Hand sanitizer is the first line of defense against sniffles and sneezes –– but infectious disease experts say people can put too much trust in its capabilities.
“Most of your common viruses like influenza, COVID virus, they’re wimps. They’re easy to kill with hand sanitizer,” said Chuck Gerba, a microbiologist at the University of Arizona. He noted that these viruses have a fatty layer that soap and standard disinfectants can dissolve.
However, although alcohol-based hand sanitizer can inactivate other viruses like COVID, “norovirus doesn’t have a lipid layer and it’s much tougher to kill,” Gerba said.
That’s why alcohol-based hand sanitizers are not effective against norovirus, or as Thomas Russo, an infectious disease expert and distinguished professor of medicine at the University at Buffalo, dubbed it: the “winter vomiting disease,” named after its hallmark symptoms.
Since norovirus can live on surfaces for two weeks, hand hygiene is critical –– but you need to know which cleaning method is best for reducing your transmission risk, experts say.
Norovirus cases surge in the winter months, Russo said. He cited how viral survival favors cold, dry weather, and indoor crowds and holiday travel increases person-to-person contact.
Moreover, there is no vaccine immunity from norovirus. Russo noted there are vaccines for common winter viruses like influenza, respiratory syncytial virus (RSV) and COVID, but there is no shot for norovirus at this time, so people are more vulnerable to catching it. Although rare, 900 U.S. adults who were mostly ages 65 and older even die from norovirus every year.
“Norovirus is not inactivated by the alcohol-based sanitizers,” Russo said, so his recommendation for preventing the illness is vigorous hand washing with soap for at least 20 seconds, which will inactivate the virus and remove the particles from your skin.
Alcohol-based hand sanitizers do kill flu, measles and COVID viruses, but Russo also notes that the main method of transmission of these viruses is through the air. Measles is back in the U.S., and “measles is really good with aerosols and can remain lingering in the air for up to two hours after someone that’s infected has left that closed space,” he said as an example.
It’s one more reason you should not assume one kind of hand hygiene is enough to protect your health this winter. Too many people think “as long as I have good hand hygiene, it’s all good, and I’m not going to get infected,” Russo said. To avoid this fate, vaccinate yourself against respiratory viruses, and consider using both hand-washing and hand sanitizer to keep viruses from spreading.
“You can use hand sanitizers in addition to hand washing, but hand sanitizer is not a substitute for handwashing, which is best” against norovirus, according to the Centers for Disease Control.
Take it from the professionals, who recommended using both when you suspect you may get sick from a winter virus. Gerba said in shopping malls and on cruise ships, he will often wash his hands with soap and water, and also use Advanced Purell hand sanitizer, which contains the CDC-recommended level of at least 60% alcohol, to cover all his bases.
Gerba cited a 2024 study he co-authored, which found that using an automatic-dispensing hand sanitizer after using a public restroom significantly reduced the chances of getting norovirus and COVID.
“In addition to washing your hands...you should really use a hand sanitizer on the way out,” Gerba said, noting that people’s hands are germiest after being in public spaces.
This way, you can enjoy the season for cozy evenings indoors –– and avoid the sniffles and viruses that come with it.