Olivia Dahl

Dahl wrote in the pamphlet that "Today a good and safe vaccine is available to every family and all you have to do is to ask your doctor to administer it". In a 1997 interview Neal recalled the suddenness of Olivia's death, which occurred less than a week after contracting measles. Olivia's sister, Lucy, interviewed in 2015 by CBS, stated that her father did not understand why people chose not to vaccinate their children against measles. In Dahl's public letter, he wrote that it is "'almost a crime' for some parents not to immunize their children". "I do agree with that", Lucy states; "I think that it is a crime".

Neal recalled that a doctor rang to abruptly tell her that Olivia was dead, and she "couldn't believe how cold he was". Neal later regretted not seeing Olivia after her death, having been persuaded not to by her sisters-in-law. According to Neal, her husband "really almost went crazy" with Neal keeping the family together for the sake of their two other children. Neal's grief was helped by talking about Olivia, whereas Roald kept silent about her until his own death in 1990. Olivia was survived by her siblings Theo (born 1960) and Tessa (born 1957). The Dahls' fourth and fifth children, Ophelia and Lucy, were born in 1964 and 1965 respectively. Roald wrote an account of Olivia's death in a notebook which he kept in a drawer of his writing hut; it was discovered after his death 28 years later.

He later became a vaccination advocate, writing an account of Olivia's death in a 1986 pamphlet titled Measles: a dangerous illness for the Sandwell Health Authority. Dahl wrote that .mw-parser-output .templatequote{overflow:hidden;margin:1em 0;padding:0 40px}.mw-parser-output .templatequote .templatequotecite{line-height:1.5em;text-align:left;padding-left:1.6em;margin-top:0}

Olivia came home from her school, Godstowe Preparatory School, in November 1962 with a note informing her parents of an outbreak of measles. Neal contacted her brother-in-law, Ashley Miles, who sent them gamma globulin, then common in the United States, to boost children's immunity against measles. Miles only provided a small amount, which the Dahls used for their son, Theo. Neal recalled in her autobiography, As I Am, that Miles said that "Let the girls get measles...It will be good for them". Olivia subsequently contracted measles, and had a mild fever for a few days before suffering convulsions after growing increasingly lethargic. She quickly became unconscious and was rushed to Stoke Mandeville Hospital where she died the next day.

Roald Dahl donated a wooden statue of Saint Catherine to the Church of St John the Baptist in Little Missenden in memory of Olivia after the original was stolen from the church. Dahl's statue was also subsequently stolen and replaced by a replica. He also dedicated his children's novels James and the Giant Peach (1961) and The BFG (1982) to Olivia. The BFG was published on the twentieth anniversary of her death.

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.

Dahl was born in 20 April 1955 at Doctors Hospital in New York City and grew up in the Buckinghamshire village of Great Missenden. She was named for Olivia, the heroine of William Shakespeare's Twelfth Night, a favourite play by her mother. Her middle name, Twenty, originated from the date of her birth, and the fact that her father had $20 in his pocket when he saw her in the hospital for the first time. Neal struggled with Olivia shortly after her birth but found her behaviour transformed after spending a few weeks with her paternal aunt, Elsie Logsdail. Roald Dahl constructed his writing hut in the orchard of the couple's Gipsy House for peace and quiet to write after her birth.