Flu shot shipments stalled, vaccination period extended.
D000368:Aged; D015276:Health Care Rationing; D006801:Humans; D007252:Influenza Vaccines / Q000008:administration & dosage; D007251:Influenza, Human / Q000517:prevention & control*; D008875:Middle Aged; D014481:United States
D007252:Influenza Vaccines