There are general principles you can follow to help prevent the spread of respiratory viruses, including:
wash your hands often - with soap and water for at least 20 seconds. Use an alcohol-based hand sanitiser that contains at least 60% alcohol if soap and water are not available. This is particularly important after taking public transport
avoid touching your eyes, nose, and mouth with unwashed hands
avoid close contact with people who are sick
if you feel unwell, stay at home, do not attend work or school
cover your cough or sneeze with a tissue, then throw the tissue in a bin. See Catch it, Bin it, Kill it
clean and disinfect frequently touched objects and surfaces in the home and work environment
if you are worried about your symptoms, please call NHS 111. Do not go directly to your GP or other healthcare environment
see further information and the Public Health England Blog
There is currently no vaccine to prevent COVID-19 acute respiratory disease. The best way to prevent infection is to avoid being exposed to the virus.