Medical masks may be flying off the shelves of some local pharmacies because of the latest coronavirus. Here’s why you should think twice before buying one.Surgical masks can reduce the spread of airborne diseases from people who are already infected to others. They do not, however, protect wearers from contracting the disease and there’s little research to show that they work outside of hospitals or clinics.Eyewitness News has reported that these masks are selling out at some local pharmacies such as Dis-Chem, although there are no cases of the new coronavirus — dubbed COVID-19 — in South Africa yet.TIMELINE | How China's new coronavirus spreadThere is a global shortage of medical masks as demand for the products soars because of the outbreak. Not only are suppliers struggling to keep up with demand from countries such as China with large numbers of cases, but the World Health Organisation (WHO) also says unnecessary purchasing and hoarding of masks by the general public is adding to the problem. The strain on international supplies of the products may mean that healthcare workers, who are most at risk of contracting the virus and need special masks, will have to go without. “The demand [for masks] is up to 100 times higher than normal and prices are up to 20 times higher,” said WHO Director-General Tedros Adhanom Ghebreyesus speaking earlier this month at a press conference.Less than two months after the first case was reported, China — which has seen the vast majority of cases — was already running in short supply of the masks. The national health department has experienced delays in orders for the type of respirator masks used exclusively by healthcare workers. These masks are the most effective at preventing airborne infections such as COVID19 and TB but only if people receive specialised training on how to use them — and if they are the correct size.According to the WHO, the only people who should be using any mask are those who have symptoms of the COVID-19 infection, or those taking care of someone who does. “People with no respiratory symptoms, such as cough, do not need to wear a medical mask,” the global health body explains on its website.So do you need a mask? The answer is no. Other things that have, for instance, been circulating on social media, that will not protect from COVID-19, according to the WHO:Eating garlicCovering your body with alcohol, chlorine or sesame oilRinsing your nose with salineAvoiding goods from ChinaSmokingThe most important thing you can do to protect yourself from any infection is to wash your hands frequently. Regularly washing your hands with soap and water — or an alcohol-based sanitizer — will help kill viruses on your skin and reduce your chances of getting sick.People should also avoid touching their eyes, nose and mouth, as viruses can be transmitted through your hands into your body. ALSO READ | South Africa could face TB mask shortage because of coronavirus outbreakYou should also cover your mouth and nose when you cough either with your elbow or a tissue to prevent spreading any illness. All used tissues should be immediately thrown away. If you develop a fever, cough and difficulty breathing then, the WHO says, it’s time to see a doctor. This story was produced by the Bhekisisa Centre for Health Journalism. Subscribe to the newsletter.