A group of experts is urging the World Health Organization (WHO) to update its guidelines, recommending that healthcare workers use respirator-level masks instead of surgical face masks for protection against flu-like illnesses, including Covid-19.
In a letter to WHO chief Dr. Tedros Adhanom Ghebreyesus, the experts stated that surgical masks, which are widely used globally, offer "inadequate protection against airborne pathogens" and that there is "no rational justification" for their continued prioritization. They advocate for respirators, such as those meeting FFP2/3 (UK) or N95 (US) standards, to be standard practice whenever doctors and nurses are in direct contact with patients.
During the peak of the Covid-19 pandemic, approximately 129 billion disposable face masks were used monthly worldwide. As evidence emerged, many countries began recommending respirators as more effective than surgical masks.
The authors contend that implementing this change would result in fewer infections among patients and health professionals, thereby reducing sickness, absence, and burnout within the health workforce.
Professor Adam Finkel from the University of Michigan School of Public Health, a letter organizer, explained that surgical masks were initially designed to prevent contamination from healthcare workers, not to block airborne pathogens. He described them as "obsolete" compared to modern respirators.
The letter, authored by seven clinicians and scientists and endorsed by nearly 50 senior clinicians and researchers and over 2,000 public members, originated from discussions at an online conference. It suggests that governments could establish "off-ramps" where respirator use might not be necessary, based on factors such as community infection rates and indoor air quality.
Although the proposed guidance would apply specifically to healthcare settings, where infection risk is higher, it could generate controversy given the politicization of face masks during the Covid-19 pandemic. The signatories believe that an update to WHO's infection prevention and control guidelines to recommend respirators could have a substantial global impact, even without mandatory enforcement. They also propose leveraging the WHO's procurement infrastructure to improve access to respirators, particularly in lower-income countries.
Finkel noted that while surgical masks block about 40% of Covid-sized particles, respirators block approximately 95%. Critics of the group's stance cite a lack of randomized controlled trials (RCTs) proving the effectiveness of physical measures against respiratory viruses. The authors argue that such trials are impractical and that laboratory physical tests demonstrating respirator efficacy are sufficient.
The letter also calls on the WHO to explicitly state that Covid-19 spreads via "airborne respiratory particles," addressing previous criticism that the organization was slow to adopt this description.
Professor Trisha Greenhalgh of the University of Oxford, a signatory whose research is cited in the letter, emphasized that respirators effectively filter airborne germs by sealing tightly against the face, unlike medical masks which fit loosely and allow significant leakage.
A WHO spokesperson confirmed the letter requires "careful review" and stated that the organization is currently reviewing its Infection Prevention and Control guidelines for acute respiratory infections based on the latest scientific evidence.