Mask are effective but not completely if you look towards the scientific aspects the virus is smaller than any pores of any mask (including N95 mask) which means the virus can penetrate any mask and
secondly about the vaccine development process is still on and many countries including America, Russia and India have shown postive results
According to me the vaccine wilp be available in December end, most probably
I started wearing the masks since day one even without the CDC recommending it to the American people. That’s what they did in China and Korea and other countries to slow the spread and cases. So the masks are effective. The vaccine would be rushed, so many are hesitant to get the vaccine.
The way he worded it doesn't mean the vax won't do the job for the general population overall, just that for specific vaxxed individuals in the 30% that it doesn't work for (or whatever % it ends up working out to) group who end up exposed then a mask would have given some protection because the mask has a higher % of providing safety. He is effectively stating if you just do one of the 2, the odds of not getting it are better if you mask than vax - of course a person terrified of Covid (but not scared of the vax) can do both.
His vax rollout timeline is next year. Stay tuned.
https://www.cnn.com/2020/09/16/politics/donald-trump-coronavirus-masks-health-experts/index.html