A malaria protein containing vaccinia virus provokes mice toproduce antibodies that prevent the transmission of malaria.
National Institutes of Health researchers constructed avaccinia virus containing the Pfs25 gene of the parasitePlasmodium falciparum. Pfs25 is a sexual-stage surfaceparasite protein that is the target for antibodies that preventthe transmission of malaria between a vertebrate host and amosquito.
The NIH team reported in Friday's issue of Science thattransmission-blocking antibodies bind to cells infected withPfs25-containing vaccinia virus (Pfs25-VV). This indicatesthat the cells are expressing the native form of Pfs25.
The researchers introduced the Pfs25-VV into mice andshowed that the mice could produce Pfs25 antibodies. Multipleinoculations were required for mice to produce sufficientantibodies to block transmission of the malaria parasite.
Still to be determined is whether this vaccine will induce theproduction of sufficient antibodies in humans.
The authors point out that Pfs25-VV, which is a liveattenuated virus, has advantages over subunit vaccinesbecause live viruses are inexpensive to produce and are easilytransported and administered.
-- Carol Talkington Verser, Ph.D. Special to BioWorld
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