COVID-19 is caused by a new coronavirus, known as SARS-CoV-2. It was first identified in late 2019. It is very infectious and can lead to severe respiratory disease.
Many people who are infected may not have any symptoms or only have mild symptoms. These commonly start with cough, fever, headache and loss of taste or smell.
Some people will feel very tired, have aching muscles, diarrhoea and vomiting, fever and confusion. A small number of people then go on to have severe disease which may require hospitalisation or admission to intensive care.
Overall fewer than 1 in 100 people who are infected will die from COVID-19, but in those over 75 years of age this rises to 1 in 10.
There is no cure for COVID-19 although some newly tested treatments do help to reduce the risk of complications.
In the UK, there are 2 types of COVID-19 vaccine to be used once they are approved. They both require 2 doses to provide the best protection.