2 research outputs found
Proceso para el desarrollo de una vacuna contra la fase hepática de Plasmodium vivax
Introducción: Anualmente se producen en el mundo entre 80 y 100 millones de casos de malaria
ocasionada por Plasmodium vivax, segunda especie de Plasmodium en importancia a nivel mundial y
primera en el continente americano. Ante la falla de los métodos clásicos de control de la malaria,
derivada de la creciente resistencia de los mosquitos a los insecticidas y de los parásitos a los
medicamentos disponibles, se ha trabajado intensamente en la búsqueda de vacunas que puedan
prevenir completamente la infección o limitar los efectos patológicos de la enfermedad.
Objetivos: Este trabajo describe el proceso de desarrollo de una vacuna experimental dirigida contra
las formas pre-eritrocíticas del parásito, para lo cual se ha seleccionado la proteína circumesporozoito
(CS) que se expresa de forma abundante en la superficie del parásito y que se halla comprometida en
el proceso de invasión hepática.
Metodología: El proceso consistió en una exhaustiva caracterización inmunológica de la proteína,
mediante péptidos sintéticos de diferente longitud, seguida de pruebas de toxicidad e inmunogenicidad
en animales con los tres péptidos largos que cubren las regiones N, R y C de la CS. Como etapa inicial
de la prueba en humanos, se hizo un ensayo clínico fase I que probó la seguridad e inmunogenicidad,
de cada uno de los péptidos formulados en el adyuvante Montanide ISA-720. El ensayo fue al azar, doble
ciego y comprometió a 23 voluntarios sanos, hombres y mujeres entre 18 y 33 años de edad, sin historia
de malaria.
Conclusiones: La vacuna fue muy bien tolerada y demostró buena seguridad e inmunogenicidad en los
ensayos preclínicos así como en todos los voluntarios, facilitando el avance a ulteriores fases de
investigación clínica. Introduction: Plasmodium vivax causes approximately
80-100 million clinical cases every year. It is the most
prevalent human malaria parasite in the American continent
and its prevalence is second only to P. falciparum worldwide.
Due to the emergence of medication-resistant parasites and
an increase in insecticide-resistant mosquitoes, research to
find a vaccine that could prevent or limit the clinical
manifestations of the disease has increased greatly. During
the last two decades, significant progress has been achieved
in this attempt; however, the development of a P. vivax
vaccine has been hampered due to the lack of sustainable in
vitro parasite cultures.
Objectives: We describe the development and testing of
a vaccine to P. vivax pre-erythrocytic stages. We selected
the circumsporozoite (CS) protein, an antigen abundantly
expressed on the parasite surface.
Methodology: After extensive immunological characterization
in vitro, three long peptides (N, R and C) were
synthesized, and the toxicity and immunogenicity of these
peptides were thoroughly assessed in animals. To determine
the safety and immunogenicity in humans, a randomized,
double blind clinical trial was conducted. The trial included
23 healthy volunteers who received 100 μg of N, R and C of
each peptide formulated in Montanide ISA-720 adjuvant.
Conclusions: The vaccination was well tolerated and
proven to be safe in both animals and volunteers; thus,
additional clinical trials utilizing this vaccine candidate are
indicated
Proceso para el desarrollo de una vacuna contra la fase hepática de Plasmodium vivax
Introduction: Plasmodium vivax causes approximately 80-100
million clinical cases every year. It is the most prevalent human
malaria parasite in the American continent and its prevalence is second
only to P. falciparum worldwide. Due to the emergence of
medication-resistant parasites and an increase in insecticide-resistant
mosquitoes, research to find a vaccine that could prevent or limit the
clinical manifestations of the disease has increased greatly. During
the last two decades, significant progress has been achieved in this
attempt; however, the development of a P. vivax vaccine has been
hampered due to the lack of sustainable in vitro parasite cultures.
Objectives: We describe the development and testing of a vaccine to P.
vivax pre-erythrocytic stages. We selected the circumsporozoite (CS)
protein, an antigen abundantly expressed on the parasite surface.
Methodology: After extensive immunological characterization in vitro,
three long peptides (N, R and C) were synthesized, and the toxicity and
immunogenicity of these peptides were thoroughly assessed in animals.
To determine the safety and immunogenicity in humans, a randomized,
double blind clinical trial was conducted. The trial included 23
healthy volunteers who received 100 μg of N, R and C of each
peptide formulated in Montanide ISA-720 adjuvant. Conclusions: The
vaccination was well tolerated and proven to be safe in both animals
and volunteers; thus, additional clinical trials utilizing this vaccine
candidate are indicated