1. Rowland-Jones, S. L. et al. Cytotoxic T cell response to multiple conserved HIV epitopes in HIV-resistant prostitutes in Nairobi. J. Clin. Invest. 102, 1758–1765 (1998).
2. Saag, M. S. et al. Extensive variation of human immunodeficiency virus type-1 in vivo. Nature 334, 440–444 (1988).
3. Melnick, J. L. in Fields Virology (eds Fields, B. N., Knipe, D. M. & Howley, P. M.) 655–712 (Lippincott-Raven, Philadelphia, 1996).
4. Chanock, R. M. Reminiscences of Albert Sabin and his successful strategy for the development of the live oral poliovirus vaccine. Proc. Assoc. Am. Phys. 108, 117–126 (1996).
5. Luciw, P. A. in Fields Virology (eds Fields, B. N., Knipe, D. M. & Howley, P. M.) 1881–1952 (Lippincott-Raven, Philadelphia, 1996).