Nanoparticle vaccines are designed to effectively deliver a lower dose with fewer side effects for at-risk people.
Cleveland Clinic researchers have used nanoparticles to develop a potential vaccine candidate against Dabie Bandavirus, formerly known as Severe Fever with Thrombocytopenia Syndrome Virus (SFTSV), a tick-borne virus that currently has no prevention, treatment or cure.
The patent-pending vaccine uses nanoparticles to carry the antigens that contain instructions for fighting off a virus. Nanoparticle vaccines are designed to effectively deliver antigens at a lower dose with fewer side effects for at-risk groups – including adults over age 50, who are the most vulnerable to SFTSV and the most susceptible to vaccine side effects.
The research, published in mBio, was led by Jae Jung, PhD, Director of Cleveland Clinic’s Sheikha Fatima bint Mubarak Global Center for Pathogen & Human Health Research. “The Pathogen Center was founded to prepare for and protect against future global health crises before they start,” says Dr. Jung, who also serves as Department Chair of Cancer Biology and Director of Infection Biology. “There is already a desperate need for a SFTSV vaccine in Asia. Our goal was to develop one before it’s needed in America, too.”
The World Health Organization had declared SFTSV as needing “urgent research attention” several years ago, and it is still listed as a threat by the National Institutes of Health in the U.S. The virus spreads through the Asian longhorn tick, a species already present in 19 U.S. states, including Ohio. It can also sometimes spread from human to human, mainly in a hospital setting.
Currently, physicians can only address the virus’s symptoms and keep infected patients hydrated and comfortable. While many people experience mild symptoms, adults over 50 years old can become severely ill and face a 30% mortality rate.
This same population unfortunately experiences certain vaccine side effects that typically don’t affect younger people.
“We become more sensitive to certain vaccine side effects the older we get,” says study first author Dokyun (Leo) Kim, a graduate student in the Jung lab. “We wanted to develop a treatment that’s age-dependent and can be given safely to the people who need it the most.”
Nanoparticle vaccines are promising for treating these at-risk groups because the antigens are bundled together, instead of free-floating throughout our bodies. Because our immune cells can find bundles of antigens on a nanoparticle more easily, the vaccine can be effective using a lower dose. When the vaccine dosage is reduced, its potential side effects are reduced as well, according to preliminary research conducted by Kim.
The Jung Lab hopes to test the SFTSV vaccine in humans, next. Kim says the possibilities don’t end there.
“We’re working to apply our nanoparticle technology to other viruses,” he says. “We have already developed a candidate for SARS-CoV-2, and we’re not stopping anytime soon.”
The funds, the first to go to Cleveland Clinic’s new Center for Global and Emerging Pathogens, will support Dr. Jung’s work to test four vaccine candidates against the virus that causes severe fever with thrombocytopenia.
Putting forth multiple candidates with different side effects and dosing schedules aims to provide more options for preventing public health threats.
Dr. Jae Jung will study the natural course of infection and viral reassortment of the emerging pathogen, Severe Fever with Thrombocytopenia Syndrome Virus (SFTSV).