TedEd: Which is better: Soap or hand sanitizer?

A TedEd by Alex Rosenthal and Pall Thordarson

The strain of coronavirus that causes COVID-19 has an outer membrane made of lipids. They are pin shaped molecules that are attracted to water, forming a natural circular shell in water-rich environments. This is also called the hydrophobic effect. This shape helps the virus break into the cells in our bodies and infect them. However, it has many many weak points where something like soap could break in. Soap molecules, called amphiphiles, look similar to the lipids, and they fight for space in the virus's membrane. This irregularity is just enough to break the virus apart, and the amphiphiles form bubbles around the lipids and the virus's RNA to keep it from infecting cells. Now to hand sanitizer. If you dry the virus then add the alcohol in sanitizer, it makes the hydrophobic effect of the virus membrane disappear, taking the whole thing down. For COVID-19, hand washing is better, as it can get all the dirt on your hands and virus cells that may be hiding in them. This isn't true for all viruses, however. The common cold is caused by rhinoviruses, which don't have as many weak points for soap to attack. This means that sanitizer is more effective in attacking it. In the end, the best method is to listen to the health advisors and follow their advice.