A first case of hemorrhagic fever due to the Ebola virus was discovered in an urban area, in Mbandaka, in the Democratic Republic of the Congo. Faced with the growing risk, the country has just accepted the deployment of an experimental vaccine.
Faced with the urgency of the situation, the Democratic Republic of the Congo (DRC) has decided: from Tuesday, May 22, an experimental vaccine against Ebola will be deployed in the country to eradicate the epidemic currently raging in the north-west of the country. country. Since the beginning of April, the region of Bikoro, very remote and mainly rural, has been affected by the Ebola virus. In total, around 40 cases including 23 deaths were recorded between April 4 and May 9. According to The world, three sources of contamination were identified and nearly 400 people who had been in contact with the sick were placed under observation.
A first case of hemorrhagic fever was also discovered in an urban area, in Mbandaka (1 million inhabitants), in the north-west of the country. “A new case (…) has been confirmed in Wangata, one of the three health zones in Mbandaka, a town of nearly 1.2 million inhabitants in Equateur province, in the north-west of the country. DRC“, said the World Health Organization.
It is in the face of the risk of spread to densely populated cities such as the capital Kinshasa (11.5 million inhabitants) that the authorities have given the green light to the World Health Organization (WHO) to ship the first doses. vaccine. “If a city of this size is affected by Ebola disease, there will be a significant urban focus, which will be a real challenge,” World Peter Salama, who heads emergency operations at WHO: “When Ebola spreads to urban areas, especially slums, it is extremely difficult to overcome the disease.”
A vaccine successfully tested in 2015 in Guinea
Known by the code name V920, the vaccine was developed by the Merck laboratory in 2016. When administered as a single dose, it has so far been shown to be successful in clinical trials in humans, but has not still received marketing authorization (AMM). On the other hand, it was successfully tested in 2015 in Guinea, when the Ebola epidemic in West Africa caused more than 11,000 deaths, was drawing to a close.
Published in 2017 in the journal The Lancet, the results of the V920 vaccine give hope for an end to the epidemic in the DRC. In fact, of the 6,000 people vaccinated, including 200 children, none contracted the disease in the weeks following vaccination. On the other hand, the researchers admit not knowing the duration of protection conferred by the vaccine.
4,000 vaccine doses sent
The objective of the competent authorities is now to “break the chains of transmission” of Ebola, explains Professor Denis Malvy, specialist in infectious and tropical diseases at the Bordeaux University Hospital. It is therefore necessary to trace and isolate all the people with whom the patients have been in contact so that they can receive the vaccine as a priority with the nursing staff.
At present, WHO has 4,000 vaccines which will be airlifted from next week to the Bikoro region. At least 300,000 other doses of the V920 vaccine are available and will soon be shipped to the DRC. They constitute an emergency stock set up in early 2016 by Merck and Gavi, an international organization that wants to promote access to vaccines in developing countries. The logistical challenge is now to transport the vaccine and store it while respecting the cold chain: it must indeed be stored at -80 ° C.
Ebola transmission chains
The DRC officially announced the end of the Ebola epidemic on its soil last July. This new outbreak is the ninth to be declared in the country since 1976. The Institut Pasteur took action and succeeded in reconstructing the chains of transmission of the Ebola virus and their context, within the Guinean capital in 2015. This survey work, carried out with patients, their families and their neighbors, made it possible to measure the transmission of Ebola between individuals in different contexts and at different times during the epidemic.
Illustration: Ebola virus transmission trees. In the circles are written the dates of onset of symptoms for cases having infected more than 3 people. The size of the circles is proportional to the number of people the case has infected. Source: Pastor Institute
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