A pandemic is a global outbreak of disease caused by a new strain of coronavirus. The new strain was identified in December 2019 in China and spread quickly to other countries around the world, prompting WHO to declare a public health emergency of international concern on 30 January 2020 and to characterize the outbreak as a pandemic on 11 March 2020. You can help slow the spread of infection during a pandemic by following guidance from your local council, such as staying 1.5m away from others and avoiding crowds or gatherings. Stay tuned to the radio and TV, or check trusted government websites for updates. You can also get vaccinated to protect yourself against the virus and help prevent the outbreak from becoming more severe.
There have been 22 documented pandemics in human history: two by smallpox (the Antonine Plague and the American Plague), three by plague (Black Death, the Great Plague of London and the Third Plague), seven by cholera, six by influenza (two Russian Flu, Spanish Influenza, Asian Influenza and Swine Flu), one by rabies and a number by bacterial infections including AIDS.
Some pandemics have been zoonotic, meaning they originated in wild animals and then spread to humans. For example, sARS, MERS, and the new coronavirus are all believed to have zoonotic origins, and AIDS likely came from bats, palm civets, and other wild primates as indigenous people hunted and consumed these animals in parts of Africa where the disease became endemic. In terms of economic impact, simulations from the 2014 Ebola epidemic in West Africa suggest that a low-severity pandemic could reduce GDP by around 1 percent, while a high-severity event might reduce it by 3-4 percent. This includes direct losses due to deaths, as well as indirect costs such as reduced demand through avoidance of travel, restaurants and other places, and prophylactic absenteeism from work.