WHO classification of new crown virus variant strains, how to detect new crown nucleic acid rapid test
Currently, Delta variant strains have become the main New Coronavirus strains prevalent worldwide. Compared to other variant and original strains, Delta variant strains have higher viral load, higher transmission capacity, shorter incubation period, faster onset of disease, and slower turnaround of nucleic acid tests during treatment. The good news is that the new coronavirus nucleic acid rapid test is not affected for now.
Computer-simulated structure of a novel coronavirus
Source: Janet Iwasa, University of Utah
The World Health Organization (WHO) classifies new coronavirus variant strains into two major categories according to their virulence and risk factors: VOC (variant of concern) and VOI (variant of interest).
WHO classifies five new coronavirus strains of concern
The main characteristics of VOC include: increased transmission or deleterious changes in epidemiological characteristics; increased pathogenicity or more severe clinical manifestations; and reduced effectiveness of public health and social interventions or existing diagnostic, vaccine, and treatment methods.
The Delta variant is one of the strains, which is in fact the first Neocoronavirus B.1.617.2 previously identified in India.
Alpha: First released in the UK, to become the dominant neocoronavirus variant in the first half of 2021
The Alpha variant was first identified in the United Kingdom in November 2020, but did not receive much attention at the time, and then began to sweep the United Kingdom, becoming the dominant neo-coronavirus variant in the United States by April 2021. These mutations have been found to make the virus more difficult to detect by the human immune system, and the clinical symptoms caused by Alpha are more intense.
Beta: first appeared in South Africa, with very strong immune escape
The main mutations in the Beta strain are K417N, E484K, and N501Y, which increase the transmission of the virus and improve immune escape.
Gamma: first in Brazil, the biggest threat to the South American epidemic
The Gamma mutant strain is the most prevalent new coronavirus strain in South America, first discovered in Brazil in November 2020, and then gradually spread in South America, becoming the most prevalent new coronavirus strain in the continental epidemic in South America. Some studies have reported that Gamma is 1.4 to 2.2 times more infectious than the original strain, and there is also a risk of secondary infection.
Delta: First reported in India, currently the most infectious mutant strain
The Delta variant was first identified in India in October 2020 and was the main strain responsible for the second major outbreak in India in April this year. After the outbreak in India, the Delta variant began to sweep the world, with 132 countries or regions having reported cases of Delta variant infection, and has been the most prevalent strain in new cases worldwide.
As the epidemic continues and the virus continues to spread, mutations of the virus will accumulate. In the face of the prevalence of mutated strains, we need to strengthen prevention and control measures in all aspects: the frequency of rapid testing of NICs should be increased, epidemiological investigation should be accelerated, and vaccination should be accelerated. Each Nucleic Acid Rapid Test Institute should ensure the detection ability of the Nucleic Acid Rapid Test reagents used for the current major epidemic strains to avoid off-target misses.
The testing capability validation by the Chinese Center for Disease Control and Prevention shows that there is no difference in the sensitivity and precision of the detection of SARS-CoV-2 and its variants Alpha (B.1.1.7), Gamma (B.1.351) and Delta (B.1.617.2) by the products of several domestic Nucleic Acid Rapid Test Kit manufacturers, and the above variants can be detected without No off-target misses were observed.
