What is replacement theory and how effective is it as a form of treatment for haemophiliacs? What is Roctavian? How is using a lentivirus as the vector in gene therapy different from using an adenovirus? Are medicines for treating haemophilia affordable and accessible? What is replacement theory and how effective is it as a form of treatment for haemophiliacs? What is Roctavian? How is using a lentivirus as the vector in gene therapy different from using an adenovirus? Are medicines for treating haemophilia affordable and accessible? Health Health News, Wellbeing Tips, Diseases, Treatment and Nutrition | The Hindu