(S (S (BASENP (DT A) (JJ parallel) (NN study)) (VP (MD will) (VP (ADVP (RB also)) (VP (VB be) (VP (VP (VBN conducted) (PP (IN in) (NP (BASENP (DT the) (NNP United) (NNPS States)) (CC and) (BASENP (NNP South) (NNP America))))) (COMMA ,) (S (VP (TO to) (VP (VB compare) (NP (NP (BASENP (DT the) (NN vaccine) (POS 's)) (NN effectiveness)) (PP (IN on) (NP (BASENP (JJ various) (NNS strains)) (PP (IN of) (BASENP (NN HIV)))))))))))))) (PERIOD .))