▁being ▁bur nt ▁to ▁the ▁ground ▁in ▁order ▁to ▁preserve ▁the ▁health ▁and ▁safety ▁of ▁soldiers ▁from ▁en demic ▁small po x ▁and ▁yellow ▁fe ver . ▁V acc ines ▁were ▁for ci b ly ▁admin ister ed ▁to ▁the ▁Puerto ▁Ric ans , ▁Cub ans , ▁and ▁Filip inos . ▁Military ▁personnel ▁in ▁Puerto ▁Rico ▁provided ▁Public ▁Health ▁services ▁that ▁cul min ated ▁in ▁military ▁orders ▁that ▁mand ated ▁v acc in ations ▁for ▁children ▁before ▁they ▁were ▁six ▁months ▁old , ▁as ▁well ▁as ▁a ▁general ▁v acc ination ▁order . ▁By ▁the ▁end ▁of ▁ 1 8 9 9 ▁in ▁Puerto ▁Rico ▁alone ▁the ▁U . S . ▁military ▁and ▁other ▁h ired ▁native ▁v acc in ators ▁called ▁pract ic antes , ▁v acc in ated ▁an ▁estimated ▁ 8 6 0 , 0 0 0 ▁n atives ▁in ▁a ▁five - month ▁period . ▁This ▁period ▁began ▁the ▁United ▁States ' ▁movement ▁toward ▁an ▁expansion ▁of ▁medical ▁practices ▁that ▁included ▁" t rop ical ▁medicine " ▁in ▁an ▁attempt ▁to ▁protect ▁the ▁lives ▁of ▁soldiers ▁abroad . ▁ ▁Information ▁war fare ▁ ▁An ▁analysis ▁of ▁twe ets ▁from ▁July ▁ 2 0 1 4 ▁through ▁September ▁ 2 0 1 7 ▁revealed ▁an ▁active ▁campaign ▁on ▁Twitter ▁by ▁the ▁Internet ▁Research ▁Agency ▁( I RA ), ▁a ▁Russian ▁t roll ▁farm ▁accused ▁of ▁inter ference ▁in ▁the ▁ 2 0 1 6 ▁U . S . ▁elections , ▁to ▁sow ▁disc ord ▁about ▁the ▁safety ▁of ▁v acc