We had it all wrong. The hand sanitizer will not protect you from catching the flu, a new study reveals.

It’s a myth that hand sanitizers kill germs promptly, even those that land you with a cold or flu. While it is true that some germs are removed with a quick squeeze, the flu-causing ones stay on. 

According to a new study published in the journal mSphere, sanitizer products cannot remove the mucus on a person’s fingers. To test this, the researchers patted the participant’s hands with IAV-infected wet mucus.

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“The physical properties of the mucus protect the virus from inactivation,” said a physician and molecular gastroenterologist. “Until the mucus has completely dried, infectious IAV can remain on the hands and fingers, even after suitable antiseptic hand rubbing.”

This mucus can take up to four minutes or more to dry, which means in those four minutes you have a high chance of catching the flu or transferring it to another person. Once the mucus has dried, it can be disinfected with any hand sanitizer.

The US-based Center for Disease Control and Prevention advises people to wash their hands with soap and water instead, to reduce the chances of catching a cold. The researchers who conducted the study also agree, an antiseptic soap can clean up the flu germs within 30 seconds.