In December 2019 there was a cluster of pneumonia cases in the city of Wuhan in China. Some of the cases have reported visiting seafood & live animal markets in Wuhan. As per the Investigations, the disease was caused by a newly discovered coronavirus (SARS COV-2), the disease was subsequently named Covid- 19. The COVID-19 spreads within China & the rest of the world.
On the 30th of January 2020, the World health organization declared a public emergency of international concern.
A coronavirus is a large group of viruses. They consist of a core genetic material surrounded by a lipid envelope with protein spikes. This gives the appearance of a Crown. In Latin crown means corona that's why it is named "Coronavirus". There are multiple types of coronavirus that cause illness in animals & humans. In humans, coronavirus can cause respiratory infections ranging from the common cold to severe diseases to include the SARS- Cov.
The coronavirus circulates in a range of animals. Sometimes these viruses can make the jump from animals to humans this is called spillover. It could be due to a range of factors such as mutations in the virus or increased contact between animal & human. For example - MER -cov is known to be transmitted from camels & SARS-cov from the cats.
Cases of 2 potentially more contagious coronavirus variants have been found worldwide.
The UK first detected a new strain in September.
It is estimated to be up to 70% more transmissible.
In December, South Africa reported another mutated Covid-19 strain similar to the UK variant.
The 2 variants have already spread across the world.
On December 29, India reported its first case of the variant to seem in Britain.
As of December 28, Japan had found 8 cases of the same new strain.
The coronavirus was in a constant arms race against our immune system. It was assumed that the virus would keep evolving. A variant is a virus with a specific set of mutations.
Three distinct variants of the virus seem to have independently converged on some of the same variants that seemed to become more common & more transmissible. Spike protein is how the coronavirus enters cells. N510v is in a region called receptor binding domain which latches on the cell. It was estimated that N501y mutation may make the spike protein sticker, allowing it to bind to & enter cells more readily.
What is unusual about these variants is that they also have an additional constellation of other mutations in other parts of the virus.
The UK variant has more than a dozen other mutations. The growth of this mutation was more prevalent not just in the UK. The South Africa variant also has a 2nd mutation in common in the spike's receptor-binding domain E484k.
The E484K mutation switches a negatively charged amino acid for a positively charged one. It is like flipping a magnet.
South Africa was originally found in parts of the countries that have had high levels of covid-19 infection, especially in Manaus.