Olivia Twenty Dahl (20 April 1955 – 17 November 1962) was the oldest child of the author Roald Dahl and the American actress Patricia Neal. She died at the age of seven from encephalitis caused by measles, before a vaccine against the disease had been developed. Roald Dahl's books James and the Giant Peach (1961) and The BFG (1982) were dedicated to Olivia. As a result of her death, her father Roald became an advocate for vaccination, and wrote the pamphlet "Measles: A Dangerous Illness" in 1988.

Kilde:
https://en.wikipedia.org/wiki/Olivia_Dahl

Døde av meslinger og inflamasjon i en alder av syv år.

Kilde: http://www.dagbladet.no/2015/02/04/nyheter/roald_d.../meslinger/37516880/