Safety and Differential Antibody and T-Cell Responses to the Plasmodium falciparum Sporozoite Malaria Vaccine, PfSPZ Vaccine, by Age in Tanzanian Adults, Adolescents, Children, and Infants.
Am J Trop Med Hyg
; 100(6): 1433-1444, 2019 06.
Article
em En
| MEDLINE
| ID: mdl-30994090
ABSTRACT
In 2016, there were more cases and deaths caused by malaria globally than in 2015. An effective vaccine would be an ideal additional tool for reducing malaria's impact. Sanaria® PfSPZ Vaccine, composed of radiation-attenuated, aseptic, purified, cryopreserved Plasmodium falciparum (Pf) sporozoites (SPZ) has been well tolerated and safe in malaria-naïve and experienced adults in the United States and Mali and protective against controlled human malaria infection with Pf in the United States and field transmission of Pf in Mali, but had not been assessed in younger age groups. We, therefore, evaluated PfSPZ Vaccine in 93 Tanzanians aged 45 years to 6 months in a randomized, double-blind, normal saline placebo-controlled trial. There were no significant differences in adverse events between vaccinees and controls or between dosage regimens. Because all age groups received three doses of 9.0 × 105 PfSPZ of PfSPZ Vaccine, immune responses were compared at this dosage. Median antibody responses against Pf circumsporozoite protein and PfSPZ were highest in infants and lowest in adults. T-cell responses were highest in 6-10-year olds after one dose and 1-5-year olds after three doses; infants had no significant positive T-cell responses. The safety data were used to support initiation of trials in > 300 infants in Kenya and Equatorial Guinea. Because PfSPZ Vaccine-induced protection is thought to be mediated by T cells, the T-cell data suggest PfSPZ Vaccine may be more protective in children than in adults, whereas infants may not be immunologically mature enough to respond to the PfSPZ Vaccine immunization regimen assessed.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Contexto em Saúde:
1_ASSA2030
/
2_ODS3
/
3_ND
/
4_TD
/
7_ODS3_muertes_prevenibles_nacidos_ninos
Problema de saúde:
1_doencas_transmissiveis
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2_enfermedades_transmissibles
/
2_muertes_prevenibles
/
3_malaria
/
3_neglected_diseases
/
4_malaria
/
7_infections
Assunto principal:
Plasmodium falciparum
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Anticorpos Antiprotozoários
/
Linfócitos T
/
Malária Falciparum
/
Vacinas Antimaláricas
Tipo de estudo:
Clinical_trials
Limite:
Adolescent
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Adult
/
Child
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Child, preschool
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Female
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Humans
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Infant
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Male
/
Middle aged
País/Região como assunto:
Africa
Idioma:
En
Revista:
Am J Trop Med Hyg
Ano de publicação:
2019
Tipo de documento:
Article
País de afiliação:
Tanzânia