title: CDC expands influenza vaccination window, acknowledges supply problems.
mesh_terms: D002487:Centers for Disease Control and Prevention, U.S.; D006801:Humans; D007252:Influenza Vaccines; D007251:Influenza, Human / Q000517:prevention & control*; D013997:Time Factors; D014481:United States
chemical_list: D007252:Influenza Vaccines