vaccinated should wear a mask and keep their social distance indoors. we re flying by the seat of our pants here reporter: breaking from cdc guidance, l.a. county is now aligned with the w.h.o., urging universal mask use in public spaces indoors, citing the spread of the delta variant with a new voluntary safety measure. i wanted to wear a mask today reporter: even the illinois governor setting an example, but the backtrack on guidance just before gatherings for the fourth of july is sending mixed messages implementing a mask mandate in the absence of, you know, broader spread of the virus is likely to erode the ability to implement these kinds of measures when we need them we need to give the public a breather. reporter: gaining ground every day the highly contagious and dangerous delta variant now accounts for 26% of covid cases in the u.s and now a new small study says mrna