Preclinical development of lyophilized self-replicating RNA vaccines for COVID-19 and malaria with improved long-term thermostability.

Messenger RNA (mRNA) vaccines against COVID-19 have demonstrated high efficacy and rapid deployment capability to target emerging infectious diseases. However, the need for ultra-low temperature storage made the distribution of LNP/mRNA vaccines to regions with limited resources impractical. This study explores the use of lyophilization to enhance the stability of self-replicating mRNA (repRNA) vaccines, allowing for their storage at non-freezing temperatures such as 2-8 °C or room temperature (25 °C).

Full maturation of in vitro Plasmodium falciparum oocysts using the AlgiMatrix 3D culture system.

Background: Plasmodium falciparum oocysts undergo growth and maturation in a unique setting within the mosquito midgut, firmly situated between the epithelium and the basal lamina. This location exposes them to specific nutrient exchange and metabolic processes while in direct contact with the mosquito haemolymph. The limited availability of in vitro culture systems for growth of the various P.

Accelerated prime-and-trap vaccine regimen in mice using repRNA-based CSP malaria vaccine.

Malaria, caused by Plasmodium parasites, remains one of the most devastating infectious diseases worldwide, despite control efforts to lower morbidity and mortality. Both advanced candidate vaccines, RTS,S and R21, are subunit (SU) vaccines that target a single Plasmodium falciparum (Pf) pre-erythrocytic (PE) sporozoite (spz) surface protein known as circumsporozoite (CS). These vaccines induce humoral immunity but fail to elicit CD8 + T-cell responses sufficient for long-term protection.

Accelerated prime-and-trap vaccine regimen in mice using repRNA-based CSP malaria vaccine.

Malaria, caused parasites, remains one of the most devastating infectious diseases worldwide, despite control efforts that have lowered morbidity and mortality. The only vaccine candidates to show field efficacy are those targeting the asymptomatic pre-erythrocytic (PE) stages of infection. The subunit (SU) RTS,S/AS01 vaccine, the only licensed malaria vaccine to date, is only modestly effective against clinical malaria.

Accelerated prime-and-trap vaccine regimen in mice using repRNA-based CSP malaria vaccine.

Malaria, caused by parasites, remains one of the most devastating infectious diseases worldwide, despite control efforts that have lowered morbidity and mortality. The only vaccine candidates to show field efficacy are those targeting the asymptomatic pre-erythrocytic (PE) stages of infection. The subunit (SU) RTS,S/AS01 vaccine, the only licensed malaria vaccine to date, is only modestly effective against clinical malaria.

Development of LepReact, a defined skin test for paucibacillary leprosy and low-level M. leprae infection.

The persistence of new leprosy cases in endemic areas such as India, Brazil, Bangladesh, and the Philippines has encouraged studies of chemoprophylaxis among contacts of patients. Epidemiological screening tools to enable early detection of infected individuals in endemic populations would be critical to target individuals most in need of intervention. Despite decades of attempts, however, there still are no tests available for the early detection of low-level infection with Mycobacterium leprae.

Heterologous Immunization With Defined RNA and Subunit Vaccines Enhances T Cell Responses That Protect Against .

The rapid generation of strong T cell responses is highly desirable and viral vectors can have potent CD8 T cell-inducing activity. Immunity to leishmaniasis requires selective T cell responses, with immunization schemes that raise either CD4 or CD8 T cell responses being protective in small animal models. We have defined the leishmaniasis vaccine candidate recombinant fusion antigens, LEISH-F2 and LEISH-F3+, that when formulated in a stable emulsion with a Toll-like receptor (TLR) 4 agonist, induce protective CD4 T cell responses in animal models as well as providing therapeutic efficacy in canine leishmaniasis and in clinical trials in leishmaniasis patients.

Antibody Epitopes Identified in Critical Regions of Dengue Virus Nonstructural 1 Protein in Mouse Vaccination and Natural Human Infections.

Dengue is a global public health problem and is caused by four dengue virus (DENV) serotypes (DENV1-4). A major challenge in dengue vaccine development is that cross-reactive anti-DENV Abs can be protective or potentially increase disease via Ab-dependent enhancement. DENV nonstructural protein 1 (NS1) has long been considered a vaccine candidate as it avoids Ab-dependent enhancement.

Correction: Identification of Novel Pre-Erythrocytic Malaria Antigen Candidates for Combination Vaccines with Circumsporozoite Protein.

[This corrects the article DOI: 10.1371/journal.pone.

Identification of Novel Pre-Erythrocytic Malaria Antigen Candidates for Combination Vaccines with Circumsporozoite Protein.

Malaria vaccine development has been hampered by the limited availability of antigens identified through conventional discovery approaches, and improvements are needed to enhance the efficacy of the leading vaccine candidate RTS,S that targets the circumsporozoite protein (CSP) of the infective sporozoite. Here we report a transcriptome-based approach to identify novel pre-erythrocytic vaccine antigens that could potentially be used in combination with CSP. We hypothesized that stage-specific upregulated genes would enrich for protective vaccine targets, and used tiling microarray to identify P.