Non-human primate depletion models for the study of Lassa virus pathogenesis and correlates of protection associated with Lassa fever vaccines.

Lassa virus is a prominent cause of severe hemorrhagic disease in humans, referred to as Lassa fever, primarily in West African countries. In nature, Lassa virus uses a common rodent species as its natural reservoir and is transmitted directly from infected rodent to human, though human-to-human transmission also occurs. It is estimated that greater than 300,000 people are infected each year with Lassa virus resulting in significant illness and death across this region of Africa. Despite this, no vaccine is currently approved for use to prevent illness in humans. The methods utilized by Lassa virus to cause disease are largely unknown, though it is thought that excessive immune responses in humans plays a vital role in the severity of disease. To explore this, we seek to impair certain cell types responsible for defined immune responses in an animal model of Lassa Fever to clarify their roles in disease progression and severity. A better understanding of both beneficial as well as harmful immune responses will aid scientists in developing targeted medicines to treat Lassa Fever in humans. Expanding on these findings and using a similar immune dampening approach, we then aim to demonstrate that immunization with a leading made-in-Canada Lassa Fever vaccine results in protection from LASV infection through the generation of a potent antibody response.