It's not too late to get your flu shot, which can protect you in ways that may surprise you.
The flu vaccine can be a lifesaver for people with heart disease, according to infectious disease specialist Dr. Michael Chang, assistant professor of pediatrics at University of Texas Health Science Center at Houston.
"Previous studies have shown influenza vaccination could reduce death, acute coronary syndromes, and hospitalization in patients with coronary heart disease, and/or heart failure," Chang said in a university news release.
"This makes getting your flu shot a no-brainer for anyone with a history of heart disease. It's an extremely cost-effective intervention with lifesaving potential," he said.
The flu shot can also protect you from other nasty infections.
"Your immunity can be altered by having flu, making you more prone to other infections, particularly in the respiratory tract where cells have been damaged. Staph infections are common and mainly not serious, but if you have flu already, Staphylococcus aureus can enter the lungs, causing pneumonia," Chang said.
"That explains why this type of bacterial coinfection is frequent in influenza-associated pneumonia," he said, noting that patients with more than one infection have higher odds for complications and death.
It's not just important for adults to get a flu shot. Having kids vaccinated protects their grandparents and other elderly people, who are at high risk from the flu.
"Children have been described as 'super spreaders' because they come into close contact with family members, and younger ones tend to put their hands in their mouths more, which can put others at greater risk, especially older family members," Chang said.
Children under age 5 are especially vulnerable. Fortunately, the nasal flu spray has returned this year, which should make it easier for little ones who don't like injections, Chang said. Studies show it is just as effective as the shot.
Last year's flu season was the worst in four decades, with more than 80,000 flu or pneumonia-related deaths in the United States.
The U.S. Centers for Disease Control and Prevention has more on flu vaccination.