Leishmaniasis is a neglected tropical disease caused by parasites of the genus Leishmania. As approved human vaccines are not available, treatment and prevention rely heavily on toxic chemotherapeutic agents, which face increasing resistance problems. The development of effective vaccines against human leishmaniasis is of utmost importance for the control of the disease. Strategies that have been considered for this purpose range from whole-killed and attenuated parasites to recombinant proteins and DNA vaccines. The ideal vaccine must be safe and effective, ensuring lasting immunity through a robust IL-12-driven Th1 adaptive immune response. Despite some success and years of effort, human vaccine trials have encountered difficulties in conferring durable protection against Leishmania, a problem that may be attributed to the parasite’s antigenic diversity and the intricate nature of the host’s immune response. The aim of this review is to provide a thorough overview of recent advances in Leishmania vaccine development, ranging from initial trials to recent achievements, such as the ChAd63-KH DNA vaccine, which underscores the potential for effective control of leishmaniasis through continued research in this field.

The SARS-CoV-2 virus is an emergent, zoonotic pathogen that has caused a huge burden of disease and mortality around the world since its emergence in 2019. Safe and accessible platforms to evaluate viral entry and potential antiviral compounds remain essential for ongoing drug discovery against emerging variants. This article describes a highly optimized protocol for generating murine leukemia virus (MLV)-based pseudotyped particles expressing the SARS-CoV-2 spike protein and carrying a luciferase reporter gene, enabling the study of viral entry under biosafety level 2 conditions. The methods described detail the use of optimized cell lines, high transfection efficiency using cost-effective reagents, production of highly effective pseudoviruses, and titration of infectivity to determine the minimum viral input for screening assays. Representative results demonstrate robust luciferase activity in infected cells compared to non-infected controls, while control spike-less and VSV-G-pseudoviruses confirm assay specificity. Furthermore, the system supports compound screening by quantifying inhibitory effects on viral entry and assessing cytotoxicity using an MTT viability assay. Overall, this reproducible and scalable protocol provides a reliable platform for medium to high-throughput screening of novel viral entry inhibitors, contributing to the identification of antiviral candidates and advancing research on SARS-CoV-2 entry mechanisms.

The SARS-CoV-2 virus is an emergent, zoonotic pathogen that has caused a huge burden of disease and mortality around the world since its emergence in 2019. Safe and accessible platforms to evaluate viral entry and potential antiviral compounds remain essential for ongoing drug discovery against emerging variants. This article describes a highly optimized protocol for generating murine leukemia virus (MLV)-based pseudotyped particles expressing the SARS-CoV-2 spike protein and carrying a luciferase reporter gene, enabling the study of viral entry under biosafety level 2 conditions. The methods described detail the use of optimized cell lines, high transfection efficiency using cost-effective reagents, production of highly effective pseudoviruses, and titration of infectivity to determine the minimum viral input for screening assays. Representative results demonstrate robust luciferase activity in infected cells compared to non-infected controls, while control spike-less and VSV-G-pseudoviruses confirm assay specificity. Furthermore, the system supports compound screening by quantifying inhibitory effects on viral entry and assessing cytotoxicity using an MTT viability assay. Overall, this reproducible and scalable protocol provides a reliable platform for medium to high-throughput screening of novel viral entry inhibitors, contributing to the identification of antiviral candidates and advancing research on SARS-CoV-2 entry mechanisms.