What to know about flu shots in 2025: Side effects, vaccine ingredients and when to get it

Experts blame misinformation and “vaccine fatigue” for declining demand for flu shots. Here's what you should know about flu vaccines this year.

Jeb Teichman’s phone rang just before midnight. As a pediatrician, he has received many late-night emergency calls.

This time, the call was about his 29-year-old son. Brent Teichman had been suffering from the flu for five days. After he began to recover, his symptoms returned with a vengeance, making it difficult to breathe. Teichman, who was out of town, suggested his son visit an urgent care facility. Brent Teichman returned home from the clinic with a prescription for antibiotics and collapsed in bed.

When his roommate checked on him a few hours later, Brent Teichman was unconscious. His roommate first called Teichman, then 911. The emergency operator instructed the roommate how to perform CPR. When Teichman called the roommate back, he asked the young man to hold the phone so that he could hear emergency responders trying to save his son. “I could hear the monitors beeping,” Teichman said. Six years after his son’s death, Teichman said, “when I close my eyes at night, I still hear that beeping.”

Brent Teichman was 29 when he died in 2019 from flu complications. His father, Dr. Jeb Teichman, said his son’s only risk factor for severe illness was that he didn’t receive a flu shot.Courtesy the subjectAlthough Teichman has retired, he said he is still trying to save lives. He has joined the board of a nonprofit group called Families Fighting Flu, made up of people who have lost loved ones to the illness. As misinformation spreads on social media, Teichman and other health advocates are reminding people of basic facts about the flu.

Based on wastewater samples, the current flu season hasn't taken off yet in the U.S., although once it does, it spreads rapidly across the country, said Alexandria Boehm, program director of WastewaterSCAN, a nonprofit monitoring network and a professor of civil and environmental engineering at Stanford University. "Once it starts in one state it starts everywhere at the same time," she said. "It's not a slow wave."