How does it work?

“The first line of defence is the innate immune system,” says Dr Macciochi. “If the cells that line these areas [previously mentioned] detect a pattern of germs that’s common to viruses or parasites, they activate a non-specific inflammation to try and make a hostile environment to stop the germ from taking hold.” Think heat, pain, redness and swelling. If this isn’t enough to clear the infection after a few days, your body shifts gear to something called the adaptive immune response. “This response is made up of white blood cells and is unique to that infection. The cells clone themselves to produce an ‘army’ of these specific cells before leaving a small population of ‘memory cells’ that stay in your body to produce a fast response if you were to encounter the same virus again.” For some viruses, like chickenpox, these memory cells protect you for life. Currently, estimations for COVID-19 are that immunity could last as little as three months. But this could change as we learn more.