There is a pandemic outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which caused Novel coronavirus disease in 2019. With time Coronavirus has shown a lot of mutations, and there are many variants of this virus. According to the WHO, the variants of the Covid-19 are as follows:
Variants of concern:
Variants of interest:
The deadly variants are listed by the World Health Organization (WHO) under the variants of concern.
The variant Alpha is also known as B.1.1.7. This variant is 40–80% more transmissible than the wild-type SARS-CoV-2. This variant was detected in November 2020 from a sample taken in September in the United Kingdom and began to spread quickly by mid-December, around the same time as infections surged.
The Beta variant of SARS-Covid-2 is also known as B.1.351. This variant was detected in October 2020 in South Africa and was reported by the country’s health department on 18 December 2020. Reports were that the prevalence of the variant was higher among young people with no underlying health conditions. By comparison with other variants, it is more frequently resulting in serious illness in those cases.
According to the WHO reports, the Gamma variant of SARS-Covid-2 was detected in Tokyo on 6 January 2021, who travelled from Brazil. It was labelled by WHO as Gamma. According to a study, infections caused by Gamma can produce nearly ten times more viral load compared to persons infected by one of the other variants identified in Brazil. This variant or variants like this is more successful at infecting younger humans irrespective of sex. Gamma showed a 2.2 times higher frequency of spreading with the same ability to infect both adults and older persons.
The Delta variant of SARS-Covid-2 is also known as B.1.617.2. It was first detected in India in October 2020. It is a globally dominant variant that has spread to at least 185 countries. It spread more quickly than the original version of the virus and could spread quicker or as promptly as the Alpha variant, and reports were that it was among the fully vaccinated people.
WHO labelled this new variant of SARS-Covid-2 as Omicron or B.1.1.529. This variant was detected in multiple countries in November 2021. This variant shows a large number of mutations. There are many increasing cases found in South Africa. Some evidence indicates that this variant has an increased risk of reinfection (who have been fully vaccinated or infected by the Covid-19 virus). Research and studies are going on about transmissibility and mobility. Current SARS-CoV-2 PCR diagnostics continue to detect this variant. Several labs have recommended that one of the three target genes is not detected (called S gene dropout or S gene target failure). This test can therefore be used as a marker for this variant, pending sequencing confirmation. By using this approach, this variant has been detected at faster rates than previous surges in infection, suggesting that this variant may have a growth advantage.
The virus is constantly changing, and that’s how a new variant or strain occurs. Variants have similar characteristics, but they can carry additional properties due to mutation in their genetic material RNA. Scientists around the world are studying the new variants, the changes in them and how they will affect people.