the administration of 0.4 micrograms of polyribosylribitol phosphate ( prp ) combined with pertussis vaccine or with diphtheria toxoid-tetanus toxoid-pertussis vaccine ( dtp ) to infant rats at 5 , 10 , and 15 days of age resulted in significant ( p less than 0.001 ) protection against hib bacteremia after challenge at 20 days of age .
C0031237
pertussis vaccine
C1875033
diphtheria toxoid-tetanus toxoid-pertussis