(Research scientists) may complete enrollment of a (phase i) of a vaccine.
Some categories can be constituted-of-or-filled-with (class i devices).
A government-agency may exempt some categories of (class i devices) from notification.
An (assistant i) may be mentioned at a beginning of remarks.
Subsets can be constituted-of-or-filled-with (stage i lung cancer patients).
(Phase i trials) of a (candidate vaccine) may be accelerated.