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Two experimental Zika virus vaccines worked in mice: it took one dose

The World Health Organization has recognized the Zika virus outbreak in South and North America as an emergency. In 2015, scientists said that the virus causes microcephaly in infants, and doctors registered more than 4,000 such cases in Brazil. The virus from Africa came close to the United States - at the moment five children were born in the country with this anomaly, and in February 2016 the first case of infection was registered in Russia .



Because of the belief that Zika virus does not cause irreversible changes and death in humans, they have not developed a vaccine for it, which increases the risk of the disease. American scientists published the results of an experiment in Nature: two virus vaccines worked on mice, which makes it possible to work further in search of a vaccine for humans.



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The virus causes the same type of anomalies of the fetus in humans and in mice, penetrating through the placenta. Scientists from the Beth Israel Deaconess Medical Center and the Harvard Medical School have published the results of testing two types of vaccine in pregnant female mice. The first vaccine contains virus DNA fragments, the second - inactive virus particles. In both cases, a single drug injection helped protect mice from Zika virus strains obtained from patients from Brazil and Costa Rica. Vaccines caused the production of antibodies, and the animals then showed complete resistance to the disease.

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A few days after taking the vaccine, no virus was found in the mice. Protection lasts at least two months. At the same time, a high level of the virus in the blood was recorded in the control group.



Creating drugs based on DNA and an inactive virus are two common ways to develop vaccines. Two commercial companies received permission from the Food and Drug Administration to test DNA-based vaccines in humans.



Zika virus is transmitted by mosquitoes of the genus Aedes, transmission from male to female is possible - the virus was detected in the semen and urine of patients. It causes rashes, fatigue, headache and joint pain, fever and joint swelling. He was discovered in 1947 in the forest of Zeke in Uganda, and in 1968 found in people in Nigeria. In total, up to 2014, fifteen cases of the disease were reported, according to doctors, not dangerous for humans and occurring within a few days. Later during epidemics, scientists suggested that the virus causes Guillain-Barré syndrome and microcephaly in infants.



Guillain syndrome - Barre is manifested by sensitivity disorders and autonomic disorders. Patients have symmetrical paralysis of the leg muscles, which gradually spreads to the arms. In severe cases, paralysis comes to the respiratory muscles, which can cause death from respiratory failure. During the epidemic in French Polynesia, with a population of 270,000 people, 73 cases of the syndrome were revealed, which may be due to a virus.



In Brazil, in 2014, up to 150 cases of microcephaly were registered in infants, and in 2015, during the Zika virus epidemic, this number increased to 4180. Then the director general of the World Health Organization noted that the causal link between the virus and the developmental disabilities of children was not established , but "there are strong suspicions about its existence." In November 2015, the Brazilian authorities confirmed that infection during pregnancy causes microcephaly in the child, and in January 2016, the authorities of El Salvador asked residents of the country not to give birth within two years.



On this occasion, sounded the alarm in the United States: at the moment, five babies were born with this anomaly. Florida Governor Rick Scott signed a government order to allocate $ 26 million to prepare and respond quickly to the Zika virus, but the US Senate did not support the funding .

Source: https://habr.com/ru/post/369433/



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