(S (S (BASENP (DT The) (NN virus)) (VP (VBZ has) (VP (VBN been) (VP (ADVP (RB genetically)) (VP (VBN engineered) (S (VP (TO to) (VP (VP (VB prevent) (BASENP (PRP it))) (PP (PP (IN from) (S (VP (VBG causing) (BASENP (DT the) (NN flu))))) (CC or) (PP (IN from) (S (VP (VP (VP (VBG passing) (PRT (RP on))) (PP (IN from) (BASENP (NN person)))) (PP (TO to) (BASENP (NN person))))))))))))))) (PERIOD .))