Stanford Researchers Develop First-Ever Topical Vaccine Using Skin Bacteria

Stanford University scientists have engineered a groundbreaking topical vaccine using the common skin bacterium Staphylococcus epidermidis. This promising innovation could replace traditional needle-based vaccinations with a painless cream, making immunization more accessible and less daunting.

Imagine a vaccine that you could simply rub onto your skin rather than enduring the discomfort of a needle. This groundbreaking prospect is closer to reality thanks to the innovative work of researchers at Stanford University.

Michael Fischbach, the Liu (Liao) Family Professor and a professor of bioengineering at Stanford, and his team have domesticated Staphylococcus epidermidis, a common skin bacterium, transforming it into a workable, pain-free vaccine.

“We all hate needles — everybody does,” Fischbach said in a news release. “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 human skin may not seem like an ideal environment for living organisms due to its dryness and salinity, but Staphylococcus epidermidis thrives there.

“These bugs reside on every hair follicle of virtually every person on the planet,” Fischbach added.

Driven by a curiosity about the skin’s ecosystem, Fischbach and postdoctoral scholar Djenet Bousbaine, a senior and lead author of the study, explored whether the immune system of mice would produce antibodies in response to S. epidermidis.

Their experiments revealed that the immune system does indeed mount a robust antibody response to the bacterium.

“It’s as if the mice had been vaccinated,” Fischbach added, noting the immune response was comparable to that of traditional vaccinations.

Furthermore, similar high levels of antibodies were found in humans, suggesting a preemptive immune defense mechanism against skin colonizers.

The breakthrough came when the team engineered S. epidermidis to include a protein that triggers an immune response. This protein, known as Aap, was equipped with elements from toxins like tetanus, to observe if it could invoke a specific antibody response.

“Djenet did some clever engineering,” Fischbach said, highlighting Bousbaine’s efforts.

Their approach proved effective: mice treated with the engineered S. epidermidis developed strong antibodies against these toxins. This protected them from lethal doses, showcasing the potential of this novel vaccination method.

The implications are profound. This topical vaccine could potentially be adapted for protection against various pathogens, including viruses and fungi.

“We think this will work for viruses, bacteria, fungi and one-celled parasites,” Fischbach said, adding that this method could omit the inflammatory responses typical of current vaccines.

The research, published in the journal Nature, could lead to clinical trials within two to three years, according to Fischbach.