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- Parasitic feature: the Gamalea center is ready to create a vaccine against infection of "mutant ticks"
Parasitic feature: the Gamalea center is ready to create a vaccine against infection of "mutant ticks"
It will take months to create a vaccine against Congo-Crimean hemorrhagic fever, the N.F. Gamaleya Center told Izvestia. There is currently no specific treatment for this deadly infection. The spread of "mutant ticks" carrying this disease is recorded in the southern regions of Russia. Their habitat is gradually shifting to the north against the background of global warming. According to experts, individual parasites can also enter the capital region with the help of migratory birds, and the further spread of infection largely depends on weather conditions and how hot the summer season will be. According to virologists, the development of a vaccine is necessary primarily to protect medical workers who may come into contact with infected patients.
Congo-Crimean fever vaccine
A vaccine against Congo-Crimean hemorrhagic fever, spread by ticks of the Hyalomma genus, which the media called "mutant ticks," can be created within months, Alexander Ginzburg, scientific director of the Gamaleya National Research Center for Epidemiology and Microbiology, told Izvestia.
— We do not have an order for the development of such a vaccine yet. Congo-Crimean hemorrhagic fever was previously found in the southern regions, but there is a tendency for the ticks that carry it to adapt to low temperatures and expand their range. There is no specific treatment for this disease. To create a vaccine, you can use one of the proven platforms that have previously been used against other pathogens. If an appropriate decision is made and funding is allocated, this work will take months," the scientist said.
Reports of the spread of "mutant ticks" in the southern regions of the Russian Federation, where they had previously been rare, began to appear on March 18. So, they were seen on the territory of the Volgograd, Rostov and Astrakhan regions. Later, Mikhail Alekseev, a leading researcher at the disinsection department of the Institute of Disinfection at the Erisman Federal Research Center for Hygiene at Rospotrebnadzor, explained that this species had been living in the south of the Russian Federation for a long time and was unlikely to be able to reach the Moscow Region, as it was "too humid and uncomfortable for them."
Hyalomma is a genus of blood—sucking mites common in Africa and southern Eurasia. Unlike forest ticks, which they noticeably outnumber, Hyalomma do not just wait for their prey, but are able to chase it by heat and smell. They have a dark brown or black body with striped paws.
According to biologist Dmitry Safonov, due to the unprecedented snowy winter, the soils in the central part of Russia have frozen shallowly. Thanks to this, many insects and ticks have successfully endured the cold, and there will be especially many of them this season.
Hyalomma ticks mainly inhabit open steppe landscapes: pastures, meadows and steppes. Here they can find and actively pursue their prey by scent. For example, horses or cows. There is a high probability of bites for agricultural workers in grazing. But you won't find this species in forests or parks with dense vegetation. A tick can enter Moscow or the region randomly with insectivorous birds, including swifts and swallows. However, he will not be able to settle down here, as the climate is too cold for him," said Dmitry Safonov.
Migration of ticks
Ticks of the Hyalomma genus are the main carriers of the Congo—Crimean hemorrhagic fever virus, which can be transmitted both between the parasites themselves and through their eggs, so the spread of parasites must be controlled, said immunologist Mikhail Bolkov.
— With the development of the disease, the virus affects the walls of blood vessels and immune cells. The inflammation is accompanied by high fever with a specific two-wave fever, as well as hemorrhages. Some patients recover, but mortality varies depending on the conditions and, as a rule, decreases significantly with timely medical care. This is not the most common infection, but where it occurs, vaccination does not hurt. Infection through the patient's blood is possible, but, for example, it is impossible to become infected through a mosquito bite. The disease can last from several to 20 days," he said.
The Hyalomma tick population is indeed migrating north, and the prevalence of the Congo-Crimean hemorrhagic fever virus will strongly depend on how hot the spring-summer season will be, the director of the Institute of Veterinary Medicine, Veterinary and Sanitary Expertise and Agro-Safety at the Russian Biotechnological University (ROSBIOTECH) explained to Izvestia Igor Glamazdin.
— It is difficult to say whether these ticks will be able to cause an epidemic in our middle zone, since the virus itself develops well at high temperatures. This is likely during hot summers. But the vaccine must be developed in any case and the technology must always be improved. The ticks will probably migrate further. Judging by the other parasites that weren't here before, this process is underway. Therefore, we need to prepare. And the vaccine is the only specific agent that acts on the causative agent of infection," the scientist said.
As a virologist at one of the academic institutes studying pathogens and their effects on humans told Izvestia, about ten people fall ill with Congo-Crimean hemorrhagic fever in Russia every year. In this regard, the development of a vaccine is not considered economically feasible.
— However, the drug is still necessary, since there may be cases of secondary infection through the blood of an infected person. Then the disease may be more severe. The drug may be especially important for medical professionals. Humans are not the most suitable prey for Hyalomma ticks, large animals are more suitable for them. If a person does get infected, then there are good diagnostic methods. The patient is quarantined so that there is no nosocomial spread of the infection. There are already established treatment regimens. In particular, the introduction of platelet mass can reduce the risk of death, although the disease as a whole is severe," the specialist said.
According to the source, vaccine prototypes in case of possible outbreaks are being developed in many countries. Probably, certain developments exist in the Gamalea center, otherwise it would take years to create a drug from scratch.
Переведено сервисом «Яндекс Переводчик»
