Video shares falsehoods about face masks and asymptomatic spread of Covid-19

12 July 2021
What was claimed

Asymptomatic carriers of Covid do not spread disease.

Our verdict

This isn’t true. As the pandemic has gone on, it has become clear that asymptomatic transmission can occur.

What was claimed

There is no reduction in viral transmission with the use of face masks.

Our verdict

Face masks can help to reduce transmission of SARS-Cov-2, and are recommended in many scenarios by the WHO and the UK government.

What was claimed

Face masks can cause low oxygen levels in the body.

Our verdict

The WHO has explicitly said that surgical masks do not cause low oxygen levels.

A video which has been shared on social media shows a woman, who claims to be an attorney, speaking at the Orange County Board of Supervisor meeting on 2 June 2020.

The video includes many outdated or untrue claims about the Covid-19 pandemic. 

Asymptomatic carriers of SARS-CoV-2 can transmit infection 

The video claims that “asymptomatic carriers of Covid do not spread disease.”

At the beginning of the Covid-19 pandemic, there was uncertainty about how much transmission of SARS-CoV-2 would occur from people who had asymptomatic infections. 

Over the course of 2020 and 2021, however, the role of asymptomatic transmission has become clearer and we now know that people with asymptomatic infection can transmit Covid-19. 

We have written more about this previously. 

Face masks can help to reduce the spread of Covid-19 

In the video, it is claimed that face masks “do not work to stop the virus”.

The role of face masks in preventing the transmission of SARS-CoV-2 was uncertain at the beginning of the pandemic. 

The evidence and guidance around mask use has evolved since to give support to the use of masks in some situations. We have written more about the intricacies of this previously. 

The UK government now states that mask wearing can “reduce the spread of coronavirus droplets in certain circumstances, helping to protect others”. This is echoed by the World Health Organisation (WHO) advice that, in addition to other measures, “masks are a key measure to suppress transmission and save lives.”

Depending on the type of mask used, their main effect may be in protecting others, while some particular types of masks provide additional protection for the wearer.

As England moves into the next stage of easing coronavirus restrictions on 19 July, legal obligations to wear face masks are set to be removed (although people will still be expected to wear them in crowded indoor areas). The legal requirement to wear masks is still currently in place in Wales, Scotland and Northern Ireland.

Standard surgical face masks do not cause hypoxia 

The video also claims that face masks “cut the oxygen ‘hypoxically’ low.”

Hypoxia is a medical term for low or insufficient oxygen levels in the body. The claim that  face masks can cause hypoxia is not true, and has been fact checked many times before

The WHO have said that, while facemasks can be uncomfortable, surgical face masks do not lead to oxygen deficiency. 

Paul Hunter, Professor in Medicine at the University of East Anglia, conducted a review of the evidence on mask-wearing in April 2020 and previously told Full Fact that ordinary face masks and coverings do not cause low oxygen levels. 

There is some evidence that some specific types of respirator masks used in medical settings (N95/FFP2 masks) can alter gas exchange.

This article is part of our work fact checking potentially false pictures, videos and stories on Facebook. You can read more about this—and find out how to report Facebook content—here. For the purposes of that scheme, we’ve rated this claim as false because asymptomatic transmission of Covid-19 can occur, standard face masks do not cause hypoxia, and there is some evidence to suggest that face masks can reduce viral transmission.

Full Fact fights bad information

Bad information ruins lives. It promotes hate, damages people’s health, and hurts democracy. You deserve better.