The term 'Flu Fighters' refers to medical professionals who are dedicated to preventing and treating the flu. Two of the crossword solutions for this term are 'SHOTS' (5 letters) and 'SERA' (4 letters). 'SHOTS' is a reference to the flu vaccine, which is an injection of weakened flu viruses that helps the body build immunity against the disease. 'SERA' is an acronym for serum, which is a type of blood product that contains antibodies that can help fight off the flu virus.