Play Understanding the data and science behind JN.1 and the threat it poses free
The World Health Organization (WHO) late on Tuesday formally classified JN.1 as a Sars-CoV-2 variant of interest (not a variant of concern), after noticing a rapid spread around the world. Put simply, the WHO and other experts believe the global public health risk from it is low. But here is why it is still under watch.
1. ANOTHER EVOLUTIONARY LEAP
JN.1 has descended from BA.2.86, which in itself was distinct from the Omicron’s XBB family of descendants.
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The distance from XBB is significant because since Omicron displaced all past variants, there have only been a handful of its dominants: for instance, the BA.2 and BA.5. In other words, JN.1 now seems to be the new XBB, which in itself was the new BA.2 back in early 2023.
2. A KEY MUTATION
The characteristic mutation in JN.1 is L455S in the S protein. As the Sars-CoV-2 evolved over the years, it is the evolution in S protein that has been the key. This protein is what is responsible for hooking on to human cells and infecting them.
Lab studies by Japanese researchers found that L455S can make the coronavirus more resistant to antibodies generated on the past versions of the virus.
3. IMMUNE RESISTANCE
It is this immune resistance that has been the main feature of JN.1, a reason why it now accounts for nearly 38% of all sequences submitted to the global GISAID repository in the week ending December 10.
4. FLU SEASON
The WHO pointed out another simpler explanation: the onset of winter in the Northern Hemisphere causes a spike in respiratory infections as people spend more time indoors. The JN.1 could, therefore, increase the burden of respiratory infections in what is a peak flu season.
Cases rising, but still incredibly low
According to the bulletin issued by the government on Wednesday, India reported 614 new Covid cases. This takes the seven-day average of new cases to 344, the highest since the end of May. It is quite apparent that there has been an increase in Covid-19 cases.
However, context is very important here. The current case rate (the seven-day average) is rising, but is still tiny when seen alongside India’s population, the previous waves of the pandemic, and even numbers that we have seen this year – in late April this year, this number jumped to around 10,000 likely due to the XBB.1.16 Omicron variant.
In comparison, the three full-blown waves of Covid-19 peaked at weekly averages of 93,617 (week ending September 16, 2020), 391,819 (week ending May 9, 2021), and 312,180 (week ending ending January 25, 2022).