Definition: In this task, you will be presented with a passage and have to answer a question based on your understanding of the events inferred from the passage. Try to find the best answer that is most likely to fill in "_". Note that the URLs in the text have been replaced with [Link].
Input: He may be known for his party-loving ways, but Prince Harry works tirelessly to help vulnerable children living in extreme poverty at risk of AIDS - and now his services are being recognised. As part of his Sentebale charity, which he set up with Prince Seeiso of Lesotho, the 30-year-old royal built the Mamohato Children’s Centre to support vulnerable children through healthcare and education. And now, Harry's programme will be receiving the 2015 Swarovski Crystal Of Hope Award at the glittering Life Ball event in May. Prince Harry, who set up Sentebale, a charity that provides healthcare and education to vulnerable children in Lesotho, Southern Africa, will be honoured with an award for his servicesAs part of his Sentebale charity Harry built the Mamohato Children's CentreTo be awarded 2015 Swarovski Crystal Of Hope Award at Life BallIs biggest charity event in Europe supporting people with HIV or AIDSPrevious guests include Bill Clinton and Antonio Banderas 
 Question:'It has been twenty years since he was part of the Life Ball and we are at such an exciting time in our medical fight against _ that his presence is a wonderful reminder of how far we have come.'

AIDS