Thank you for posting your question. Before answering your question, I would like to make two points. Firstly, viral fever per se is a very vague terminology and doesn t really point towards any specific disease process. Secondly, most of the viruses do not have any specific treatment and drugs are usually directed towards preventing further complications. However for a child aged 14 yrs who is on a ventilator with normal reports and doctors suggesting its viral fever, I can think of two possibilities. One of them is viral encephalitis which is a viral infection of the brain. It is a condition with varied presentations often requiring ventilator support. It could occur due to a variety of viruses, most of which do not have any specific treatment, except one. If a herpes virus encephalitis is suspected a drug called acyclovir may be used. Second possibility i can think of is a viral pneumonia probably secondarily infected by bacteria. In this case antibiotic coverage with antiviral drugs like oseltsmivir may be tried. If you could provide more clear details of the case, it would be easier to guide you. I wish your nephew an early recovery.