Abstract
We examined the safety, immunogenicity and efficacy of a prime-boost vaccination regime involving two poxvirus malaria subunit vaccines, FP9-PP and MVA-PP, expressing the same polyprotein consisting of six pre-erythrocytic antigens from Plasmodium falciparum. Following safety assessment of single doses, 15 volunteers received a heterologous prime-boost vaccination regime and underwent malaria sporozoite challenge. The vaccines were safe but interferon-γ ELISPOT responses were low compared to other poxvirus vectors, despite targeting multiple antigens. There was no vaccine efficacy as measured by delay in time to parasitaemia. A number of possible explanations are discussed, including the very large insert size of the polyprotein transgene.
Copyright © 2011 Elsevier Ltd. All rights reserved.
Publication types
-
Clinical Trial, Phase I
-
Clinical Trial, Phase II
-
Research Support, Non-U.S. Gov't
MeSH terms
-
Adolescent
-
Adult
-
Antibodies, Protozoan / immunology
-
Antigens, Protozoan / immunology
-
Humans
-
Immunization, Secondary
-
Interferon-gamma / biosynthesis
-
Malaria Vaccines* / administration & dosage
-
Malaria Vaccines* / adverse effects
-
Malaria Vaccines* / immunology
-
Malaria, Falciparum / immunology
-
Malaria, Falciparum / prevention & control
-
Middle Aged
-
Plasmodium falciparum / immunology*
-
Polyproteins / immunology*
-
Protozoan Proteins / immunology*
-
Treatment Outcome
-
Vaccination
-
Vaccines, Subunit / administration & dosage
-
Vaccines, Subunit / adverse effects
-
Vaccines, Subunit / immunology
-
Young Adult
Substances
-
Antibodies, Protozoan
-
Antigens, Protozoan
-
Malaria Vaccines
-
Polyproteins
-
Protozoan Proteins
-
Vaccines, Subunit
-
Interferon-gamma