Studies have shown that while the oral polio vaccine contains three strains of polio virus, a fourth strain can be cultured from the faeces of vaccine recipients.
(the oral polio vaccine; contains; three strains of polio virus) (Studies; have shown; that while the oral polio vaccine contains three strains of polio virus, a fourth strain can be cultured from the faeces of vaccine recipients) Context(Studies have shown,List([0, 18))):(a fourth strain; can be; cultured from the faeces of vaccine recipients)
Studies have shown,List([0, 18))
the oral polio vaccine Studies a fourth strain
contains have shown can be
three strains of polio virus
that while the oral polio vaccine contains three strains of polio virus, a fourth strain can be cultured from the faeces of vaccine recipients
cultured from the faeces of vaccine recipients