Science and Technology Current Affairs

Two Experimental Ebola vaccines found safe, effective in human trial

The clinical trials of two experimental Ebola vaccines cAd3-EBOZ and rVSV-ZEBOV were found to be safe and capable of eliciting immune response against Ebola virus that lasts for at least one year.

The findings were based on a study of clinical trials on 1,500 adults that began during West Africa Ebola outbreak. Three groups of 500 volunteers received one of the vaccine candidates or a placebo (saline injection).

Key Facts

During clinical trials, it was observed that responses to both vaccine candidates were modest at one week. However, by one month, 71% of cAd3-EBOZ recipients and 84% of rVSV-ZEBOV recipients developed an antibody response compared to 3% of placebo recipients.

These trials have yielded valuable information for development of these two Ebola vaccine candidates and also demonstrated that well-designed, ethically sound clinical research can be conducted during an epidemic. These safe and effective Ebola vaccines will play important role in controlling inevitable future Ebola outbreaks in addition to existing classical public health measures.

Ebola virus disease (EVD)

EVD is viral hemorrhagic fever of humans and other primates caused by ebola viruses. It was first identified in 1976 in the Democratic Republic of Congo (DRC) in a village near the Ebola River, from which it takes its name. The virus is transmitted to people from wild animals and spreads in human population through human-to-human transmission. Fruit bats are natural host of this virus. It spreads through contact with body fluids of inflected persons such as blood, urine and saliva.

It also spreads through sexual transmission. Symptoms of EVD are high fever, bleeding and central nervous system damage. The average EVD case fatality rate is around 50%. However, in past outbreaks case fatality rates have varied from 25% to 90%. In 2014, Ebola virus had erupted periodically mainly across west and east Africa mainly in Guinea, Liberia and Sierra Leone. It was the deadliest outbreak of the virus in the history which had killed 11,000 people.

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Japan launches fourth Michibiki satellite for hi-tech GPS

The Japan Aerospace Exploration Agency (JAXA) successfully launched Michibiki-4 satellite (QZSS-4) onboard of H-IIA rocket from Tanegashima Space Centre.

It was fourth satellite in Michibiki series i.e. Quasi-Zenith Satellite System (QZSS), which is a satellite-based high-precision global positioning system similar to US operated GPS. Moreover, it was 36th H-IIA vehicle to be launched so far and fifth launch of an H-IIA rocket in 2017.

QZS-4 (Michibiki-4)

Michibiki-4 is third QZSS satellite to be launched in 2017 and once operational it will bring the constellation of QZSS to its operating capacity of four until a planned expansion to 8 satellites occurs around 2023.

Quasi-Zenith Satellite System (QZSS)

It is own version of GPS and is dubbed as Michibiki system. Michibiki means guidance in Japanese. It is intended for civilian use, with a claimed positioning accuracy down to mere centimetres. The QZSS constellation of 8 satellites will trace out a figure-8 pattern over Japan, the Western Pacific, and Australia.

The Michibiki system can cover the Asia-Oceania region and works with the US-operated GPS to provide higher level of precision than previously possible with fewer satellites in visible range. It will become operation in 2018 with four satellites focusing on country and wider region. It will provide global positioning and timing services across frequencies ranging from 1575.42 MHz to 2 GHz.

H-IIA rocket

The H-IIA rocket is Japanese large-scale launch vehicle. It was manufactured by Mitsubishi Heavy Industries. The vehicle stands 53 meters tall and generates 1.7 million pounds-force (7,628 kilonewtons) of thrust at liftoff.

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