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EDITORIAL |
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Year : 2022 | Volume
: 2
| Issue : 1 | Page : 1 |
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Variants of concern: A real cause of worry?
AR Paramez
Editorial Team, Journal of Adv Lung Health
Date of Submission | 28-Nov-2021 |
Date of Decision | 28-Nov-2021 |
Date of Acceptance | 29-Nov-2021 |
Date of Web Publication | 17-Jan-2022 |
Correspondence Address: Dr. A R Paramez Lisie Hospital, Kochi, Kerala
 Source of Support: None, Conflict of Interest: None
DOI: 10.4103/jalh.jalh_25_21
How to cite this article: Paramez A R. Variants of concern: A real cause of worry?. J Adv Lung Health 2022;2:1 |
SARS Coronavirus-2 an enveloped positive-stranded RNA virus that causes COVID-19 is a betacorona virus as indicated by full-genome sequencing. Early in the pandemic, a study that monitored amino acid changes in the spike protein of SARS-CoV-2 included in a large sequence database identified a glycine for aspartic acid substitution (D614G) that became the dominant polymorphism globally over time. Viruses bearing the G614 polymorphism demonstrate higher levels of infectious virus in the respiratory tract, enhanced binding to ACE-2, and accelerated replication and increased transmissibility compared with the D614 polymorphism. Different variants occur due to the mutation in the genomic sequence of the virus.
The Technical Advisory Group on SARS-CoV-2 Virus Evolution is an independent group of experts that periodically monitors and evaluates the evolution of SARS-CoV-2 and assesses if specific mutations and combinations of mutations alter the behavior of the virus. “Variants of Concern” (VOC) have evidence of an increase in transmissibility, higher risk of severe disease, a significant reduction in neutralization by antibodies generated during previous infection or vaccination, diagnostic detection failures, or reduced effectiveness of treatments or vaccines. Various lineages of SARS- CoV2 had been considered as VOC-like alpha (B.1.1.7), beta (B.1.351), gamma (P. 1), and delta (B.1.617.2).[1] Till date, the biggest impact on case burden, infectivity, morbidity, and mortality was due to the delta variant which was detected in India in late 2020 and spread all over the world.
The new variant “Omicron” (B.1.1.529) variant was first reported to the WHO from South Africa on November 24, 2021.[2] After the case numbers secondary to delta variant decreased, in recent weeks, infections have increased steeply, coinciding with the detection of B.1.1.529 variant. The first known confirmed B.1.1.529 infection was from a specimen collected on November 09, 2021. This variant has a large number of mutations, some of which are concerning. Preliminary evidence suggests an increased risk of reinfection with this variant, as compared to other VOCs. Current SARS-CoV-2 polymerase chain reaction (PCR) diagnostics continue to detect this variant. In PCR tests, one of the three target genes is not detected (called S gene dropout or S gene target failure) and this test can therefore be used as marker for this variant, pending sequencing confirmation-rapid identification may be possible.
Unless the spread of infection is controlled, new variants are expected to occur in future also. Hence, it is imperative that standard infection control practices and proven public health and social measures such as wearing well-fitting masks, hand hygiene, physical distancing, improving the ventilation of indoor spaces, avoiding crowded spaces, and getting vaccinated; are to be adhered by everyone irrespective of their vaccination status till the pandemic is under control. India should enhance surveillance and sequencing efforts[3] to better understand circulating SARS-CoV-2 variants, submit complete genome sequences and available databases, report initial cases/clusters associated with VOC infection to the WHO. The emphasis on vaccination among populations irrespective of their nationality, religion, caste, socioeconomic status, etc., should not be forgotten.
No one is safe until everyone is safe.
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