Influenza is the most deadly airborne virus in the United States, annually impacting about 5 to 20 percent of Americans and hospitalizing some 200,000 of them, according to the U.S. Centers for Disease Control and Prevention. But following a few simple steps can provide the arsenal needed to keep you and your family healthy through flu season.

To set the record straight, Dr. Bryan Stone, an internal medicine specialist and nephrologist, and Wally Kowalski, a mechanical engineer who specializes in designing air filtration systems that can fight flu particles, are sounding off on how the virus works and what you can do to prevent from getting it.

Mediaplanet: Why is flu season from October to April—and why are we most susceptible to getting it this time of year?

Kowalski: People tend to stay indoors during the winter and airborne illnesses thrive in indoor spaces.

MP: What does “airborne” mean?

Kowalski: An airborne virus can be transmitted through droplets that stay suspended in the air in an indoor space. Small virus particles are emitted anytime anyone who’s infected with the flu coughs, breathes, or sneezes, and those droplets rapidly evaporate down to particulates. Large virus particles precipitate from the air and settle on surfaces to become fomites—which, if they’re touched, can be transmitted to the hand then to the mouth, the nose or the eyes. Someone who is sick emits 11 virus particles per minute.

MP: What about “animal” strains of the flu—like swine flu and avian flu, which we’ve previously seen?

"The problem with the flu is you’re dealing with something you can’t see or smell. Someone could walk in the room and you don’t know if they’re breathing out these particles."

Dr. Stone: Viruses can be transmitted from people but also from animals. The flu is constantly evolving, so that makes it hard to build up an immune defense to it—and that goes for animals, too.

MP: What are the best ways to prevent the flu?

Kowalski: There are three prongs: vaccination, hygiene and air cleaning technologies.

What are air cleaning technologies, and how can they fight bacterial infections like the flu?

Kowalski: The flu is vulnerable to ultraviolet light and air cleaning systems, which are available online or retail stores. They can eliminate up to 99 percent of flu particles from the air, which can be helpful if you live with someone fighting the flu. Always opt for devices that have been tested in independent laboratories and can filter 99 percent or more of bacterial particles.

MP:  Just how effective is the flu shot?

Dr. Stone: It’s safe for almost everybody, and it’s especially recommended for the elderly and young children. Scientists have built the vaccine based on mathematical models—and the shot is effective only if the people around you have gotten it too. That’s the only downside of the vaccine, but that’s also why schools and offices often offer free flu shots.  

MP: Why is hand washing or staying away from infected people isn’t enough?

Dr. Stone: The problem with the flu is you’re dealing with something you can’t see or smell. Someone could walk in the room and you don’t know if they’re breathing out these particles. You can’t clean it with household chemicals. You can clean a surface of your desk or a table but that only fixes it for a moment. Bleach can’t fix that. Air filter systems are key—it’s about cleaning the air.

MP: What’s your best tip for preventing the flu?

Kowalski: Avoiding people who have it! With flu transmission, proximity is key: Data show if you’re five feet away from a person with the flu, you’re 100 percent, or two times, as likely to catch the flu than if you’re standing 20 feet away.