( ( The cell ) ( then ( ( ( ( bursts open ) , ) ( spreading ( the virus ) ) ) . ) ) )
(ROOT (S (NP (DT The) (NN cell)) (ADVP (RB then)) (VP (VBZ bursts) (ADJP (JJ open)) (, ,) (S (VP (VBG spreading) (NP (DT the) (NN virus))))) (. .)))
The cell then bursts open, spreading the virus.
(ROOT (S (NP (NNP Tamiflu)) (VP (VBZ inhibits) (NP (NP (NN spread)) (PP (IN of) (NP (NN virus))))) (. .)))