In an effort to make vaccines more available to people in difficult to reach areas, a team of scientists at McMaster University has developed an inexpensive, sugary gel that can preserve heat-fragile antiviral vaccines for over eight weeks at temperatures up to 40° C (104° F). The hope is that it will not only provide immunization to more people, but also aid in combating the spread of dangerous diseases like Ebola.
For over 200 years, vaccines have saved hundreds of millions of lives. They have turned many everyday diseases into rarities for much of the world, and smallpox into an endangered species. Today, they are our first line of defense against outbreaks of influenza and measles. Unfortunately, the modern antiviral vaccines we depend upon to prevent epidemics are restricted when it comes to distribution by what is called the "cold chain."
Many vaccines are very temperature sensitive and have to be kept at temperatures of between 2 and 8° C (37 and 46° F), which makes transporting them away from places where refrigeration is available very difficult. According to the McMasters team, shipping vaccines to some parts of Africa with things like solar-powered coolers that can be carried by camels make up 80 percent of the inoculation costs. Without that refrigeration, the vaccine can be made worthless in an hour.
The new technique reduces the need for refrigeration by taking standard vaccines and mixing them with the sugars pullulan and trehalose in a process that the team says is as simple as stirring cream and sugar into coffee.
It's a technology that was already developed by chemical engineers at McMaster and has been used for an edible coating to prolong shelf life for fruits and vegetables. The vaccine/sugar gel is stored in single-dose containers, where the gel dries out to form a seal. Later, clinicians mix the gel with water to recover the vaccine for use.
So far, the stabilized vaccines has been used with influenza and herpes simplex vaccines and have been tested on mice. Because the gel has already been approved by the US Food and Drug Administration, getting the technology to market may not take long and the team is working with a commercial partner to do just that.
"All the pieces are ready to go," says Carlos Filipe, chair of Chemical Engineering at McMaster. "It's actually quite simple compared to the technology required to create a vaccine itself."
The research was published in Scientific Reports and the video below discusses the technology.
Source: McMaster University