Jessica Richman felt fear rush over her – again. In October, she watched her 3-year-old daughter, Layla, become unusually lethargic, develop a high fever and start to have shortness of breath. It was a painful reminder of her other daughter, Cayden, who died of the flu in December 2014. Cayden had been the same age as Layla. “It was very similar symptoms to Cayden. So, of course, I jumped into high gear,” Richman said.

When Layla’s symptoms began on Halloween, Richman took her to an urgent care clinic in their hometown of Newport News, Virginia. “Her heart rate was elevated. Her fever was very high. They kept her there for most of the afternoon to observe her,” Richman said.

“I explained to the doctor that was there that I have lost a 3-year-old daughter to the flu, so this was very scary for me. He really took that to heart. ”

Layla’s medical team diagnosed her with influenza and gave her Motrin for her fever and the antiviral Tamiflu to treat the infection. “She felt better fairly quickly, within 24 hours,” Richman said. Richman’s experience during this flu season was dramatically different than in 2014, when she lost her beloved Cayden. One key difference: Cayden was unvaccinated in 2014. Layla got her vaccine in September.

“I really think that the vaccine played a big role,” said Richman, who serves as secretary for the nonprofit Families Fighting Flu. Even though Layla became sick when she encountered the flu virus weeks after vaccination, “she recovered quickly,” Richman said, adding that no one else in their household – which also includes her husband, Matt, and their 6-year-old son, Parker – caught the flu from Layla.

All of them had been vaccinated before Layla’s illness.

The US Centers for Disease Control and Prevention estimates that at least 16,000 people have died of flu this season, and at least 79 deaths have been in children. Seasonal flu activity continues to be very prevalent across the United States but has been declining in most areas in recent weeks. Still, public health officials encourage people to get their annual flu vaccine as the best way to protect against that virus.

Many people who don’t get their seasonal flu shot are not necessarily anti-vaccination. They simply might not have had the time. That was the case for Cayden in 2014. That year, Richman and Cayden’s father got their flu shots, but Cayden’s vaccination had to be rescheduled because she had a cold at the time.

“Because I also at the time was ill-informed about the flu, I didn’t feel that it was super urgent to go and immediately get her flu shot as soon as she was well,” Richman said. “I kind of put it off.”

One Thursday some weeks later, Cayden wasn’t her usual talkative and bubbly self. The 3-year-old, affectionately known as CadyBug, was fatigued and developed a cough. She stayed home from daycare with her father, and he took her to the pediatrician’s office. The doctor thought Cayden’s symptoms were probably from a cold virus and sent her home without testing for the flu, Richman said.

Just two days later, Cayden was rushed to the hospital with a fever of 106 degrees, and her condition quickly deteriorated.