Freeze-dried polio vaccine could help save lives in remote areas

The polio vaccine can successfully prevent the deadly crippling disease caused in children. The currently available vaccine is in liquid form and is also heat labile.

This means that when it is exposed to a temperature above the recommended temperature at any moment of its transit, the vaccine loses its effectiveness even when it is cooled down again.

Researchers have developed a freeze-dried form of this vaccine that can be stored as a dried powder at room temperature.

Computer model of the human poliovirus. The poliovirus infects children and causes poliomyelitis, a disease that in severe cases damages the nervous system, causing paralysis or death. Image credit: vitstudio / Shutterstock

This could help eradicate the disease, say the researchers. The results of their study on the new version of the vaccine titled "Development of a freeze-dried and heat-stable Sabin inactivated poliovirus vaccine" were published in the latest issue of the journal mbio.

The polio virus is highly contagious and spreads to children in densely populated and isolated areas where the vaccine currently used is unable to reach. This includes the regions of Nigeria and Pakistan that could benefit from the vaccine and help them eradicate the infection that could lead to lifelong paralysis or even death.

The oral vaccine currently used uses a weakened form of the live polio virus. This weakened virus can help vaccinated children develop immunity against infection. There is another form of vaccine – injectable polio vaccine – IPV. It contains dead virus strains and can be stored at temperatures below about 4 ° C (39.2 ° F).

This new vaccine is the lyophilized form of IPV. This new version of IPV can be stored at higher temperatures, up to 40 ° C for four weeks. The vaccine can then be reconstituted for use. The drug retains its power.

Woo-Jin Shin, co-author of the Southern University of California report, said in a statement: "We have lyophilized the inactivated polio vaccine and, during freeze-drying, we added ingredients that make it more stable."

The team of researchers at Southern University of California, supported by a company called Integrity Bio Inc., created this new formulation of magnesium sulfate, histidine, amino acids and mannitol sugar which stabilized the preparation.

The vaccine has been stored at different temperatures. It was then reconstituted and administered to mice. The researchers wrote that the vaccine was still potent after four weeks of exposure to high temperatures. This would mean that charitable foundations working in remote areas where it is difficult to maintain a cold transit could help people write better to researchers.

"No matter how good a drug or vaccine is, if it's not stable enough to be transported, it will not do anybody any good," said Dr. Shin. The polio virus can be transmitted from person to person through direct contact, food and contaminated water. The infection itself may be mild or non-symptomatic, but about 0.5% of cases can cause paralytic disease that can lead to disability for life, the researchers write.