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In 2009, hundreds of teenagers\\u2019 lives were changed forever, when a vaccine designed to protect them against swine flu appeared to trigger a sleep disorder.
It affected people in various countries including Sweden.
Maddy Savage speaks to Christopher Tyvi from Stockholm, who is one of those who experienced problems.
A Bespoken Media production for BBC World Service.
(Photo: Swine flu vaccine. Credit: Getty Images)
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