Each year, communities around the world suffer from a dangerous and potentially deadly infectious disease: influenza. The story is a familiar one: the virus jumps from one person to the next via a cough, a sneeze or a contaminated surface, linking people and places via long and intertwined chains of transmission.

What most people do not realize is that these person-to-person chains also represent a huge potential for interrupting transmission.

What most people do not realize is that these person-to-person chains also represent a huge potential for interrupting transmission. Influenza virus uses these chains to find new people to infect, and vaccines can block these pathways between people. Every vaccinated person protects both themselves and others, by stopping the virus from spreading. Vaccination reduces your risk of spreading influenza virus and increases your contributions to protecting your entire community.

Our best chance at keeping everyone healthy this winter season is to strengthen our community immunity — or herd immunity — by ensuring that as many people as possible are vaccinated. But each year, more than half of Americans miss out on the opportunity to contribute to community immunity and protect themselves, their family and friends because they skip the flu vaccine.

Some Americans skip the flu vaccine because they think the flu is just an average head cold. It’s not. It causes severe illness and death, even in otherwise healthy people. Two children have already died from the flu this year, and the flu season is only just beginning — more people will die and tens of thousands will wind up in the hospital before the season ends next spring. Even a milder case of influenza can put an otherwise healthy adult in bed with a fever, chills and body aches for at least a week, and the illness’s effects can ripple outward for far longer. On average, every time you get the flu, you’re likely to infect 1-2 other people, who will each pass it on to 1-2 more people, and so on.

Some Americans skip the flu vaccine because they aren’t aware of the good they can do by getting it. The U.S. Centers for Disease Control and Prevention estimates that people who got the flu vaccine in 2016-2017 helped prevent 5.3 million cases of flu. Preventing millions of people from suffering and thousands from dying is a major success worth celebrating, but we could be doing so much more if everyone got vaccinated. The fact is, everyone gets the flu from someone else, meaning skipping the flu vaccine and becoming a link in the chains of transmission has consequences that extend to family, friends, co-workers and even people who pass us by on the bus and in the supermarket.

Some Americans skip the flu vaccine because they think it doesn’t work well. It’s true that the vaccine cannot prevent all cases of flu, but that alone shouldn’t be a reason to opt out of the benefits it provides. While there is no way to perfectly prevent the flu (yet), getting vaccinated is the most effective option available.

In the five minutes it takes to get a flu vaccine, you acquire the potential to save someone else’s life. This could be a newborn too young to be vaccinated, a neighbor, a relative or a close friend. It could even be a friend of a friend, or a stranger you walk by in the grocery store. How often do you have the opportunity to do something so simple that could have such a life-changing impact?

But don’t just take our word for it — ask yourself: “Who in my life do I want to protect from the flu?” Getting vaccinated will help the people you care about stay healthy this flu season. Community immunity is strongest when nearly everyone is getting vaccinated. This year, get vaccinated and share the benefits of the protection you get from the flu vaccine. Don’t share the flu.