Professor Jeremy Day from our OUCRU unit in Ho Chi Minh City, Vietnam, tells us about his research on central nervous system and HIV infections in Vietnam. Brain infections such as meningitis and encephalitis are highly debilitating diseases, and an accurate diagnostic is essential to give patients the best treatment available. For cryptococcal meningitis, clinical trials focus on prevention, for an early diagnosis, and novel ways to use existing treatments or repurpose old drugs.