1. Anderson, R. M. & May, R. M. Infectious Diseases of Humans (Oxford Univ. Press, Oxford, 1991).
2. McLean, S. A. & Blower, S. M. Imperfect vaccines and herd immunity to HIV. Proc. R. Soc. Lond. B 256, 9–13 (1993).
3. Halloran, M. E., Struchiner, C. J. & Spielman, A. Modeling malaria vaccines II: Population effects of stage-specific malaria vaccines dependent on natural boosting. Math. Biosci. 96, 115–149 (1989).
4. Hoffman, S. L. Malaria Vaccine Development: A Multi-immune Response Approach (American Society for Microbiology Press, Washington DC, 1996).
5. McLean, A. R. Vaccination, evolution and changes in the efficacy of vaccines: a theoretical framework. Proc. R. Soc. Lond. B 266, 389–393 (1995).