The Smithsonian National Zoo saw a COIVD-19 outbreak among their great cats in September. Nine lions and tigers were infected. One of their older lions almost died from the delta variant of the coronavirus. The variant also caused the Zoo to cancel both Boo at the Zoo and Zoo Lights this year. This week National Zoo Acting Director Dr. Brandie Smith talks about how the great cats got the virus, what role vaccines play for animal health and why the Zoo decided to cancel Boo at the Zoo and Zoo lights.