▁and ▁multiple ▁" bo oster " ▁in jections ▁may ▁be ▁required ▁to ▁provide ▁an ▁effective ▁imm une ▁response ▁against ▁the ▁in activ ated ▁path ogen . ▁Att enu ated ▁v acc ines ▁are ▁often ▁prefer able ▁for ▁generally ▁health y ▁people ▁because ▁a ▁single ▁do se ▁is ▁often ▁safe ▁and ▁very ▁effective . ▁However , ▁some ▁people ▁cannot ▁take ▁at ten u ated ▁v acc ines ▁because ▁the ▁path ogen ▁pos es ▁too ▁much ▁risk ▁for ▁them ▁( for ▁example , ▁elder ly ▁people ▁or ▁people ▁with ▁imm un ode fic iency ). ▁For ▁those ▁patients , ▁an ▁in activ ated ▁v acc ine ▁can ▁provide ▁protection . ▁ ▁Ex amples ▁Types ▁include : ▁ ▁Vir al : ▁pol io ▁v acc ine ▁( S alk ▁v acc ine ) ▁and ▁influen za ▁v acc ine ▁ ▁B acter ial : ▁ty ph oid ▁v acc ine , ▁ch ol era ▁v acc ine , ▁pl ague ▁v acc ine , ▁and ▁pert uss is ▁v acc ine ▁ ▁In activ ated ▁v acc ines ▁are ▁contrast ed ▁with ▁at ten u ated ▁v acc ines , ▁or ▁" live " ▁v acc ines . ▁ ▁Mechan ism ▁The ▁path ogen ▁particles ▁are ▁destroyed ▁and ▁cannot ▁divide , ▁but ▁the ▁path og ens ▁maintain ▁some ▁of ▁their ▁integrity ▁to ▁be ▁recognized ▁by ▁the ▁imm une ▁system ▁and ▁e voke ▁an ▁adapt ive ▁imm une ▁response . ▁ ▁When ▁manufact ured ▁correctly , ▁the ▁v acc ine ▁is ▁not ▁inf ect ious , ▁but