The USC researchers have developed an injectable polio vaccine that does not require preservation at low temperature facilitating its safe transportation to remote areas.
The study which appeared in the journal mBio reports that the injectable vaccine, which was freeze-dried into a powder, kept at room temperature for four weeks and then rehydrated, offered full protection against the polio virus when tested in mice.
A majority of human vaccines are temperature sensitive. The dependence of current vaccines on the cold chain, which prevents exposure to ambient temperature and also to freezing, presents many obstacles that can lead to failure of vaccination campaigns.
“Stabilization is not rocket science, so most academics don’t pay much attention to this field,” said the study’s first author, Woo-Jin Shin, Ph.D.,
“However, no matter how wonderful a drug or vaccine is, if it isn’t stable enough to be transported, it doesn’t do anyone much good,” he added.
Polio is on the verge of complete eradication but few cases of polio have been noted in countries like Nigeria, Papua New Guinea, Syria, and Pakistan. The biggest obstacle to complete eradication is creating a temperature-stable vaccine for use in developing countries where refrigeration may be unavailable.
The good news knocking the door is that by removing moisture through freeze-drying, researchers have created temperature-stable vaccines for measles, typhoid, and meningococcal disease. But scientists haven’t been able to make a polio vaccine effective in human that retains potency through freeze-drying and rehydration, though it has been successfully tested in mice.
Shin and his colleagues used two lab techniques – liquid chromatography and high-throughput screening – that allowed them to analyze a high volume of ingredients and formulations until they found one that worked.
“This study shows the establishment and optimization of lyophilization conditions to increase the in vitro and in vivo thermostability and vaccine capacity of sIPV at temperatures up to 40°C for at least one month, “write the authors.
The researchers believe that a foundation or company will take over the project to pay for human studies and bring the injectable vaccine onto the market.
For full information log on to 10.1128/mBio.02287-18