Context: Kerala has registered the first case of infection due to JN.1 variant of Sars-CoV-2 — the latest sub-variant of the virus that is behind a spike of infections in several countries across the world.
JN.1 variant of Sars-CoV-2
- The JN.1 sub-variant is a new sub-lineage of the BA.2.86 (also known as Pirola) — which itself is an off-shoot of the widely circulating Omicron variant of Sars-CoV-2.
- The JN.1 variant has been classified as a variant of interest by the World Health Organisation.
- Variants of Interest: Variants that, compared with earlier forms of the virus, are less effectively neutralised in labs by antibodies from infection or vaccination and have a potential to spread.
- Variants of Concern: Variants that result in increased transmission, severe disease leading to hospitalisation, and reduce effectiveness of vaccines.
SARS-CoV-2 Virus
- Coronavirus disease 2019 (COVID-19) is a highly contagious viral illness caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).
- SARS-CoV-2 is a novel beta coronavirus belonging to the same subgenus as the severe acute respiratory syndrome Coronavirus (SARS-CoV) and Middle East Respiratory Syndrome Coronavirus (MERS-CoV).
- It was first identified in December 2019 in Wuhan, China, and then caused a global pandemic leading to the COVID-19 pandemic.
- Coronaviruses are positive-stranded RNA viruses with a crown-like appearance due to the presence of spike glycoproteins on the envelope.
- Like other RNA viruses, SARS-CoV-2, while adapting to their new human hosts, is prone to genetic evolution with the development of mutations over time. This results in mutant variants that may have different characteristics than its ancestral strains.
- Origin: Although the origin of SARS-CoV-2 is currently unknown, it is widely postulated to have originated from an animal, implicating a zoonotic transmission.
- Transmission: Exposure to respiratory droplets carrying the infectious virus from close contact or droplet transmission from presymptomatic, asymptomatic, or symptomatic individuals.
What is mutation of a virus?
- Mutation of a virus, in simple words, means that it is acquiring genetic changes. Mutations are errors in the replication of the virus’s genetic code.
- During replication, the virus copies its genetic material (usually RNA or DNA) to create new copies of itself.
- Sometimes, mistakes happen during this copying process. These mistakes can lead to changes in the virus's genetic code, which are called mutations.
Why do Viruses mutate?
Effects of mutations on the virus
- Neutral: This means that they have no effect on the virus's ability to replicate or cause disease.
- Potent: These mutations can make the virus more replicative or more virulent. E.g., Delta variant of COVID-19.
- Less Potent: Some mutations could make the virus less replicative or less infectious. In some cases, these mutations can even make the virus unable to replicate at all.