Dr Anna Coussens is a Postdoctoral Research Fellow at the University of Cape Town. She received her PhD from Queensland University of Technology, Australia, in developmental molecular biology. After her PhD she volunteered in Uganda with a Medical Students’ organisation, running health surveys in remote communities. She moved to London where she contributed hugely to a programme of work on vitamin D regulation of the immune response to tuberculosis. Now in Cape Town, she is defining how seasonal UVB patterns affect vitamin D levels in healthy young adults and how this impacts their immune response to HIV-1 infection.