Stanford Researchers Develop Skin-Based Vaccine Using Harmless Bacteria
TEHRAN (Tasnim) – Stanford University researchers have engineered a topical, needle-free vaccine using a harmless skin bacterium that could replace traditional injections, offering a pain-free alternative without inflammation or side effects.
Stanford scientists have created a groundbreaking method of delivering vaccines by turning a common skin bacterium, Staphylococcus epidermidis, into a living vaccine that can be applied as a cream.
The research, published in Nature on December 11, was led by bioengineering professor Michael Fischbach and postdoctoral scholar Djenet Bousbaine.
Fischbach explained the appeal of a needle-free alternative: “We all hate needles — everybody does. I haven’t found a single person who doesn’t like the idea that it’s possible to replace a shot with a cream.”
The bacterium, which naturally resides on human skin, triggered a robust immune response in both mice and human studies. “It’s as if the mice had been vaccinated,” Fischbach said.
In their experiments, researchers swabbed mice with S. epidermidis, prompting the production of high antibody levels. The team identified a protein, Aap, as the key trigger for this immune response.
Fischbach’s team bioengineered S. epidermidis to display harmless fragments of tetanus and diphtheria toxins within Aap’s structure. The modified bacteria successfully induced strong antibody production in mice, protecting them from lethal toxin doses.
The approach also produced antibodies targeting mucosal surfaces in the nostrils, which Fischbach noted could help stop respiratory pathogens like flu and COVID-19 before they infect the body.
“Normal vaccines go to work only once the pathogen gets into the blood,” Fischbach said. “It would be much better to stop it from getting in the first place.”
The team further tested a chemically modified version of the bacteria, enhancing its ability to generate protective antibodies. Fischbach said their next steps include trials on monkeys, with human clinical trials anticipated in two to three years.
“We think this will work for viruses, bacteria, fungi, and one-celled parasites,” Fischbach said. “We expect that you wouldn’t experience any inflammation at all.”
The research was supported by collaborations with the University of California, Davis, and several US National Institutes of Health agencies.