25 February 2021

Translating a DNA-Based Vaccine to Prevent Lethal Lassa Fever Infection

Researcher to Watch: Kathleen A. Cashman, PhD

Kathleen Cashman, PhD is a Geneva principal investigator and employee working on-site at the Virology Division of the United States Army Medical Research Institute of Infectious Diseases (USAMRIID). In the dogged pursuit of a vaccine to provide protection against Lassa virus and the hopeful culmination of 15 years of research, Dr. Cashman is working, in collaboration with Inovio Pharmaceuticals, to translate the DNA-based vaccine candidate INO-4500 into, eventually, an FDA-approved vaccine.

Lassa fever, an acute viral illness spread by infected rats, occurs most frequently in West Africa where over 300,000 people are infected annually. A lesser-known virus here in the United States, this virus causes large, recurrent outbreaks with high case fatality rates and side effects with terrible impacts on the lives of the survivors, such as complete deafness in communities where a lack of hearing can have a tremendous negative impact. One of the most recent and devastating impacts was seen in Nigeria, where in addition to the havoc caused by the COVID-19 pandemic, Nigeria is also currently facing an ongoing outbreak of Lassa virus. Over 960 cases were reported in Nigeria from January 1, 2020 to April 5, 2020. With no licensed vaccine or approved treatment for Lassa fever, Dr. Cashman’s work faces an urgent need head-on.

In May 2019, Inovio issued a press release announcing the first dosing of human subjects in clinical trials to evaluate the efficacy of INO-4500, bringing military medicine one step closer to the prevention of infection from the Lassa virus. The press release states the company has received Phase 2 funding in the amount of $52 million from the Coalition for Epidemic Preparedness Innovations (CEPI) for further development and plans for emergency use as a stockpiled vaccine.

This announcement was preceded by research published by Dr. Cashman and co-authors in the October 2017 issue of Human Vaccines & Immunotherapeutics titled “A DNA vaccine delivered by dermal electroporation fully protects cynomolgus macaques against Lassa fever”, demonstrating the vaccine’s ability to provide 100% protection in non-human primates when challenged with a lethal dose of the virus.

Dr. Cashman’s work is well-funded, including a $3.5 million grant from the National Institute of Allergy and Infectious Diseases (NIAID) for her Lassa virus research.

“I started working on this vaccine project right out of graduate school and was fortunate to have good success early on. I have often referred to it as ‘The Little Vaccine That Could’ because it took some perseverance to keep it moving forward in a difficult funding environment,” said Dr. Cashman. “It’s a dream come true to have the opportunity to bring a product from concept to human use approval.”

Lassa fever is a horrible disease that is fatal for many but also leaves survivors with devastating lasting effects. Dr. Cashman added, “It is the honor of a lifetime to have the opportunity to develop a product to protect our troops from this disease, but also to potentially improve the overall public health in the endemic region.”


Disclaimer: The views expressed do not reflect the official policy of the Army, the Department of Defense, or the U.S. Government.

Researcher to Watch- Cashman