You've just
tried to add this video to your Watchlist so you can watch
it later. But first, we need you to sign in to PBS using one
of the services below.
You’ll be able to manage
videos in your Watchlist, keep track of your favorite shows,
watch PBS in high definition, and much more!
You've just
tried to select this program as one of your favorites. But
first, we need you to sign in to PBS using one of the
services below.
You’ll be able to manage videos in
your Watchlist, keep track of your favorite shows, watch PBS
in high definition, and much more!
To get you
watching PBS in high definition we need you to sign in to
PBS using one of the services below.
You'll be able
to manage videos in your Watchlist, keep track of your
favorite shows, watch PBS in high definition, and much more!
By creating an account, you acknowledge that PBS may share your information with our member stations and our respective service providers, and that you have read and understand the Privacy Policy and Terms of Use.
One More Thing …
Become a WMHT member to enjoy
WMHT | Passport
Look for the blue icon to identify WMHT Passport videos.
As more and more parents are choosing not to vaccinate their children or are vaccinating them later, diseases like measles are making a comeback. Are vaccines safe? How do vaccines work? Why do some people claim there is a link between vaccines and autism? This week we look at why are people afraid of something that has saved so many lives, and look at the history and science of vaccines.