Fast Evolution Of SARS-CoV-2 Variant JN1
The cruel memories of Covid -19 catastrophe will never be forgotten. With that, every new variant causes a `shudder in our spine’. The new variant(JN1) was first identified is Luxembourg, which is a descendant of the Pirola variant (BA.2.86), which itself stems from the Omicron sub-variant. It carries mutations which enhance its capability of `Immune escaping capabilities which is also reported by the CDC, Atlanta, USA. In the USA, at present 15-29 per cent of cases of Covid are caused by this variant. Fortunately, the disease is mild causing fever, sore throat, cough, body aches etc. The first case in India was reported from Kerala in an elderly woman with mild symptoms.
Historically, the first case of Covid was also detected in Kerala in the beginning of the Pandemic.
This elegant research study published on 15 December in the journal Lancet has illustrated the biotechnological basis by which JN1 virus evades (escapes) pre-existing immunity. However, in my thinking, there is no need for any kind of panic. Corona, an RNA virus, is notorious for mutations and with enhanced facilities of detection and characterization, more and more variants are periodically detected. This particular variant (JN1) is fortunately causing mild illness. However, as a matter of extreme caution, it is advised that `Covid appropriate behaviour’ should be practiced, especially by the susceptible populations of which hand hygiene (and mask by susceptible populations) is most important. Creating panic, at present may confuse, as there is a high incidence of cough, sore throat and other viral-like illnesses in Delhi NCR attributable to air pollution. Having said that susceptible populations with influenza-like illness ( fever, body ache sore throat, running nose, cough) may be tested for Covid with RTPCR or home testing by a Kit. For susceptible populations, it is best to avoid going to crowded. With high levels of air pollution, it is best to use N 95 mask which will protect against both Covid and adverse effects of pollution.
Salient Features
• The SARS-CoV-2 variant BA.2.86, which was quickly designated as a variant under monitoring after its emergence, has attracted global attention. It showed remarkably high ACE2 binding affinity.
• With just one additional receptor binding domain mutation (L455S) compared to its predecessor BA.2.86, the JN.1 variant rapidly became predominant in France . JN.1 displayed significantly enhanced immune escape compared with BA.2.86
• JN.1, by inheriting BA.2.86’s antigenic diversity, rapidly achieved extensive resistance across receptor binding domain class 1, 2, and 3 antibodies, 1 and showed higher immune evasion compared with BA.2.86 and other resistant strain
• Such strains could survive and transmit at low levels since their antigenic difference would allow them to target distinct populations compared with dominant strains and have the potential to quickly accumulate highly immune-evasive mutations
The author is Chairman, PSRI Institute of Pulmonary, Critical care and Sleep Medicine. Formerly, Professor and Head, Dept of Pulmonary, Critical care and Sleep Med Medicine, AIIMS, N Delhi
