Some health experts are predicting a bad flu season ahead. Cases of the flu are already being diagnosed across the country. Last year’s flu season peaked in December and then again in February. This year’s flu season appears to be starting even earlier.

One of the best ways to avoid contracting the flu is to get a flu shot. Health officials urge nearly all Americans over the age of 6 months to get an annual flu shot. The shots are highly recommended for the young, the elderly, and those with weakened immune systems. Flu shots are also one of the few vaccinations also recommended during pregnancy, when it will protect both the mother and baby.

The flu vaccine does not contain a live virus and it cannot cause you to develop the flu. Mild reactions to a flu shot are common and may include soreness or swelling at the injection site, fever, fatigue, and muscle pain. These side effects generally resolve themselves within a few days of the vaccination.

People who are not feeling well or are exhibiting a fever should wait until they are feeling better before getting their annual flu shot. Individuals who have had severe allergic reactions to a flu vaccine should not get the vaccine again, according to the Centers for Disease Control and Prevention. People should be vaccinated in a medical setting with a provider present who can recognize and manage an emergency reaction.

Young people are more likely than older people to go out in public while feeling sick. When a person who has influenza goes out, they are spreading the virus everywhere they go. Many may think some of their symptoms are just extended cold-like symptoms and underestimate how long it takes to recover from it. The flu is typically contagious for about a week, but the period when you can spread it starts the day before you begin feeling sick.

Data from the federal government shows less than half of all Americans got a flu shot last year. The number of hospitalizations for flu-linked conditions since 2010 is estimated to be as high as 710,000. Dr. Joe Bresee, with the Centers for Disease Control and Prevention, said last year, “If the message to protect yourself is not effective, maybe do it to be a good community member.”