McMaster University researchers have come up with a method for storing fragile vaccines, at temperatures up to 40 degrees Celsius, paving the way for life-saving anti-viral vaccines to reach remote and impoverished regions around the world.
Their method combines the active ingredients in existing vaccines with a sugary gel (including pullulan and trehalose), enabling them to remain viable for up to eight weeks, even at high temperatures.
The light, durable, and compact doses are ideal for shipping Ebola vaccine, for example, to affected areas of Africa, the researchers say. Also, the process involves only minimal additional costs in preparing a vaccine, and virtually eliminates the entire cost of transporting it, which can account for 80% of the total cost of inoculation.
Combining the vaccines and sugars is comparable to adding cream and sugar to coffee, according to the researchers. The storage technology was created by chemical engineers at McMaster, who had already demonstrated its effectiveness in other applications, such as edible coatings that prolong the shelf life of fruits and vegetables.
The invention is significant as it can replace the current “cold chain”––(constant storage between 2–8° C)––a burdensome method that is necessary to safeguard the viability of anti-viral vaccines. Maintaining the cold chain presents a challenge for inoculating people in remote or poor areas of the world, where the necessary infrastructure may not be available.
The challenge is so great, the researchers say, that in some regions, vaccines are transported by camels equipped with solar-powered mini-refrigerators. Some populations simply never receive vaccines, and being unable to get vaccines to isolated areas makes eradicating deadly viruses impossible.
The new vaccine-storage method suspends the vaccine’s active components in a tiny container with a sugar gel that dries to seal in the vaccine. Later, clinicians reconstitute the vaccine with water and administer it to patients in the usual manner.
To prove the method’s viability, the researchers used influenza virus and herpes simplex virus to inoculate and test mice by exposing them to the viruses, as their immune response is similar to that of humans.
The materials in the storage medium material are already FDA-approved and the researchers are now working with a commercial partner to bring their technology to market.
Source: McMaster University, May 21, 2019
Source: FDA, May 16, 2019