While some experts argue that masks are of utmost importance, researchers warn that they might only be helpful in containing the Coronavirus spread by up to 60 per cent

A lot of efforts to slow the spread of the Coronavirus comes down to a seemingly simple concept — Wearing a mask. But the issue has proven a thorny one. Health authorities have changed their guidance on who should wear masks and when. This has led to some confusion and even suspicion.

But since the Coronavirus first appeared, authorities have gained a better understanding of how it spreads and how masks can help stop that spread. Here’s a look at how, what we know about, masks has changed, and how government officials are increasingly getting behind the idea of mandating the use of masks.

What the experts say?

The US Centers for Disease Control and Prevention has long advised people to wear masks because they help prevent people who are infected — whether they know it or not — from spreading the Coronavirus. But last week, the CDC added a new reason — masks can also protect wearers who are not infected, though to a lesser degree.

The agency referred to a study led by Japanese researchers that found masks block about 60 per cent of the amount of virus that comes out of an infected person. When an uninfected person wearing a mask is near an infected person who isn’t wearing one, the amount of virus the uninfected person inhaled fell by up to 50 per cent. But when both people are wearing masks, that produced the best result. The decline in virus particles reaching the second person was close to 70 per cent.

So, if everyone wears a mask when social distancing is not feasible, the infection rate will be cut, experts say.

A study done in Denmark, published in Annals of Internal Medicine, seemed to question whether and to what extent masks protect the wearer. The study had a number of flaws, however, as the researchers acknowledged. For example, study participants who were supposed to wear masks sometimes didn’t. And the work was done at a time when not much Coronavirus was spreading in Denmark — there wasn’t a lot of data to conclude from.

Either way, experts say masks, while helpful, are not perfect. Keeping a distance, being in well-ventilated areas, and washing hands are also important ways to reduce risk.

How is this different from what has been said?

Surgeon General, US, Jerome Adams had tweeted on February 29, “Seriously people — Stop buying masks! They are not effective in preventing general public from catching #Coronavirus.”

But today, Adams has a different message pinned to the top of his Twitter account. “When we can’t stay six feet away from others, please, I’m begging you, wear a face covering,” Adams says in the videotaped July 2 tweet. And in July, the CDC stressed that cloth face coverings are a critical tool in the fight against COVID-19, particularly when everyone wears them.

Similarly, the WHO early on had recommended against mask-wearing for the general public, saying they might lead to a false sense of security and that people who didn’t know how to use them properly could infect themselves. The World Health Organisation changed its advice in June. It now suggests that people should wear masks when they are outdoors at a crowded area or when they can’t be socially distant.

Even though not everywhere around the world, there is a mask rule, especially in some states of the US, but some countries, including Asian, have mandated mask use, from requiring them everywhere in public to using them on public transportation and in stores.