Does soap work better than hand sanitiser?

As the coronavirus outbreak continues, one of the main things people want to know is how to protect themselves. The World Health Organization's advice is to "regularly and thoroughly clean your hands with an alcohol-based hand rub or wash them with soap and water." But which is more effective against the virus? Palli Thordarson is a chemistry professor who posted a widely-shared Twitter thread explaining the difference.

(Photo: Close up of man washing hands in soap and water. Credit: Getty Images)