Scientists Discover a Way to Preserve Vaccinations Without Refrigeration
Ever since the invention of the first vaccines in the 18th century, they have saved the lives of millions of people. In the 220 years since the first smallpox vaccine, the disease has been fully eradicated and other infectious diseases are not that far behind – at least in developed countries.
Now, a team of Canadian scientists from McMaster University in Hamilton, Ontario, have developed what could be a simple and inexpensive way to preserve vaccines without refrigeration; vaccines must be stored between 2 degrees and 8 degrees Celcius. This could be a potential game-changer in remote and impoverished places where cold storage is simply not possible.
The new method combines the active ingredients of existing vaccinations with a sugary gel that will allow it to remain viable at higher temperatures, according to a McMaster University news release. The result is a very light, durable, and compact dose that only adds a tiny amount to the manufacturing cost but ultimately saves money in transportation.
The idea for the research came from a eureka moment when one of the paper’s authors, Sana Jahanshahi-Anbuhi, came across Listerine strips in a grocery store while she was a graduate student at Concordia University. Jahanshahi-Anbuhi looked at the thin sheets of film that are made of a pullulan (a sugar) and thought that the Listerine ingredients could be swapped out for something else like a protein or virus from a vaccine.
It turns out that they could. The research team led by professor Carlos Filipe combined herpes and influenza A vaccines – two of the most heat-sensitive vaccines – with a sugar solution and dried the mixture into a thin film.
“Combining the vaccines and the sugars – pullulan and trehalose – is almost as simple as stirring cream and sugar into coffee,” the researchers said. The pullulan creates a barrier around the vaccine to keep oxygen out, and the trehalose helped protect the vaccine from drying out when it was dried into a film – this technology has already been used in other applications.
They stored the dried vaccines at a scorching 40 degrees Celsius (104 F), reconstituted it in saline and tested it in mice. The vaccines were safe and as effective as they would have been out of cold storage, according to Filipe, who is the chair of chemical engineering at McMaster. The herpes vaccine was good for two months, and the flu vaccine for three.
This discovery solves the cold chain storage problem for getting vaccines into remote, undeveloped parts of the world.
So far, vaccines have been delivered by camels carrying solar-powered mini-refrigerators and by drones, but there are still areas of the world that never get vaccines. That makes it impossible to fully eradicate diseases and keep epidemics in check.
“If you can’t get vaccines to the places where people need them, there’s no point in having them,” said co-author Matthew Miller, an assistant professor in the Department of Biochemistry and Biomedical Sciences in the University release.
The research team collaborated with health sciences colleagues who specialized in virology and immunology, and the results were published in the May 21, 2019, issue of Scientific Reports. “Often, complex problems have simple solutions. It just takes the right team,” said Miller. “The best research comes from merging fields, when you do something with someone else that you couldn’t do alone.”
The next step will be to test more vaccines and to do human trials. The US Food and Drug Administration already approve the materials used in the storage medium, so that will make it easier to go forward. The team just applied to the Gates Foundation for funding.
“All the pieces are ready to go,” said Filipe. “It’s actually quite simple compared to the technology required to create a vaccine itself.”
Expediting this new method of vaccine storage through human trials and to market will go a long way in putting a stop to preventable diseases and saving the lives of millions of people around the planet.
