▁confused , ▁fr ustr ated , ▁and ▁uns ure ▁of ▁which ▁sources ▁of ▁information ▁are ▁trust worth y . ▁Add itional ▁recommend ations ▁include ▁introdu cing ▁parents ▁to ▁the ▁importance ▁of ▁v acc ination ▁as ▁far ▁in ▁advance ▁of ▁the ▁initial ▁well - child ▁visit ▁as ▁possible ; ▁present ing ▁parents ▁with ▁v acc ine ▁safety ▁information ▁while ▁in ▁their ▁ped iat ric ian ' s ▁waiting ▁room ; ▁and ▁using ▁pr en atal ▁open ▁houses ▁and ▁post part um ▁mat ern ity ▁w ard ▁vis its ▁as ▁opportun ities ▁to ▁v acc inate . ▁ ▁Internet ▁advert ising , ▁on ▁Facebook ▁and ▁elsewhere , ▁is ▁purchased ▁by ▁both ▁public ▁health ▁authorities ▁and ▁anti - v acc ination ▁groups . ▁In ▁the ▁United ▁States , ▁the ▁majority ▁of ▁anti - v acc ine ▁Facebook ▁advert ising ▁in ▁December ▁ 2 0 1 8 ▁and ▁February ▁ 2 0 1 9 ▁had ▁been ▁paid ▁for ▁one ▁of ▁two ▁groups : ▁Robert ▁F . ▁Kennedy ▁Jr .' s ▁Children ' s ▁Health ▁Def ense ▁and ▁Stop ▁Mand atory ▁V acc ination . ▁The ▁ad s ▁target ed ▁women ▁and ▁young ▁cou ples ▁and ▁generally ▁highlight ed ▁the ▁alleg ed ▁ris ks ▁of ▁v acc ines , ▁while ▁asking ▁for ▁don ations . ▁Several ▁anti - v acc ination ▁advert ising ▁campaign s ▁also ▁target ed ▁areas ▁where ▁meas les ▁out break s ▁were ▁under way ▁during ▁this ▁period . ▁The ▁impact ▁of ▁Facebook ' s ▁subsequent ▁advert ising ▁policy ▁changes ▁has ▁not ▁been ▁studied .