Protection of Humans against Malaria by Immunization with Radiation-Attenuated Plasmodium falciparum Sporozoites

SL Hoffman, LML Goh, TC Luke… - The Journal of …, 2002 - academic.oup.com
SL Hoffman, LML Goh, TC Luke, I Schneider, TP Le, DL Doolan, J Sacci, P De la Vega…
The Journal of infectious diseases, 2002academic.oup.com
Abstract During 1989–1999, 11 volunteers were immunized by the bites of 1001–2927
irradiated mosquitoes harboring infectious sporozoites of Plasmodium falciparum (Pf) strain
NF54 or clone 3D7/NF54. Ten volunteers were first challenged by the bites of Pf-infected
mosquitoes 2–9 weeks after the last immunization, and all were protected. A volunteer
challenged 10 weeks after the last immunization was not protected. Five previously
protected volunteers were rechallenged 23–42 weeks after a secondary immunization, and …
Abstract
During 1989–1999, 11 volunteers were immunized by the bites of 1001–2927 irradiated mosquitoes harboring infectious sporozoites of Plasmodium falciparum (Pf) strain NF54 or clone 3D7/NF54. Ten volunteers were first challenged by the bites of Pf-infected mosquitoes 2–9 weeks after the last immunization, and all were protected. A volunteer challenged 10 weeks after the last immunization was not protected. Five previously protected volunteers were rechallenged 23–42 weeks after a secondary immunization, and 4 were protected. Two volunteers were protected when rechallenged with a heterologous Pf strain (7G8). In total, there was protection in 24 of 26 challenges. These results expand published findings demonstrating that immunization by exposure to thousands of mosquitoes carrying radiation-attenuated Pf sporozoites is safe and well tolerated and elicits strain-transcendent protective immunity that persists for at least 42 weeks.
Oxford University Press