An FDA advisory panel on Tuesday voted unanimously for a recommendation that the agency adopt a modified flu vaccine for next fall that could make it easier for manufacturers to increase supplies.

The big picture: The panel's recommendation would turn the quadrivalent flu vaccine into a trivalent vaccine — dropping a specific strain that has not been detected since 2020.

• Officials credit influenza immunization programs and the unique environment of the pandemic for its disappearance.

Catch up quick: The seasonal flu vaccine generally is either trivalent or quadrivalent, meaning it either carries three or four strains of the virus, respectively.

• The FDA's Vaccines and Related Biological Products Advisory Committee (VRBPAC) and the World Health Organization set the recommendations for what the vaccines will be comprised of.

Zoom in: VRBPAC on Tuesday recommended that the agency drop the Yamagata part of the flu vaccine.

• Researchers have noted that due to the strain's lineage not being detected for "a prolonged period of time, vaccinating against it would make little or no sense."
• Eliminating the Yamagata strain "would increase the current production capability from approximately 500 million doses" of the quadrivalent vaccine per year to "700 million doses" of the trivalent vaccine "per year instead," researchers added.

Caveat: They still have to keep testing circulating flu viruses in order to ensure that Yamagata has been eliminated and has not resurfaced.

Go deeper: Flu shows signs of a comeback after holiday hiatus