Each year the vaccine contains three inactive virus strains that are most likely to cause illness during the flu season.
(the vaccine; contains; three inactive virus strains that are most likely to cause illness during the flu season; T:Each year) (three inactive virus strains; are; most likely to cause illness during the flu season) (three inactive virus strains; to cause; illness; T:during the flu season)
the vaccine three inactive virus strains three inactive virus strains
contains are to cause
three inactive virus strains that are most likely to cause illness during the flu season T:Each year
most likely to cause illness during the flu season
illness T:during the flu season