Update 09/04/2020: The World Health Organization (WHO) has recently reviewed its position on face masks in light of new evidence, updating its advice guidelines on April 6, but has maintained its original position that it's not necessary for the general public to wear them. Although masks could help limit the spread of COVID-19, the WHO concluded they are insufficient on their own and cannot guarantee protection. 

There’s been a lot of flip-flopping when it comes to health authorities’ stances on face masks, leading to confusion about their effectiveness in preventing the spread of COVID-19. So, here’s the latest on face masks, their effectiveness, and why there’s so much controversy around the issue.

Government U-Turns

One of the biggest U-turns on face masks came from the US on April 3, when the Centers for Disease Control and Prevention (C DC) issued new guidelines advising people to wear cloth face masks if they leave their house. This advice came after weeks of insisting the public should only wear the mask if they were sick or were directly caring for infected people. 

To further add to the confusion, President Donald Trump said the guideline to wear face masks was "voluntary,” adding "You do not have to do it. I don't think I'm going to be doing it." 

The World Health Organization (WHO) on the other hand argues that face masks should only be worn by carers and not by the general public. However, after initially following this recommendation, numerous governments in Europe have now told their citizens to wear face masks in public. 

What Does The Science Say? 

Scientists are still undecided on whether SARS-CoV-2, the coronavirus responsible for COVID-19, is airborne and can be spread via aerosol (tiny floating droplets of liquid that are coughed or sneezed out). While it could take years for scientists to reach a cast-iron consensus, there is increasing evidence that airborne droplets are an important mode of transmission.

If this is the case, then a physical barrier over the nose and mouth could provide some protection. A recent study by the University of Maryland, published in the journal Nature Medicine, found that face masks may limit the spread of some seasonable respiratory diseases, including coronaviruses. Although the research didn’t assess whether the mask protects the wearer from infections, it did suggest they may limit how much an infected person can spread infectious respiratory diseases through coughs and sneezes. 

Some Chinese experts have even suggested that the US and Europe are struggling to cope with the outbreak because they are culturally averse to wearing face masks in public, as opposed to many parts of East Asia where they are the norm. "The big mistake in the US and Europe is that people aren't wearing masks," George Gao, the head of the China Center for Disease Control, told the journal Science.

However, not all public health experts are convinced. One of the main points of argument is that viruses are tiny and would be able to penetrate most face masks. 

“What confuses people about mask use is whether it provides absolute protection; does it stop all virus? The answer to that, for most masks, is no. But if you ask if it stops some virus, the answer is yes,” said Professor Ian Jones, Professor of Virology at the University of Reading, UK.

Scarce Supplies

Some experts say any protection is better than nothing, but others say unnecessarily wearing face masks is wasteful – which is perhaps one of the most important points in the debate.

Many countries across the world have reported difficulty in obtaining enough personal protective equipment (PPE), especially face masks, for their frontline healthcare staff. These are the people who need the scarce supplies the most. After all, the risk to the public walking down the street is much lower compared to healthcare workers coming into close contact with a huge number of infected patients daily.

“We should also remember that face masks are not an infinite resource and should be reserved for when they are most effective. It would not be good if we were not able to provide masks to healthcare workers because the public had consumed supplies,” said Dr Ben Killingley, Infectious Disease Physician at the Royal Free Hospital in London. 

In light of this, the CDC is now advising people covering their nose and mouth with any cloth mask, even if that's a scarf or bandana.

Follow Your National Health Authority's Advice

In sum, it’s no surprise if you've felt a bit confused about the issue. If you’re still in doubt, you should check your national health authority's website for advice. They will – hopefully – be able to give you the latest and most relevant advice based on your own country’s situation.