Experimental infection and protection against ... - TI Pharma

Summary, Samenvatting, List of publications, Dankwoord, C.V. 247
pluripotent effector memory T-cells. We showed that protection lasts for more
than two years in four of six re-challenged volunteers and found a markedly
delayed patency in the two remaining volunteers (Chapter 10). Whereas the
methodology described here does not itself represent a widely implementable
vaccine strategy, the induction of protection against an homologous malaria
challenge suggests that the concept of a whole parasite malaria vaccine
warrants further consideration. However, the development of a whole
sporozoite vaccine requires the development of an in vitro sporozoite potency
test, in order to ensure the complete attenuation of the vaccine. Recent results
with multiply genetically-attenuated parasite lines leading to blood-infection,
are a signal to scientists to take a prudent approach before administering live
vaccine products to large populations.
In conclusion, a more careful approach incorporating immunological research
elucidating mechanisms of protection and enhancing efficacy through antigenadjuvant
combinations may be warranted for the subunit AMA1 vaccine
candidate, whereas the promising efficacy results of the CPS immunisation
strategy might stimulate a more pragmatic approach to develop an
implementable whole-organism based vaccine. Controlled human infection trials
performed in small numbers of subjects will provide a valuable tool accelerating
the development of malaria vaccines.