The oral vaccine contains weakened but live polio viruses, as against the original salk vaccine, which is injected and has dead viruses.
(The oral vaccine; contains; weakened) (The oral vaccine; live; polio viruses) (the original salk vaccine; is injected; ) (the original salk vaccine; has; dead viruses)
The oral vaccine The oral vaccine the original salk vaccine the original salk vaccine
contains live is injected has
weakened
polio viruses
dead viruses