An 11-year-old boy in New York died on Saturday from flu-related complications, despite getting the seasonal flu vaccine.
Luca Calanni, who just turned 11 last month, was otherwise healthy before contracting the flu earlier in January. His death raises questions about whether the vaccine will actually protect against the flu in the 2019-2020 season.
This season has already been difficult to predict — it started “atypically” early, with at least 9.7 million flu illnesses so far. It has also hit children particularly hard, and Calanni adds to the 32 pediatric flu deaths that the CDC has already reported, the most in 16 seasons by this point in the season.
The main problem, experts say, is that this flu season is led by a strain of influenza B, which is unusual for this time of the year.
“It’s relatively common that we start the season with influenza A, and the influenza B season comes later,” Richard J. Webby, Ph.D., a researcher with the Department of Infectious Disease at St. Jude Children’s Research Hospital, who did not treat Calanni, tells PEOPLE.
Influenza B is also less common overall than influenza A, meaning that people likely have built up fewer antibodies to fight this B strain. This is particularly true for children, who have less exposure to any strains of the flu during their shorter lifespans.
Complicating matters is that the flu vaccine this year is “not ideally matched” to this strain of influenza B, says Webby. Each year, the vaccine is designed with four components — two influenza A antigens and two influenza B antigens — and “we’ve seen quite a bit of vaccine mismatch” to the strain that’s circulating right now.
“The flu vaccine is a good vaccine, but unfortunately it’s not a great vaccine,” Webby says. “So getting the vaccine is not a guarantee, unfortunately, that you won’t get the flu.”
Still, Webby says, it’s extremely important to get the vaccine.
“It does reduce your chances of catching it, and if you do get sick, of getting very severely affected by the virus,” he says. “When we get vaccinated we make a lot of antibodies that will fight against the virus.”
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People need to keep in mind, though, that it is still possible to get the flu after getting the vaccine and to watch out for symptoms.
“If you’re starting to get flu-like symptoms, and you’ve been vaccinated, you shouldn’t assume that you don’t have the flu,” Webby says. “You should still go to the doctor and get tested for influenza.”
And people should know that there is always a risk that they will die from the flu.
“Even when there’s an almost perfect match between the vaccine and virus, there’s still a chance of dying from the disease,” Webby says.