Is it true that washing your hands does not prevent infection?
No, hand washing and disinfection are the key to preventing infection.
Hand washing and disinfection are the key to preventing infection. Hands should therefore be washed frequently and thoroughly with soap and water for at least 20 seconds. If soap and water are not available, you can also use an alcohol-based hand sanitizer with at least 60% alcohol. The virus enters the body through the eyes, nose and mouth, so avoid touching them with unwashed hands.
World Health Organization (WHO). Novel Coronavirus (COVID-19) advice for the public: Myth busters (English)
EpiCentro (ISS). Coronavirus and new coronavirus (2019-nCoV) - FAQ
European Center for Disease Prevention and Control (ECDC). Q & A on novel coronavirus (English)