A new study assisted by researchers from the University of Melbourne has shown that a single dose of an experimental vaccine, administered in mouse models, turbo-charged immune cells, providing rapid protection against eight different bacteria and fungi species, including MRSA.
The team, predominantly from USC, designed the formula to prevent serious infections from drug-resistant pathogens in the hope that a vaccine, given to patients just before or after arriving at the hospital, could protect them against lethal superbugs that lurk in healthcare settings.
The study was published 4 October in Science Translational Medicine, and the USC Stevens Centre for Innovation, the technology licensing office for the university, has already successfully filed one patent for the vaccine and is pursuing others, under the banner of the developers’ startup ExBaq LLC.
Co-author, Dr Brad Spellberg, CMO at the USC-affiliated Los Angeles General Medical Centre noted that in many cases, infections were caused by so-called superbugs, such as methicillin-resistant Staphylococcus aureus (MRSA) or Acinetobacter baumannii.
“The infections spread via contaminated surfaces or equipment, such as catheters or ventilators, or though person-to-person spread, often from contaminated hands, and the risk is highest among ICU patients who may suffer surgical site infections, bloodstream infections, urinary tract infections and ventilator-associated pneumonia” he said.
“Typical vaccines usually prompt the body to make antibodies against a specific pathogen, yet despite the high incidence of healthcare-acquired infections, there are currently no FDA-approved vaccines that prevent the most serious, antibiotic-resistant infections.
“Even if there were such vaccines, multiple vaccines would have to be deployed simultaneously to protect against the full slate of antibiotic-resistant microbes that cause healthcare-acquired infections.”
The experimental ExBaq vaccine takes an entirely different approach, by hyperactivating the macrophages which engulf and digest bacteria, fungi, and other pathogens.
PhD student at Keck School of Medicine of USC and the study’s lead author, Mr Jun Yan, explained that the approach of using the body’s own immune system to tackle superbugs was “very different from developing new antibiotics.”
“The vaccine is comprised of just three ingredients, two of which are already used in FDA-approved vaccines, and a third component is a tiny piece from the surface of a fungus commonly found on human skin,” he said.
Tested in two independent labs, the vaccine worked within 24 hours and lasted for up to 28 days. In lab models, the number of pathogen-eating immune cells in the blood increased dramatically, and survival time of invasive blood and lung infections improved. Early data suggest that a second dose could extend the window to prevent infection.
ExBaq’s founders have begun talking with potential pharmaceutical partners who might be interested in further developing the vaccine for human clinical trials.
“The next step is getting guidance from the FDA on the requirements to complete preclinical studies and submit and Investigational New Drug Application (IND) in 2024,” Dr Spellberg said.
“The first such trial would be done in healthy volunteers to find the right dose of vaccine that is safe and triggers the same kind of immune response in people as seen in the mice.”