The SARS-CoV-2 virus is the cause of the communicable disease COVID-19.
COVID-19′s initial case was discovered in Wuhan, China, in December 2019.
The World Health Organisation (WHO) declared a pandemic in March 2020 as a result of the disease’s rapid global spread.
Symptoms of COVID-19 can vary but commonly include:
Loss of smell (anosmia)
Loss of taste (ageusia)
After being exposed to the virus, symptoms often start to manifest one to fourteen days later.
Among those that exhibit symptoms:
81% of people experience mild to moderate symptoms, such as mild pneumonia.
14% of patients experience severe symptoms such as dyspnea, hypoxia, or imaging findings of more than 50% lung involvement.
Critical symptoms, such as respiratory failure, shock, or multiorgan dysfunction, appear in about 5% of patients.
SARS-CoV-2: Coronavirus SARS-CoV-2 is a kind that causes COVID-19, a respiratory disease. It was initially discovered in Wuhan, China, and since then has spread throughout the world, causing the COVID-19 pandemic.
Initial names: Based on the year of its discovery, the virus was first given tentative names such as 2019 novel coronavirus (2019-nCoV) and human coronavirus 2019 (HCoV-19 or hCoV-19).
Emergency in Public Health: On January 30, 2020, the World Health Organisation (WHO) deemed the COVID-19 outbreak an international emergency in public health. Up to May 5, 2023, this classification was in force.
Viral Characteristics: A positive-sense single-stranded RNA virus, SARS-CoV-2, infects people. When an infected individual coughs, sneezes, talks, or breathes, respiratory droplets are the main method of transmission in humans, making it extremely contagious.
Variants: Multiple SARS-CoV-2 variants have developed throughout time as a result of genetic changes in the virus. Due to certain traits, some of these variations have been identified as possibly significant.
Different types of variants
Delta variant: The SARS-CoV-2 virus, which produces COVID-19, has a variant called the Delta variant (B.1.617.2). On October 5, 2020, India reported the first detection of it. The Delta variety was predicted to overtake other strains globally by the World Health Organisation (WHO) in June 2021.
Omicron Variant: On November 24, 2021, the Network for Genomics Surveillance in South Africa notified the World Health Organisation (WHO) about the SARS-CoV-2 variant Omicron (B.1.1.529). It was first discovered in Botswana and has since spread to become the most common variety in use worldwide.
Alpha Variant: A SARS-CoV-2 variation of concern was the Alpha variant (B.1.1.7). It was calculated to be 40–80% more contagious than the SARS-CoV-2 wild type. Early in December 2020, when a phylogenetic tree displaying viral sequences from Kent, United Kingdom, seemed strange, more researchers became aware of this variation.
Gamma Variant: One of the SARS-CoV-2 variations that induce COVID-19 is the Gamma variant (P.1). The National Institute of Infectious Diseases (NIID) of Japan discovered this strain of SARS-CoV-2 for the first time on January 6, 2021, in four visitors to Tokyo who had just returned from a four-day trip to Amazonas, Brazil. After that, it was acknowledged as being in circulation in Brazil.
Beta Variant: The virus that causes COVID-19, SARS-CoV-2, has a beta variant (B.1.351). It was discovered for the first time in the Nelson Mandela Bay metropolitan region of the Eastern Cape province of South Africa in October 2020, one of several SARS-CoV-2 variations previously thought to be of particular relevance.
About: The Omicron variation, also known as B.1.1.529, was discovered in South Africa in November 2021 as a result of genomic surveillance.It has several mutations, some of which raise questions about its capacity to circumvent immunity from prior infections or vaccinations.
Spike protein mutations: The spike protein, a component of the virus that allows it to enter human cells, has many alterations in the Omicron variety. These alterations are problematic because they could have an impact on immune response and transmissibility.
Transmissibility: Compared to earlier versions, especially the Delta variant, the Omicron form is highly transmissible and spreads quickly. Rapid increases in COVID-19 cases have been attributed to this increased transmissibility.
Omicron Detection: Cases of the Omicron variation have also been documented in other nations than South Africa, where it was initially found. These include Israel, where people from Belgium, Hong Kong, Botswana, Malawi, and has tested positive for the variation.
India’s situation: According to seroprevalence studies, a sizeable section of the country’s population has already been exposed to the virus, offering some degree of protection against recurring infections. With around 44% of Indian adults having received all recommended vaccinations and 82% having received at least one dose, the immunisation campaign has gained traction.
Protection: According to researchers, a prior infection followed by one or two vaccination doses may provide a higher level of defence than two vaccination doses by itself. This shows that boosting defences against the virus requires both natural immunity from prior infection and vaccination.Drug Controller General of India (DCGI) late on Monday authorised GEMCOVAC-OM, India’s first indigenously developed mRNA vaccine for the new coronavirus Omicron strain.