Ellis is professor emeritus of applied mathematics, University of Cape Town, South Africa. An astronomer and expert in tetrad methods to study cosmological dynamics and Bianchi Universes, he enunciated the dynamical systems approach to cosmology and nonlinear dynamics of cosmic microwave background anisotropies. He has written on the philosophy of cosmology, in particular the multiverse idea. He now works on complexity theory and the nature of the brain. He is a fellow (former president) of the Royal Society of South Africa, Royal Astronomical Society, Academy of Science of South Africa (ASSAf), and Royal Society (London). He is former president of the Intl. Society of General Relativity and Gravitation. He has won: Star of South Africa Medal; Gold Medal, ASSAf; Natl. Science and Technology Forum Lifetime Award; and Templeton Prize. He is a founding member, Inter Academy Council.

Abdool Karim is Pro Vice-Chancellor (Research) at the University of KwaZulu-Natal, in South Africa, and Director of the Centre for the AIDS Programme of Research in South Africa. In the Unites States, he is a Professor of Clinical Epidemiology, at Columbia University and an Adjunct Professor of Medicine at Cornell University. He obtained his medical degree in 1983 and his PhD in 1999 from the University of KwaZulu-Natal. His scientific contributions are in HIV prevention (microbicides and vaccines) and AIDS treatment, including tuberculosis co-infections. His awards include the 2008 TWAS Prize in Medical Sciences; the 2011 Science-for-Society Gold Medals of the Academy of Science of South Africa; the 2015 African Union’s "Kwame Nkrumah Continental Scientific Award”, 2020, he received the Maddox Prize for his work defending science during both the HIV and Covid-19 pandemics, and the 2021 Special VinFuture Prize for Developing Country Innovators. He is a member of the World Health Organization Strategic and Technical Committee on HIV and Viral Hepatitis, the Academy of Science of South Africa, the African Academy of Science, the US National Academy of Medicine, among others.