He and his colleagues say flu season started early this year, and the dominant strain of the virus that has emerged is the H3N2. That's the same strain that pinballed around the world last flu season and wreaked havoc in Australia during the southern hemisphere's winter months.
According to the CDC, more than 6,000 people have tested positive for the flu so far this year, more than double the number of people infected at this time last year.
"The H3N2 strain tends to make for a more severe disease, particularly among older people and people with underlying illness," Schaffner said. "But it can affect any child or adult and literally make them gravely ill within 48 hours, to the point where they have to be in the hospital, in intensive care. This can and does happen."
For people suddenly stressed out about a sudden high temperature or dry cough, there is an easy and inexpensive way to prevent influenza: annual vaccinations.
Schaffner, a self-proclaimed proselytizer of the flu-shot gospel, told The Washington Post flu shots can cut the chance of infection in half. For vaccinated people who end up getting the flu, it typically makes the symptoms milder. Lastly, getting the shot decreases a person's chances of passing the flu on to other people, including vulnerable groups such as children and the elderly.
According to The Post's Samantha Schmidt, a recent study showed vaccinations significantly reduced a child's chances of dying from the flu.
"Every year CDC receives reports of children who died from the flu. This study tells us that we can prevent more of these deaths by vaccinating more," Brendan Flannery, PhD, lead author and epidemiologist in the Influenza Division, said in a CDC statement.
Murrieta did not get a flu shot, her family told CBS News, but doctors say there's no way of knowing whether it would have made a difference for the 20-year-old.
For now, her family has started a GoFundMe page that has raised more than $18,000 of its $20,000 goal by Tuesday. They plan to use it to cover funeral expenses and provide for her two boys — the oldest is 2 years old, the younger 6 months.
"Our family is devastated that she is gone," the page said. " ... Alani left behind so many people that loved her."