Alex Sigal was born in the Soviet Union and grew up in Israel, the US, and Canada. He completed his MSc studies at the Weizmann Institute in Israel and travelled eastern Africa by bicycle, where he witnessed the impact of the HIV epidemic. He then returned to Weizmann to do his PhD. Following his PhD studies, Sigal joined David Baltimore at the California Institute of Technology to study HIV. Here, his interests in infectious disease matured towards understanding why chronic infections such as HIV and TB cannot be cleared by the immune response and in the case of HIV, by current antiretroviral therapy regimens. His investigations focussed on cell-to-cell spread in HIV infection. At the Africa Health Research Institute (AHRI) - previously known as K-RITH (the KwaZulu-Natal Research Institute for Tuberculosis and HIV) – Sigal’s group works on reservoirs of infection in HIV and TB both by experiments in his lab, computational approaches, and samples from cohorts of infected individuals uniquely available through AHRI.