Guest
(Full English subtitles are available for this talk — click the CC button in the bottom right of your screen to turn subtitles on.) How do vaccines prevent disease — even among people too young to get vaccinated? It's a concept called “herd immunity,“ and it relies on a critical mass of people getting their shots to break the chain of infection. Health researcher Romina Libster shows how herd immunity contained a deadly outbreak of H1N1 in her hometown. (In Spanish with subtitles.) Visit to get our entire library of TED Talks, transcripts, translations, personalized talk recommendations and more. The TED Talks channel features the best talks and performances from the TED Conference, where the world's leading thinkers and doers give the talk of their lives in 18 minutes (or less). Look for talks on Technology, Entertainment and Design — plus science, business, global issues, the arts and more. You're welcome to link to or embed these videos, forward them to others and share these ideas with people you know. Become a TED Member: Follow TED on Twitter: Like TED on Facebook: Subscribe to our channel: TED's videos may be used for non-commercial purposes under a Creative Commons License, Attribution–Non Commercial–No Derivatives (or the CC BY – NC – ND 4.0 International) and in accordance with our TED Talks Usage Policy (). For more information on using TED for commercial purposes (e.g. employee learning, in a film or online course), please submit a Media Request at
