The vaccine technology is the brain child of the 37-year-old assistant professor of Mechanical and Biomedical Engineering at UCONN in the U.S.

Six years ago, Thanh began doing post-doctoral research at the Massachusetts Institute of Technology (MIT) where he and other members of a scientist group sponsored by Bill & Melinda Gates Foundation developed a vaccine technology that only requires single administration instead of multiple injections.

At the time, the team had successfully created microparticles for a single-injection vaccination. However, the particle size was larger than 0.2 mm, which was not small enough to reach the needle's top, hence limiting the the dose of vaccine transmitted into the body.

Not wanting his research efforts to go to waste, Thanh sought to create a new method that could overcome problems in his vaccine microparticles. In 2018, he came up with and coined the idea of making a vaccine patch similar to that used on a wound.

"Development of this patch has great implications for the universalization of global vaccines, especially people in remote areas who don't remember the repeat vaccination schedule, and where medical facilities are far away," Thanh said.

The vaccine patch developed by the group was created using an additive process called StampEd Assembly of Polymer Layers (SEAL) and computer chip manufacturing technology. This method helps create small, modulated particles that release the vaccine at different times and simulate the process of vaccine delivery into the body.

One patch is enough to produce the same immune effect as repeated injections over a long period of time, Thanh noted.

The size of a thumb, the patch is placed directly on the skin and allows the vaccine to enter the body through the epidermis without causing much pain like normal injections.

Because of its simple operation, it can be used at home to limit cross-contamination at high-risk health facilities.

The patch has an important component or microneedles made from dissolvable polymers. Since the needles are as small as hair strands, they cannot touch the body's nerves and do not cause pain. Once applied to the skin, the patch is removed to leave microneedles on the epidermis that deliver the vaccine to the body at various pre-programmed times.

Dr. Thanh Duc Nguyen. Photo courtesy of Thanh.

"The skin will heal itself and later cover these microneedles. After the vaccination is completed, the microneedles will dissolve and disappear from the skin."

The vaccine patch also increases the effectiveness of the drug because the skin has so many immune cells that react to the vaccine antigens, he said.

As such, the patch will both improve the quality of the vaccine and provide the full dosage in the most convenient way.

The team used a microneedle patch on mice with the Prevnar-13 vaccine, which fight pneumococcal bacteria that cause pneumonia, and published the results in biomedical journal Nature Biomedical Engineering early last year.

Thanh said it is still necessary to conduct human clinical trials to ensure the method is safe.

In addition to using microneedle patches for vaccines, his research group has also developed patches for anti-cancer immunotherapy or non-narcotic pain relievers and antibodies to treat different viruses.

The team also perfected automation to reduce production costs, making the products available to many users.