A total of 22 people were infected with polio in 2017. It is the whisper of the liquidation, but due to problems associated with the production of vaccines, where it is most needed, the disappearance of the polio virus in the wild remains out of reach.
End may finally be in sight, thanks to a new method for preserving the vast inactivated form of the vaccine – this new method does not require refrigeration.
As a lyophilized powder, the vaccine can now be sent to areas previously off limits to provide much-needed immunity to a handful of groups, which are still at risk from this devastating disease.
Scientists from the University of Southern California, worked with researchers from the drug manufacturer Integrity Bio to develop a process that removes moisture from the inactivated poliovirus vaccine (IPVS), without prejudice to their effectiveness, to enhance their stability at ambient temperature.
"However, no matter how wonderful the drug or vaccine, if it is not stable enough to be transported, it does not do anyone much good," says the study's first author, Woo-Jin Shin.
There are two kinds of polio vaccine. It was first developed as a known Jonas Salk in 1950, and includes John & # 39; ektsyyu broken particles to the poliovirus.
The second method was developed in the next decade, Russian-born medical researcher Albert Sabin. Although it requires no needles, it is easy to delivery of oral vaccines based on a live, weakened form of the virus, so carries some risk of contracting the disease.
This risk is not exactly huge. Only 96 cases of polio vaccine origin occurred in 2017, and the chances of those with the virus, suffering from its debilitating symptoms are also very small.
Nevertheless, it is a risk that we could do. Therefore, the Global Polio Eradication Initiative is phasing out its use in general, and sticking to the injected vaccine.
Using IP in certainly a safe bet, but, like most biological materials, light, temperature and other environmental conditions to finish its proteins, rendering it useless when it comes to the inoculation against the disease.
If kept at a cool 2 to 8 degrees Celsius (35 to 46 Fahrenheit) bottle and can be stored for up to four years. Otherwise, they go away, like a fish on a summer day.
Freeze drying of vaccine ingredients can help stretch their used by date significantly, the method is already being used to ship vaccines against measles, typhoid and meningococcal disease in remote corners of the globe.
However, dehydration and proved to be more difficult, resulting in less than impressive stability at ambient temperatures.
Search the new process is not all that difficult. At least not in principle.
"Stabilization of the Sun rocket science, so most scientists do not pay much attention to this field," says Shin.
It is difficult to know what methods to & # 39 are winners, and that turn a potentially life-saving vaccine ineffective dust pile.
Thus, the start command through the development of new in vitro assay for determining the potency and after its preparation.
They then went on sifting through a variety of compositions for freeze-drying using high performance liquid chromatography, to quickly sort out which ones will continue to work their magic.
The result was IPV, which could be stored at temperatures up to 37 degrees Celsius (99 degrees Fahrenheit) for four weeks, and be as effective as non freeze-dried vaccines, which were kept in cold 4 degrees Celsius (39 degrees Fahrenheit ).
Tested in mice, then rehydrated form of the vaccine still provided the same level of immunity.
Polio is a & # 39 is a disease that most of us could be forgiven for thinking already extinct. Such cases were not registered in the United States since 1979.
For immunization, the annual cases may be nearly 60,000 during outbreaks. Among adults with paralytic form of the disease, up to nearly a third have faced death.
There are three strains of polio virus. One of them was officially declared eliminated in 2015, nearly 16 years after the last of this kind has been found in India. We have not seen since 2012.
But that still leaves one variety persists in the communities in Pakistan and Afghanistan. If we really see the end, and to avoid a return to this epidemic, we have to overcome all obstacles.
The world needs this vaccine, to finish the job.
The study was published in mBio.