Plasmodium falciparum-specific cellular immune responses after immunization with the RTS,S/AS02D candidate malaria vaccine in infants living in an area of high endemicity in Mozambique.
Infect Immun
; 77(10): 4502-9, 2009 Oct.
Article
em En
| MEDLINE
| ID: mdl-19651872
ABSTRACT
Results from clinical trials in areas where malaria is endemic have shown that immunization with RTS,S/AS02A malaria vaccine candidate induces partial protection in adults and children and cellular effector and memory responses in adults. For the first time in a malaria vaccine trial, we sought to assess the cell-mediated immune responses to RTS,S antigen components in infants under 1 year of age participating in a clinical phase I/IIb trial of RTS,S/AS02D in Mozambique. Circumsporozoite protein (CSP)-specific responses were detected in approximately half of RTS,S-immunized infants and included gamma interferon (IFN-gamma), interleukin-2 (IL-2), and combined IL-2/IL-4 responses. The median stimulation indices of cytokine-producing CD4(+) and CD8(+) cells were very low but significantly higher in RTS,S-immunized infants than in infants that received the comparator vaccine. Protection against subsequent malarial infection tended to be associated with a higher percentage of individuals with CSP-specific IL-2 in the supernatant (P = 0.053) and with higher CSP-specific IFN-gamma-producing CD8(+) T-cell responses (P = 0.07). These results report for the first time the detection of malaria-specific cellular immune responses after vaccination of infants less than 1 year of age and pave the way for future field studies of cellular immunity to malaria vaccine candidates.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Plasmodium falciparum
/
Leucócitos Mononucleares
/
Subpopulações de Linfócitos T
/
Malária Falciparum
/
Vacinas Antimaláricas
Tipo de estudo:
Clinical_trials
Limite:
Adult
/
Animals
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Female
/
Humans
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Infant
/
Newborn
/
Pregnancy
País/Região como assunto:
Africa
Idioma:
En
Revista:
Infect Immun
Ano de publicação:
2009
Tipo de documento:
Article
País de afiliação:
Moçambique