While scientists are diligently advancing a Zika virus vaccine towards human trials, another team of researchers is focused on preventing the spread of a different insect-borne disease called Leishmaniasis. Their objective is to develop a vaccine to combat this disease in the Americas.
A collaborative effort involving researchers from Japan, Brazil, Canada, and the United States has employed cutting-edge gene editing technology called CRISPR-Cas9 to modify the DNA of the Leishmaniasis parasite. By doing so, they aim to create a live-attenuated vaccine, which, once approved, would be the first of its kind to target a parasitic infection.
Neglected tropical diseases, as exemplified by previous outbreaks such as Ebola and Zika, have the potential to swiftly become significant global health threats. Recognizing this, the development of a vaccine against Leishmaniasis, which has been in progress for over two decades, holds immense promise in preventing the onset of Leishmania infections.
The primary manifestation of this parasitic protozoan infection is disfigured skin, but the parasites can also lurk silently in the bloodstream, hide within immune cells, and establish themselves firmly in the spleen, liver, and bone marrow, leading to potentially fatal consequences.
Due to the current treatments being expensive and associated with toxic side effects, an estimated 50,000 out of 2,000,000 infected individuals succumb to the disease each year. Controlling Leishmaniasis is particularly challenging in resource-limited communities, and the parasite has also shown signs of developing resistance to existing therapies.
Leishmaniasis has a high incidence in Asia, the Middle East, and Central and South America, including regions along the southern US border and Puerto Rico. Public health experts have also observed isolated outbreaks in dog kennels across the United States, as the parasite can easily be transmitted from animals to humans.
The concept of developing a vaccine for Leishmaniasis is not entirely new, as a process called Leishmanization was previously practiced in certain rural communities. However, the current vaccine being developed is designed to effectively combat natural infection through sand fly bites and is not limited to animal models.
To ensure the production of a live-attenuated vaccine that meets FDA standards, the research team is collaborating with an Indian manufacturer. India bears approximately 80% of the global burden of Leishmaniasis.
The global research team comprises Shinjiro Hamano, PhD, from the Institute of Tropical Medicine at Nagasaki University; Greg Matlashewski, PhD, from McGill University in Montreal; Jesus Valenzuela, PhD, from the National Institute of Allergy and Infectious Diseases, National Institutes of Health; Abhay Satoskar, MD, PhD, a microbiologist at The Ohio State University Wexner Medical Center and Center for Microbial Interface Biology; and Hira Nakhasi, PhD, a researcher with the US Food & Drug Administration (FDA).
