1. 1. WHO Technical Report Series, No 735, 1986 (WHO Expert Committe on Malaria: eighteenth report). 2. Miller, L. H. et al. Science 234, 1349–1356 (1986). 3. Clyde, D. F., Most, H., McCarthy, V. C. & Vanderberg, J. P. Am. J. med. Sci. 266, 169–177 (1973). 4. Clyde, D. F., McCarthy, V. C., Miller, R. M. & Woodward, W. E. Am. J. trop. Med. Hyg. 24, 397–401 (1975). 5. Rieckmann, K. H., Beaudoin, R. L., Cassels, J. S. & Sell, K. W. Bull. Wld Hlth Org. 57, (Suppl. 1), 261–265 (1979). 6. Nussenzweig, V. & Nussenzweig, R. S. Cell 42, 401–403 (1985). 7. Zavala, F., Cochrane, A. H., Nardin, E. H., Nussenzweig, R. S. & Nussensweig, V. J. exp. Med. 157, 1947–1957 (1983). 8. Dame, J. B. et al. Science 225, 593–599 (1984). 9. Enea, V. et al. Science 225, 628–630 (1984). 10. Zavala, F. et al. Science 228, 1436–1440 (1985). 11. Young, J. F. et al. Science 228, 958–962 (1985). 12. Barany, G. & Merrifield, R. B. The Peptides: Analysis, Synthesis, Biology Vol. 2 (Academic, New York, 1980). 13. Vanderberg, J., Nussenzweig, R. S. & Most, H. Mil. Med. 134, (Suppl.). 1183–1190 (1969). 14. Nardin, E. H., Nussenzweig, R. S., McGregor, I. A. & Bryan, J. H. Science 206, 597–599 (1979). 15. Levine, M. M. et al. J. din. Invest. 79, 888–902 (1986). 16. Burkot, T. R., Williams, J. L. & Schneider, I. Trans. R. Soc. trop. Med. Hyg. 78,339–341 (1984). 17. Lelijveld, J. & Kortman, H. Bull. Wld Hlth Org. 42, 477–479 (1970). 18. Jeffery, G. M., Young, M. D., Burgess, R. W. & Eyles, D. E. Annals trop. Med. Parasit. 53, 51–58 (1959). 19. Boyd, M. F. Symposium on Human Malaria Pub. 15 (American Association for the Advancement of Science, Washington DC, 1941). 20. Nardin, E. H. et al. J. exp. Med. 156, 20–30 (1982). 21. Schmidt, L. H., Fradkin, R., Genther, C. S., Rossan, R. N., Squires, W. & Hughes, H. B. Am. J. trop. Med. Hyg. 31, (Suppl.), 609–703 (1982). 22. Nussenzweig, R. S. Expl Parasit. 21, 224–231 (1967). 23. Zavala, F. et al. J. exp. Med. (submitted). 24. Herzenberg, L. A., Tokuhis, T. & Herzenberg, L. Nature 285, 665–667 (1980). 25. Schutz, M. P., Leclerc, C., Audibert, F. & Chedid, L. /. Immun. 135, 2319–2322 (1985). 26. Sarin, V. K., Kent, S. B. H., Tarn, J. P. & Merrifield, R. B. Analyt. Biochem. 117, 147–157 (1981). 27. Nardin, E. H., Gwadz, R. W. & Nussenzweig, R. S. Bull. Wld Hlth Org. 57 (Suppl. 1), 211–217 (1979). 28. Ballou, R. S. et al. Lancet i, 1277–1281 (1987).