pharmaceutical company, being administered at zoos around the country under emergency use. >> given how sick the cats got, you must be very relieved that there is a vaccine available. >> yes. it's really a game changer. but i know that those of us that are getting the animals vaccinated, especially those of us that have dealt with these situations, are feeling a lot happier than we did six months ago. >> the great cats will get their shots in about 90 days. doses of hope that they will stay healthy. >> weijia jiang, cbs news, washington. >> how beautiful are those animals. next on, cbs weekend news, greta thunberg stakes a surpriseing spin on the world stage.