Yes, there is an L strain and an S strain. At first it was feared that one strain was more aggressive but this is now in doubt. Coronaviruses tend not to mutate quickly and tend not to have significant changes when they do mutate.
There are many lineages. It is not clear yet whether any of them are significantly different. There is a nomenclature proposal being discussed at virological.org, but not clear yet if it will be adopted.
http://virological.org/t/a-dynamic-nomenclature-for-sars-cov-2-to-assist-genomic-epidemiology/458
COVID-19 is a novel coronavirus with an outbreak of unusual viral pneumonia in Wuhan, China, and then pandemic. Based on its phylogenetic relationships and genomic structures the COVID-19 belongs to genera Betacoronavirus. Human Betacoronaviruses (SARS-CoV-2, SARS-CoV, and MERS-CoV) have many similarities, but also have differences in their genomic and phenotypic structure that can influence their pathogenesis. COVID-19 is containing single-stranded (positive-sense) RNA associated with a nucleoprotein within a capsid comprised of matrix protein. A typical CoV contains at least six ORFs in its genome. All the structural and accessory proteins are translated from the sgRNAs of CoVs. Four main structural proteins are encoded by ORFs 10, 11 on the one-third of the genome near the 3′-terminus. The genetic and phenotypic structure of COVID-19 in pathogenesis is important. This article highlights the most important of these features compared to other Betacoronaviruses.
Coronavirus (SARS-CoV-2) has mutated into 30 different strains.
https://www.medrxiv.org/content/10.1101/2020.04.14.20060160v2.full.pdf
The theory about different strains of the new coronavirus comes from a study in China. Researchers were studying changes in coronavirus RNA over time to figure out how various coronaviruses are related to each other. They looked at 103 samples of the new coronavirus collected from people, and they looked at coronaviruses from animals. It turned out that the coronaviruses found in humans weren’t all the same.
There were two types, which the researchers called “L” and “S.” They’re very similar, with slight differences in two places. It looks like the S type came first. But the scientists say the L type was more common early in the outbreak. One may cause more disease than the other. Scientists need more data to really know what these strains mean to human health and COVID-19.
Pl. have a look at the following link:
https://www.nature.com/articles/s41591-020-0820-9
https://thehill.com/changing-america/well-being/prevention-cures/494371-coronavirus-has-mutated-into-more-than-30
Three central variants of SARS-CoV-2 named A, B, and C are of epidemiological relevance, spread and mortality all over the world.
For details read this interesting article:
Article Phylogenetic network analysis of SARS-CoV-2 genomes
The mutation is a continuous process in its life cycle. The crucial questions about this mutation are: does this make the virus more infectious - or lethal - in humans? And could it pose a threat to the success of a future vaccine?
18 July, BBC
The notable mutation - named D614G and situated within the protein making up the virus's "spike" it uses to break into our cells - appeared sometime after the initial Wuhan outbreak, probably in Italy. It is now seen in as many as 97% of samples around the world.
18 July, BBC
It can have several strains because it has RNA genome which lack exonuclease activity and mutations lead to novel strains
It's more than two actually and mutations are making it more infectious according to study findings.
19 July, BBC
I agree with the answer of Dr. Arvind cocerning the different strains of COVID-19.
Here are some strains: 2019-nCoV, SARS-CoV, and MERS-CoV
Source: CDC, 2020
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There are two strains. The first is the L strain which was seen in Wuhan but is now almost gone. The second strain is the G strain which is predominant in Europe.
Currently, there are.... strains of coronavirus. The original one is the L strain, that appeared in Wuhan in December 2019. Its first mutation -- the S strain -- appeared at the beginning of 2020, while, since mid-January 2020, we have had strains V and G.
https://www.sciencedaily.com/releases/2020/08/200803105246.htm
Kindly check https://www.who.int/bulletin/volumes/98/7/20-253591/en/
Dear Owayes M. Hamed, please follow the link for an insight on major Covid strains.
https://www.cnbc.com/2021/01/12/covid-mutations-all-the-major-strains-we-know-about.html
https://www.researchgate.net/deref/https%3A%2F%2Fwww.who.int%2Fbulletin%2Fvolumes%2F98%2F7%2F20-253591%2Fen%2F
