Polytuftsin, a 35-40-unit repeat of the naturally occurring tetrapeptide tuftsin (TKPR), was chemically linked to EENVEHDA and DDEHVEEPTVA repeat sequences of ring-infected erythrocyte surface antigen protein (an asexual blood-stage antigen) of Plasmodium falciparum. These synthetic constructs were tested for their humoral and cellular immune responses in five inbred strains of mice with different genetic backgrounds (H-2a, H-2b, H-2d, H-2k and H-2i). Mice immunized with these constructs showed higher antibody titres, secondary immune responses and antigen-induced T-cell proliferation compared with the peptide dimers alone. Sera from mice immunized with both the constructs inhibited merozoite invasion of erythrocytes in vitro by 60-80% at 1:10 antisera dilution. Polytuftsin alone proved to be a very poor immunogen in our studies, since no anti-tuftsin antibodies could be detected in the sera. Therefore, we conclude that the synthetic constructs described here could be useful for the development of subunit malaria vaccines.
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http://dx.doi.org/10.1016/0264-410x(94)90291-7 | DOI Listing |
Nat Med
January 2025
Leiden University Center for Infectious Diseases, Leiden University Medical Center, Leiden, The Netherlands.
Malaria vaccines consisting of metabolically active Plasmodium falciparum (Pf) sporozoites can offer improved protection compared with currently deployed subunit vaccines. In a previous study, we demonstrated the superior protective efficacy of a three-dose regimen of late-arresting genetically attenuated parasites administered by mosquito bite (GA2-MB) compared with early-arresting counterparts (GA1-MB) against a homologous controlled human malaria infection. Encouraged by these results, we explored the potency of a single GA2-MB immunization in a placebo-controlled randomized trial.
View Article and Find Full Text PDFVaccine
January 2025
Division of Microbiology and Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, MSC 9825, Bethesda, MD 20892-9825, USA. Electronic address:
At the 2023 Global Vaccine and Immunization Research Forum (GVIRF), researchers from around the world gathered in the Republic of Korea to discuss advances and opportunities in vaccines and immunization. Many stakeholders are applying the lessons of Covid-19 to future emergencies, by advancing early-stage development of prototype vaccines to accelerate response to the next emerging infectious disease, and by building regional vaccine research, development, and manufacturing capacity to speed equitable access to vaccines in the next emergency. Recent vaccine licensures include: respiratory syncytial virus vaccines, both for the elderly and to protect infants through maternal immunization; a new dengue virus vaccine; and licensure of Covid-19 vaccines previously marketed under emergency use authorizations.
View Article and Find Full Text PDFChild Care Health Dev
January 2025
Statistics Programme, Bowen University, Iwo, Osun State, Nigeria.
Background: Malaria remains a major cause of preventable deaths among children worldwide, despite the availability of several interventions for controlling and eliminating the disease. The WHO recommended the first malaria vaccine, RTS, S/AS01 in October 2021 to immunize children in sub-Saharan Africa. In this study, we set out to evaluate the knowledge, awareness and acceptability of the malaria vaccine among mothers of under 5 in south-west Nigeria before the vaccine's rollout in Nigeria.
View Article and Find Full Text PDFSci Rep
January 2025
School of Public Health, University of Ghana, Accra, Ghana.
Malaria has been a severe global and public health concern for the last couple of decades. Ghana, like many other countries in sub-Saharan Africa, is most affected by the disease, with children facing dire consequences. The recent introduction of the RTS, S malaria vaccine holds great potential in reducing malaria fatalities in children.
View Article and Find Full Text PDFScience
January 2025
Antibody Biology Unit, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA.
The most advanced monoclonal antibodies (mAbs) and vaccines against malaria target the central repeat region or closely related sequences within the circumsporozoite protein (PfCSP). Here, using an antigen-agnostic strategy to investigate human antibody responses to whole sporozoites, we identified a class of mAbs that target a cryptic PfCSP epitope that is only exposed after cleavage and subsequent pyroglutamylation (pGlu) of the newly formed N terminus. This pGlu-CSP epitope is not targeted by current anti-PfCSP mAbs and is not included in the licensed malaria vaccines.
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