▁influen cing ▁health ▁policy ▁dec isions ▁for ▁financial ▁gain . ▁In ▁the ▁late ▁ 2 0 th ▁century , ▁v acc ines ▁were ▁a ▁product ▁with ▁low ▁profit ▁marg ins , ▁and ▁the ▁number ▁of ▁companies ▁involved ▁in ▁v acc ine ▁manufact ure ▁decl ined . ▁In ▁addition ▁to ▁low ▁prof its ▁and ▁li ability ▁ris ks , ▁manufact ur ers ▁compla ined ▁about ▁low ▁prices ▁paid ▁for ▁v acc ines ▁by ▁the ▁CD C ▁and ▁other ▁US ▁government ▁ag encies . ▁In ▁the ▁early ▁ 2 1 st ▁century , ▁the ▁v acc ine ▁market ▁greatly ▁improved ▁with ▁the ▁appro val ▁of ▁the ▁v acc ine ▁Pre vn ar , ▁along ▁with ▁a ▁small ▁number ▁of ▁other ▁high - pr iced ▁block b uster ▁v acc ines , ▁such ▁as ▁Gard as il ▁and ▁Ped iar ix , ▁which ▁each ▁had ▁sales ▁reven ues ▁of ▁over ▁$ 1 ▁billion ▁in ▁ 2 0 0 8 . ▁Despite ▁high ▁growth ▁rates , ▁v acc ines ▁represent ▁a ▁relatively ▁small ▁portion ▁of ▁overall ▁ph arma ce ut ical ▁prof its . ▁As ▁recently ▁as ▁ 2 0 1 0 , ▁the ▁World ▁Health ▁Organ ization ▁estimated ▁v acc ines ▁to ▁represent ▁ 2 – 3 % ▁of ▁total ▁sales ▁for ▁the ▁ph arma ce ut ical ▁industry . ▁ ▁War ▁ ▁The ▁United ▁States ▁has ▁a ▁very ▁complex ▁history ▁with ▁comp uls ory ▁v acc ination , ▁particularly ▁in ▁enfor cing ▁comp uls ory ▁v acc in ations ▁both ▁dom est ically ▁and ▁abroad