A group of scientists at McMaster University have discovered that mouthwash strips may lead to more than just fresh breath. With a grant from Grand Challenges Canada, they are developing an easy to distribute method for administering vaccines thanks to a specific polymer in the strip that preserves the vaccines at room temperature. The project is currently undergoing testing but, if successful, there could be huge implications in terms of radically lowering costs associated with the transportation and distribution of vaccines in the Global South.
The team of scientists, operating out of McMaster’s Biointerfaces Institute, are fusing live vaccines into a polymer used in the breath strips called pullalan. Sana Jahanshahi-Anbuhi, a chemical engineering PhD student at the University, is credited with making the discovery that the pullalan polymer stabilizes enzymes, preventing them from degrading at room temperature. It rests in a solid state but is easily dissolved in water, which is why the mouth strips melt in your mouth. The infused strips will be lightweight and can be transported and warehoused in large quantities all over the Global South. If successful, vaccine administration will no longer be complicated by unreliable power grids that refrigerator-equipped centres currently depend on. Given that the strips are water soluble, the vaccines will be reconstituted on site, on an as-needed basis.
The unique properties of the polymer were, upon initial discovery, utilized in a pill designed to test drinking water for pollutants like E-coli, pesticides, or metals. This is also convenient for use in the Global South where results may still have to be sent away. Even recent technology sometimes still depends on mobile devices or mobile labs or other more complicated or cumbersome equipment. The pill would give results instantaneously, proving to be a speedy, cheap and reliable field tool. While developing the pill, researchers found that they could use the strip to test for different kinds of contaminants. Upon realizing its ability to stabilize enzymes and other “fragile biologics,” the transition was made to incubating vaccines via the same properties.
Traditional vaccine administration often requires families to travel to wherever the inoculation is taking place. This could be at a local health centre in a village, but for many living in isolated rural areas, the trek to a health centre or mobile clinic can be arduous, dangerous, or wholly impossible. The high costs associated with transporting vaccines that need to be refrigerated, and for housing them in centres equipped with refrigerators has been a deterrent and a barrier to widening access to vaccines for many living in the Global South.
Grand Challenges Canada has committed $100,000 to the project, which is jointly led by Dr. Carlos Filipe, chair of the chemical engineering department at the University, and Dr. Ali Ashkar, who specializes in molecular medicine and pathology at McMaster’s Immunology Research Center. In order to mimic real-world conditions as closely as possible, a research team will store vaccine-loaded tabs at temperatures up to 40˚C. They will then be given to mice, which will be exposed to whichever infectious agent the vaccine corresponds to.
We will certainly be following up with this development as more information becomes available. For now, check out these articles about other alternative measures developed to store, transport, and administer vaccines.
Check out the video below of McMaster researchers discussing the potential of the pullalan water-testing pill.
 Which vaccines this development would be used for was not articulated