( ( Subsequent studies ) ( ( showed ( Cervarix ( ( ( ( generated ( higher ( antibody levels ) ) ) ( than ( ( Gardasil , ) ( the ( other ( ( commercially available ) ( HPV vaccine ) ) ) ) ) ) ) , ) ( upon ( ( ( ( testing ( seven months ) ) later ) , ) ( with ( ( ( ( twice ( the level ) ) ( for ( HPV type ) ) ) ( ( 16 ( and ( six times ) ) ) ( for HPV ) ) ) ( type 18 ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (JJ Subsequent) (NNS studies)) (VP (VBD showed) (SBAR (S (NP (NNP Cervarix)) (VP (VBD generated) (NP (JJR higher) (NN antibody) (NNS levels)) (PP (IN than) (NP (NP (NNP Gardasil)) (, ,) (NP (DT the) (JJ other) (ADJP (RB commercially) (JJ available)) (NNP HPV) (NN vaccine)))) (, ,) (PP (IN upon) (S (VP (VBG testing) (NP (CD seven) (NNS months)) (ADVP (RB later)) (, ,) (PP (IN with) (NP (NP (ADVP (RB twice) (NP (DT the) (NN level)) (PP (IN for) (NP (NNP HPV) (NN type)))) (NP (CD 16) (CC and) (CD six) (NNS times)) (PP (IN for) (NP (NNP HPV)))) (ADJP (NN type) (CD 18))))))))))) (. .)))
Subsequent studies showed Cervarix generated higher antibody levels than Gardasil, the other commercially available HPV vaccine, upon testing seven months later, with twice the level for HPV type 16 and six times for HPV type 18.
(ROOT (S (NP (NNP Gardasil)) (VP (VBZ is) (NP (DT the) (NN vaccine) (S (VP (TO to) (VP (VB prevent) (NP (NP (NN infection)) (PP (IN of) (NP (NN hpv))))))))) (. .)))