- Experts say the safety protocols used to reduce risk during the COVID-19 pandemic can help protect you from colds and flu this fall and winter.
- They explain that colds, flu, and COVID-19 are all spread by droplet transmission.
- They say that’s why mask wearing and physical distancing work against these illnesses.
All data and statistics are based on publicly available data at the time of publication. Some information may be out of date.
The same precautions taken to avoid COVID-19 will also help guard against colds and the flu.
As health authorities brace for a cold and flu season that will coincide with COVID-19, experts are encouraging the public to continue practicing good hand hygiene, physical distancing, and mask wearing to not only prevent COVID-19 but also colds and influenza.
“Cold and flu, COVID-19 — they’re all respiratory viruses. There are nuances between them, but basically they are all transmitted in the same way,” Dr. William Schaffner, an infectious disease expert at Vanderbilt University in Tennessee, told Healthline.
The transmission of respiratory illnesses is divided into two categories: droplet transmission and airborne transmission.
“The idea is that respiratory spread via droplet transmission is from larger, heavier droplets, heavier particle size, and they don’t travel very long,” Dr. Dean Blumberg, chief of pediatric infectious diseases at the University of California Davis, told Healthline. “They don’t stay suspended in the air for very long because gravity takes over and they fall to the ground, and that’s why we have all those recommendations relating to social distancing 6 feet or farther away from people.”
“Respiratory spread from airborne transmission refers to viruses and other infections that are suspended in smaller particles in the air,” Blumberg said. “These are smaller and lighter particles so they can remain floating around in the air and carried around by air currents for minutes to even hours.”
When it comes to respiratory droplets, size matters.
“Normal respiratory droplets that carry things like the common cold, SARS-COV-2, or influenza are large and typically cause infection by direct contact or through a contaminated surface where it has landed,” Dr. Jaime Friedman, a pediatrician in San Diego, told Healthline.
The common cold and influenza are both believed to be transmitted through larger droplets.
And although there is still much to learn about COVID-19, it is believed to be spread in the same way.
“With COVID-19, probably at least two thirds of transmission is from the respiratory route via droplets,” Blumberg said.
Experts say the droplet transmission is why mask wearing is so important.
“Within that zone, that breathing zone, of 3 to 6 feet, that’s where the virus is transmitted most efficiently and, of course, since people without symptoms can be shedding the virus, quite as abundantly as people with symptoms, that’s the whole rationale for wearing masks,” Blumberg said.
Masks act as a barrier that stop larger droplets being transmitted to others once exhaled, minimizing the risk of spread.
“They protect against the outgoing. They’re really excellent at that. They’re OK at protecting against the incoming, what it is that you inhale. But they really are very effective at protecting against the outgoing,” he said. “Think about surgeons. The reason they wear facial masks are so that the germs in their mouths and nose don’t drop into the surgical wound. So if everyone wears masks they are protecting themselves, but even more so they’re protecting everyone else around them and if we all did that then the ability of this virus to be transmitted, would not drop to zero, but it would be very substantially curtailed.”
Experts are hopeful mask wearing and other COVID-19 prevention measures will also help reduce the number of influenza cases this winter.
“The same considerations apply between influenza and COVID-19. Wearing a mask and social distancing are the two most important things… to prevent influenza and if people follow that for COVID-19 we may get a break and see less influenza this year,” Blumberg said.
Experts say an effective mask is one that has two or more layers, such as surgical masks that are multi-layered.
The way a mask is worn also matters.
“The best mask… is the one that is worn correctly over the nose and mouth and for the entire duration that person is in a public space,” Friedman said.
Masks should also fit snugly around the cheeks and down under the chin.
Schaffner says mask wearing should become more commonplace in the United States to guard not only against COVID-19, but many other infections.
“I think it’s past time that we begin to adopt those practices here in the U.S. and in the Western world generally,” he said. “Of course, it helps to keep socially distant. Lots of good hand hygiene also helps. In addition, there’s one other thing that we can do against flu which is of course to get vaccinated.”
The Southern Hemisphere is just emerging from their flu season, and Blumberg said the patterns seen there are indicative of the widespread benefits of COVID-19 measures such as mask wearing.
“In Taiwan, there was a 75 percent decrease in influenza… related to the masking and social distancing guidelines. You can see decreases in many different infections by following these guidelines for masking and social distancing,” he said.
As well as getting the flu shot, experts are urging the public to maintain infection prevention measures as cold and flu season begins.
“Continue social distancing when in public, continue to wear a mask, continue to wash your hands and sanitize frequently touched surfaces, continue to avoid large indoor gatherings,” Friedman said.
Schaffner says if people embrace mask wearing, the benefits to public health and the healthcare system would be significant.
“We would diminish very substantially if we did this consistently,” he said. “That would spare a lot of us from annoying illnesses, the relatively small minority would be spared very serious disease and of course the burden on the healthcare system would be substantially less and we’d save literally millions of dollars.”
But Schaffner says that as well as mask wearing, hand hygiene and physical distancing all have a role to play in avoiding cold, flu, and COVID-19.
“Each of these interventions that we use has utility, they all contribute to it,” he said. “None of them is perfect, but if we use several of them simultaneously then the barrier gets stronger and each compensates for the holes in the others.”