Category Science

What are the different stages of vaccine development?

Nine months into the COVID-19 pandemic, scientists and pharmaceutial companies around the world are racing to develop an effective vaccine against SARS-CoV-2, the coronavirus that causes COVID-19. According to the latest list of the World Health Organization (WHO), at least 200 vaccines are at various stages of development.

According to Russian State media, the first batch of Russia’s vaccine, Sputnik V, entered “civil circulation” on September 24 in capital Moscow. However, its safety and effectiveness is being looked at sceptically because the results of only the phases 1 and 2 of the trials have been published. Earlier, reports emerged that the third stage trials were ongoing in Russia and a few other countries. Phase 3 of clinical trials of the Sputnik V vaccine will begin in India in the coming weeks.

China has about 11 vaccine candidates in various stages of human testing. China has been administering experimental coronavirus vaccines to large numbers of workers deemed to be at high risk of exposure to the virus. They include frontline health workers, public service workers and border officials. A vaccine developed by CanSino Biologists and named Ad5-nCoV was approved for use within the Chinese military as early as June 2020. Four other vaccines are in the final stages of clinical trials. Chinese officials say that the country will be able to roll out a vaccine for public use by November or December. China has promised to provide doses to at least 62 countries.

Among other vaccine contenders that have drawn global attention is the one being developed by the Oxford University in partnership with phaemaceutical company AstraZeneca. Hopes were high when it successfully carried out phases 1 and 2 of the trials. But the final clinical trials had to be briefly put on hold in September after a study participant developed a suspected serious adverse reaction.

COVID-19 vaccines are also being developed by Pfizer and BioNTech in the U.S. and Germany; Johnson and Johnson in the U.S.; Sanofi along with GlaxoSmithKline in the U.K. and Franc; and Novavax in the U.S. Some of these companies have signed deals with multiple countries for trials.

Back home, in India, there are at least eight vaccine candidates under development. The phase 3 clinical trial of ‘Covishield’, being developed by Oxford University and the Serum Institute of India, is underway. Indian candidates, Covaxin, by Bharat Biotech, and ZyCoV-D, by Zydus Cadila, are currently in phase 2 trials.

Experts maintain that even at this speed a vaccine will not be ready before mid-2021.

 

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Why three major telescopes hit the headlines in 2020?

China’s Five-hundred-metre Aperture Spherical Radio Telescope (FAST) passed national evaluation and officially began operation in January 2020. With a dish the size of 30 football fields, it is the world’s largest single-dish radio telescope and the most sensitive listening device. The single-dish radio telescope is made of 4,450 individual panels.

The facility will help scientists learn more about the Universe’s early days, detect low-frequency gravitational waves and hunt for signals that may have been produced by distant alien civilizations.

  • NASA’s Spitzer Space Telescope was retired in January 2020. Launched in 2003, Spitzer studied the universe in infrared light, revealing wonders of the Solar System, our galaxy, and beyond. Among its many scientific contributions, Spitzer studied comets and asteroids in the Solar System and found a previously unidentified ring around Saturn.
  • In April 2020, the Hubble Space Telescope completed 30 years of service. Perched on the low Earth orbit, the telescope’s modest 2.4-metre mirror continues to give us an unprecedented window on the Universe. Thanks to Hubble and the Gaia space observatory, we were able to calculate the age of our Universe, which is approximately 13.8 billion years old. From observations from Hubble, we also learnt that black holes are at the centre of almost every major galaxy.

Did you know?

  • NASA’s James Webb Space Telescope (JWST) is scheduled to be launched in October 2021. While it is touted as the successor of the Hubble Space Telescope, some scientists believe the two telescopes are actually complementary. Hubble has limited capabilities at near-infrared wavelengths, but it is best suited for observing in the ultraviolet and optical ranges of the light spectrum. Whereas James Webb is perfectly poised to study things in infrared range and these include formation of stars and planets, extremely distant galaxies, and even the atmospheres of exoplanets.
  • The Hubble’s mission ends in 2021, unless NASA decides to extend it.

 

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Why are deserts dry?

Deserts are the driest places on Earth. In some deserts it doesn’t rain for years at a time. In others, it never rains at all. Some deserts are also scorching hot. In the daytime, the sand’s hot enough to fry an egg on.

Can sand dunes move?

Strong winds blowing across the desert pile the sand up into giant heaps, or dunes. The biggest stand 200 metres tall. The dunes creep forward every year and can bury whole desert villages.

Amazing! The Sahara Desert is the biggest, sandiest desert in the world. It covers about a third of Africa.

Are all deserts sandy?

No, they’re not. Only about a quarter of all deserts are sandy. Most deserts are rocky or covered in gravel and stones. Some deserts have high mountains or strange-shaped rocks towering up from the ground.

Is it true? Mushrooms grow in the desert.

Yes. Well mushroom-shaped rocks. They’re carved into shape by sand blown by the wind, like a giant piece of sandpaper.

Picture Credit : Google

Which lake is the biggest?

The biggest freshwater lake on Earth is Lake Superior in North America. It covers 82,350 square kilometres. That’s almost as big as Austria. Lake Superior is one of five huge lakes called the Great Lakes.

Amazing! The Dead Sea in the Middle East is so salty; you can float on the surface. No fish can live in it.

Is it true? There’s a monster in Loch Ness.

Maybe. Some people say Nessie is a type of prehistoric reptile that lives in the lake. Others say this is nonsense. What do you think?

Where is the highest lake?

Lake Titicaca in South America is the highest lake on which boats can sail. It’s 3,810 metres up in the Andes Mountains. People who live around the lake build boats from lake reeds.

How are lakes made?

Some lakes formed long ago, in hollows scraped out by ice. These filled with water as the ice melted. Some lakes form in the tops of volcanoes or when a river cuts through a bend.

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Where do rivers begin?

Rivers begin as fast-flowing streams high up on mountainsides. Some streams bubble up from underground. Others flow from lakes or trickle from the tips of icy glaciers when they start to melt. The start of a river is called its source.

Amazing! The world’s shortest river is D River in Oregon, USA. It’s a titchy 37 metres long. Is the Nile or the Amazon the longest river?

The Nile in Egypt is the longest river on Earth. It flows for 6,695 kilometres. The Amazon in South America is just 295 kilometres shorter.

How high are waterfalls?

The highest waterfall in the world is Angel Falls in Venezuela. It plunges 979 metres down the side of a mountain. Angel Falls are 20 times higher than the famous Niagara Falls in North America.

Is it true? Rivers flow into the sea.

Yes. Most rivers flow into the sea at their deltas. But some rivers flow into lakes and a few flow into deserts.

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Why does the sea flow in and out?

Twice a day, the sea washes on to the shore at high tide. Then it flows back out again at low tide. The tides are caused by the Moon and Sun pulling the sea into giant bulges on either side of the Earth.

Amazing! If all the coasts were straightened out, they’d stretch round the Earth 13 times. At 90,000 kilometres, Canada has the longest coast.

Why are beaches sandy?

Sand is made from tiny fragments of rock and shells, crushed up by the wind and water. Sand is usually yellow or white. But some sand is black because it contains volcanic rock or coal.

How are cliffs carved out?

Along the coast, the rocks are worn away by the force of the waves. As the waves crash against the shore, they carve out cliffs, caves and high arches. Sometimes an arch collapses, leaving a stack, or pillar, of rock.

Is it true? White horses swim in the sea.

Yes. But they’re not real horses. They’re the white, foamy tops of the waves as they gallop towards the shore.

Picture Credit : Google