Safety, Immunogenicity, and Protective Efficacy of Intradermal Immunization with Aseptic, Purified, Cryopreserved Plasmodium falciparum Sporozoites in Volunteers Under Chloroquine Prophylaxis: A Randomized Controlled Trial.
Am J Trop Med Hyg
; 94(3): 663-673, 2016 Mar.
Article
em En
| MEDLINE
| ID: mdl-26711509
ABSTRACT
Immunization of volunteers under chloroquine prophylaxis by bites of Plasmodium falciparum sporozoite (PfSPZ)-infected mosquitoes induces > 90% protection against controlled human malaria infection (CHMI). We studied intradermal immunization with cryopreserved, infectious PfSPZ in volunteers taking chloroquine (PfSPZ chemoprophylaxis vaccine [CVac]). Vaccine groups 1 and 3 received 3× monthly immunizations with 7.5 × 10(4) PfSPZ. Control groups 2 and 4 received normal saline. Groups 1 and 2 underwent CHMI (#1) by mosquito bite 60 days after the third immunization. Groups 3 and 4 were boosted 168 days after the third immunization and underwent CHMI (#2) 137 days later. Vaccinees (11/20, 55%) and controls (6/10, 60%) had the same percentage of mild to moderate solicited adverse events. After CHMI #1, 8/10 vaccinees (group 1) and 5/5 controls (group 2) became parasitemic by microscopy; the two negatives were positive by quantitative real-time polymerase chain reaction (qPCR). After CHMI #2, all vaccinees in group 3 and controls in group 4 were parasitemic by qPCR. Vaccinees showed weak antibody and no detectable cellular immune responses. Intradermal immunization with up to 3 × 10(5) PfSPZ-CVac was safe, but induced only minimal immune responses and no sterile protection against Pf CHMI.
Texto completo:
1
Coleções:
01-internacional
Contexto em Saúde:
1_ASSA2030
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2_ODS3
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3_ND
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4_TD
Base de dados:
MEDLINE
Assunto principal:
Plasmodium falciparum
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Cloroquina
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Malária Falciparum
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Esporozoítos
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Antimaláricos
Tipo de estudo:
Clinical_trials
Limite:
Adolescent
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Adult
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Animals
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Humans
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Male
Idioma:
En
Revista:
Am J Trop Med Hyg
Ano de publicação:
2016
Tipo de documento:
Article