Vaccine in silicone
British doctors have created an "eternal" vaccine against tuberculosis
Biologists from the UK have developed a new type of "packaging" for the protein components of tuberculosis vaccines, which will allow them to be kept warm for almost unlimited time. This technology will make them cheaper and protect the world from a new epidemic, scientists write in the journal Scientific Reports (Wahid et al., Ensilication Improves the Thermal Stability of the Tuberculosis Antigen Ag85b and an Sbi-Ag85b Vaccine Conjugate).
"This will make it possible to transport vaccines around the world, especially to those parts of developing countries where infections occur most often. Today, half of the vaccines are thrown away, and cooling almost doubles their cost. The technology of "ensilication" will eliminate both of these problems," Assel Sartbayeva from the University of Bath said (in a press release Thermally-stable TB vaccine closer to reality thanks to microscopic silica cages – VM).
Tuberculosis remains, along with cancer and heart and vascular diseases, one of the main causes of death of people on Earth, especially in countries where HIV is widespread or there are unfavorable climatic conditions. The main and so far the only means to combat it is the BCG vaccine, developed by the French Albert Calmette and Camille Guerin back in 1921.
It is a weakened strain of bovine tuberculosis bacillus grown in special conditions and because of this has almost zero contagiousness to humans. Intradermal administration of the vaccine in childhood protects a person from Koch's bacillus for life, but the effectiveness of BCG remains a subject of debate among scientists. In addition, new versions of the microbe have now begun to spread across Eurasia, on which this vaccine no longer works.
In addition to the declining effectiveness, BCG has another disadvantage – an extremely short shelf life, which is why the "ready" vaccine needs to be stored in specialized refrigerators. This limits its use in developing countries. Therefore, the issue of creating a new tuberculosis vaccine capable of instilling immunity in both children and adults is one of the main priorities for doctors and scientists today.
Prototypes of such alternative vaccines already exist – one of them was recently created in South Africa, and others – at the Gamalei Russian Center for Epidemiology and Microbiology and the Hopkirk Institute in New Zealand. Now they are undergoing clinical trials and their practical application will not begin soon.
Sartbayeva and her colleagues at the university have created a technology that will significantly reduce the cost of BCG or new vaccines, and also make them virtually "eternal" by experimenting with various complex silicon compounds and organic substances.
Recently, as the chemist notes, her team found out that certain types of organosilicon polymers can combine with protein molecules and stabilize them even in the absence of water and at "wrong" temperatures.
This discovery prompted scientists to think that BCG and other tuberculosis vaccines, whose protein components become unstable at room temperature, can be "packaged" in a similar way. For such experiments, scientists have chosen the New Zealand Ag85a vaccine, the first and so far the most promising drug of its kind.
Having prepared the usual version of this drug and its "packaged" version, biologists monitored how proteins would behave during prolonged storage outside the walls of the refrigerator.
As these experiments showed, the unprotected vaccine deteriorated in just four days, while the silicone packaging made it extremely resistant to heat and other destructive actions. It remained almost in pristine condition throughout the entire week of experiments and did not collapse, even if scientists heated the "sealed" vaccine several times.
Similarly, as noted by Sartbayeva and her team, other types of vaccines can be stabilized. This will simplify and reduce the cost of fighting not only tuberculosis, but also other infections that are now widespread in Asia and Africa, scientists conclude.
Portal "Eternal youth" http://vechnayamolodost.ru