SARS-CoV-2 JN.1 variant: a short review

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a single-stranded, positive-sense RNA virus. The SARS-CoV-2 virus is evolving continuously, and many variants have been detected over the last few years. SARS-CoV-2, as an RNA virus, is more prone to mutating. The continuous evolution of the SARS-CoV-2 virus is due to genetic mutation and recombination during the genomic replication process. Recombination is a naturally occurring phenomenon in which two distinct viral lineages simultaneously infect the same cellular entity in an individual. The evolution rate depends on the rate of mutation. The rate of mutation is variable among the RNA viruses, with the SARS-CoV-2 virus exhibiting a lower rate of mutation than other RNA viruses. The novel 3′-to-5′ exoribonuclease proofreading machinery is responsible for a lower rate of mutation. Infection due to the SARS-CoV-2, influenza, and respiratory syncytial virus has been reported from around the world during the same period of fall and winter, resulting in a “tripledemic.” The JN.1 variant, which evolved from the predecessor, the omicron variant BA.2.86, is currently the most dominant globally. The impact of the JN.1 variant on transmissibility, disease severity, immune evasion, and diagnostic and therapeutic escape will be discussed.