It's all about viruses this week - whilst Matilda's lost her voice,  Dr Sarah Watters demonstrates how the Glitter Virus can spread, and we learn some fascinating things about HIV, 'elite controllers', and the challenges of working on a global project.

Mixtape:

1. One Vision by Queen

2. Toto by Africa

3. PCR Song by Biorad

4. I Am Woman by Helen Reddy

5. Anyway You Want It by Journey

6. Don't Rain On My Parade by Barbara Streisand