The flu season may be winding down, but public health experts are already preparing for next season by working on the next vaccine.

The flu season may be winding down, but public health experts are already preparing for next year.

Production is underway for next season's flu vaccine.

It takes about six months for scientists to decide which strains of the virus to include in the vaccine, grow them in eggs, and then turn them into a vaccine ready for distribution in the fall.

The problem is that the virus can mutate and change during those six months, making the vaccine less effective. 

Dr. Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases, said that advancing vaccine technology is critical.

"You want to make the body make a response against the part of the virus that doesn't change from season to season," he said. "We know there's a part of the virus that always drifts or changes from season to season. We want to make a vaccine that induces a response to a part of the virus that doesn't change."

The 2017-2018 flu season has been one of the worst seasons in years.