The Centers for Disease Control and Prevention recommend that everyone over the age of 6 months be vaccinated against influenza (the flu). For those with chronic diseases, pregnant women, and older adults, it is especially important to get vaccinated. Receiving a vaccination is the most effective way to prevent the flu and its complications. We receive many questions about the flu and flu vaccinations; here are the answers to a few:  

What is the flu? The flu is caused by influenza viruses, which infect the nose, throat, and lungs. Unlike the common cold, the flu can cause severe illness and life-threatening complications in many individuals. These complications can often include pneumonia, dehydration, and worsening of chronic medical conditions, such as congestive heart failure, asthma, or diabetes. Children may also develop sinus problems and ear infections as complications from the flu.

How is the flu spread? Experts believe droplets made when individuals who have the flu sneeze or talk spread flu viruses predominantly. These droplets can land in the mouth or nose of people nearby or can be inhaled into the lungs. People with flu can spread it to others up to about 6 feet away. In less frequent situations, an individual touching a surface or object that has the flu virus on it and then touching their own mouth or nose spreads the flu.

Is the flu contagious? The flu is highly contagious. Individuals with the flu may be able to infect others before they realize they’re sick, as well as during the period they are ill. Healthy adults may be able to infect others a day before flu-like symptoms develop and five to seven days after becoming ill. In children, the virus takes one to four days to present symptoms, and during this time, children may be contagious. In addition, children can pass the virus to others for more than seven days.

I received a flu vaccination last year; will I have immunity this year? Not necessarily. Influenza viruses evolve very quickly. Last year’s vaccine may not protect you from this year’s viruses. For optimal protection against the flu, get vaccinated annually regardless of past vaccinations or flu infection.

In addition to getting your vaccination for season-long protection, there are supplementary ways to keep you and your family healthy during the flu season. Be sure to wash your hands often; avoid touching your eyes, nose, and mouth; and stay home if you’re sick.

Dr. Julia Buchkina, M.D., M.P.H.