries begin to lift stay-at-home orders. Israel, for instance, which had one of the lowest per capita mortality rates in the height of the pandemic, has seen a rapid rise in cases after lifting its lockdown, and has since strengthened its enforcement of requirements to don masks in schools, stores and other public places. In the US, protestors have been circulating advice via social media to wear masks while attending the massive rallies protesting the death of a Minnesota black man, George Floyd, while in police custody. The mass gatherings have put millions of people into much closer contact with each other in the world’s pandemic epicentre, albeit in outdoors environments. 

 

Image Credits: Jade Lee , Cross River State Primary Health Care, Nigeria , Jenny Salita.