(S (S (BASENP (PRP It)) (VP (VP (VBZ is) (RB not)) (VP (VBN known) (SBAR (IN whether) (S (S (BASENP (PRP he)) (VP (VBD received) (BASENP (DT a) (NN pneumonia) (NN vaccination)))) (COMMA ,) (SBAR (IN as) (S (VP (VBN recommended) (PP (IN for) (NP (BASENP (NNS people)) (PP (IN of) (BASENP (PRPD his) (NN age))))))))))))) (PERIOD .))