Evidence shows that masks can suppress the transmission of COVID-19 by preventing respiratory droplets from infecting others.
Since the start of the COVID-19 pandemic, there has been much debate around the benefits of face masks.
A post from an Instagram account, which is known for spreading medical misinformation, cites results from a "Stanford study" to claim that face masks are ineffective in blocking COVID-19. The post also provides a URL to the study.
Initially, health institutions such as the World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC) recommended face coverings only for health care workers. However, as time passed and science evolved, new data proved that masks are an effective way to suppress the transmission of COVID-19.
WHO encourages the use of masks as a part of a "comprehensive strategy of measures to suppress transmission and save lives." The CDC explains that face coverings can help reduce the emission of droplets from asymptomatic or presymptomatic people, who may feel well but could still be infectious.
The study in question has no connection to Stanford University. According to USA Today, Stanford has denied any affiliation to the author. In addition, Julie Greicius, spokeswoman of the Stanford School of Medicine, stated that the university supported face masks in the current pandemic. Greicius added that the study was not a Stanford study and that the university "requested a correction."
The misinformed study was first published on Facebook in April 2021. Several fact checking organizations, including Factcheck.org, have debunked the claims made in the study.
CORRECTION: The initial claim – "face masks don't stop the transmission of COVID-19" – was marked false. We realize that this implied mask-wearing completely stops the spread of COVID-19. This is not the case, as mask-wearing only reduces the spread of COVID-19.
The COVID-19 pandemic has given rise to a lot of potentially dangerous misinformation. For reliable advice on COVID-19, including symptoms, prevention, and available treatment, please refer to the World Health Organization or your national healthcare authority.