Parents' beliefs about vaccination.
D002648:Child; D002675:Child, Preschool; D006801:Humans; D007223:Infant; D010290:Parents / Q000523:psychology*; D010567:Pertussis Vaccine; D014611:Vaccination; D014917:Whooping Cough / Q000517:prevention & control*
D010567:Pertussis Vaccine