Author Roald Dahl is one of the most prolific children's writers of his time. His books often focus on the rise of the underdog. Characters like poor Charlie Bucket and Matilda, from Charlie and the Chocolate Factory and Matilda, go on to find their place in the world, despite all the odds stacked against them. Although his books had happy endings, Dahl's own life had elements of pure tragedy. One of these moments has been recounted in a now viral Facebook post. In the quote which has received tens of thousands of likes and shares on social media, Dahl talks about the passing of his daughter, Olivia in the early sixties.

Dahl, a former WWII pilot, married American actress Patricia Neal in 1953. The couple welcomed Olivia in 1955. Sadly, she would pass away from measles encephalitis aged just seven years old in 1962.  This particular type of illness is caused by the measles virus, which creates inflammation in the brain. To this day, there is still no cure.

Olivia's passing would inspire many of his children's books, and Dahl would continue to talk of her throughout his life. In the late 80s, Dahl penned an open letter to parents urging them to "insist" their children were vaccinated.

An excerpt from the letter has been shared several times on different accounts over the course of the last few days but seems to have originated on Central Coast First Aid Training's Facebook page. The passage, taken from a 1986 interview, is accompanied by a black and white snapshot of the doting father with Olivia before she became ill. Olivia is holding her beloved dog, Rowley.

Many users have been moved by the content, where Dahl describes his sadness at losing his firstborn. Initially, Olivia seemed to be recovering well from measles, but she took an unexpected turn for the worse. Her father was with her when he noticed she couldn't make her hands work properly. The seven-year-old lapsed into a coma, passing away twelve hours later. The original post has over 54,000 likes, 2,700 comments and a staggering 86,878 shares at the time of writing.

Over the course of his life, Dahl encouraged parents to vaccinate their children whenever possible. The first measles vaccine wasn't developed until 1963, a year after Olivia's death.

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