speak tags in VXML 2.0

Hi,

Section 4.1.1 of the VXML 2.0 spec mentions that the contents of the
<prompt> element are modelled on SSML. It does not clearly specify if
the speak tags that SSML requires (<speak> and </speak> in the beginning
and end of the marked up text respectively) are needed within the
<prompt> element in VXML. Do we not need these tags in case of VXML?

Thanks,
Roopa