Vaccine trial soon amid fear of Ebola virus spread to other countries
- November 6, 2022
- Posted by: OptimizeIAS Team
- Category: DPN Topics
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Vaccine trial soon amid fear of Ebola virus spread to other countries
Subject: Environment
Context- Ebola outbreak in Uganda
More on the news-
- The Ebola virus outbreak that began in Uganda on September 20 after one case was confirmed in Mubende district the previous day has spread to at least 130 people (lab confirmed) and caused 43 deaths as on November 2.
- The increase in fatalities has in turn increased the case fatality rate among lab-confirmed cases to 33% (43/130); the case fatality rate was 26.5% (34/128) as on October 29.
- The deadly virus has now reached the capital city Kampala which was restricted to the rural areas of Uganda since the outbreak began in September.
Difficulty in tracing-
- Spreading of the virus to the cities entails an increased risk of the virus spreading to a large population and the increased difficulty of tracing.
- The virus has already spread to school children.
- Also, there is a risk of the virus spreading across borders.
A rare strain of ebola virus-
- Unlike the large Ebola outbreak of 2014-2016 caused by the Zaire strain that started in Guinea and spread to two other Western African countries — Sierra Leone and Liberia — by July 2014, the outbreak in Uganda is caused by the relatively rarer Sudan strain.
- Uganda is facing a Sudan Ebola virus outbreak after a decade.
Vaccine against the Sudan strain of Ebola virus-
- The Ebola outbreak of 2014-2016 which spread to over 28,000 people and killed 11,000 people allowed the testing of Merck’s vaccine through a ring vaccination strategy.
- Currently, there are no vaccines available for the Sudan strain of the Ebola virus.
- Merck developed a vaccine specifically against the Sudan strain in 2015 and 2016 after the success of the vaccine against the Zaire strain.
- Besides Merck’s vaccine for the Sudan strain, two other vaccines by the Sabin Vaccine Institute and the University of Oxford are in the process of being produced for clinical testing.
- While Merck’s vaccine uses the VSV (vesicular stomatitis virus) platform, both Sabin Vaccine Institute and the University of Oxford use the chimpanzee adenoviruses to carry the virus protein into humans, much like in the case of the AstraZeneca COVID-19 vaccine.
- Clinical trials using the ring vaccination strategy of administering the vaccine among the contacts might begin by mid-November.
Ring vaccination strategy of administering the vaccine-
- Ring vaccination is a strategy to inhibit the spread of disease by vaccinating those who are most likely to be infected.
- This strategy vaccinates the contacts of confirmed patients, and people who are in close contact with those contacts.
- This way, everyone who has been, or could have been, exposed to a patient receives the vaccine, creating a ‘ring’ of protection that can limit the spread of a pathogen.
- Ring vaccination requires thorough and rapid surveillance and epidemiologic case investigation.
- The Intensified Smallpox Eradication Program used this strategy with great success in its efforts to eradicate smallpox in the latter half of the 20th century.
About Ebola virus disease (EVD)-
- EVD, formerly known as Ebola haemorrhagic fever is a deadly disease with occasional outbreaks that occur mostly on the African continent.
- The Ebola virus was first discovered in 1976 near the Ebola River in what is now the Democratic Republic of Congo.
- It most commonly affects people and nonhuman primates (such as monkeys, gorillas, and chimpanzees).
- It is caused by an infection with a group of viruses within the genus Ebolavirus:
- Ebola virus (species Zaire ebolavirus)
- Sudan virus (species Sudan ebolavirus)
- Taï Forest virus (species Taï Forest ebolavirus, formerly Côte d’Ivoire ebolavirus)
- Bundibugyo virus (species Bundibugyo ebolavirus)
- Reston virus (species Reston ebolavirus)
- Bombali virus (species Bombali ebolavirus)
Host: Fruit bats of the Pteropodidae family are natural Ebola virus hosts.
Transmission:
- Animal to Human Transmission occurs through close contact with the blood, secretions, organs or other bodily fluids of infected animals such as fruit bats, chimpanzees, gorillas, monkeys, forest antelope or porcupines found ill or dead or in the rainforest.
- Human-to-Human Transmission occurs via direct contact (through broken skin or mucous membranes) with the Blood or body fluids of a person who is sick with or has died from Ebola.
- Signs and Symptoms: Symptoms may appear anywhere from 2 to 21 days after contact with the virus, with an average of 8 to 10 days which include Fever, Fatigue, Muscle pain, Body weakness, Headache, Sore throat, Vomiting, Diarrhea, Symptoms of impaired kidney and liver function, in some cases, both internal and external bleeding.