JN.1 - A Game-Changing Shift in Covid-19. Why Does It Matter?

Since it was detected in August 2023, the JN.1 variant of COVID has spread widely. Its prevalence in Africa is poorly documented, but has become dominant around the world, driving the biggest COVID wave seen in many jurisdictions for at least the past year, write Suman Majumdar, Brendan Crabb, Emma Pakula and Stuart Turville for The Conversation. 

JN.1 is significant. First as a pathogen - it's a surprisingly new-look version of SARS-CoV-2 (the virus that causes COVID) and is rapidly displacing other circulating strains (omicron XBB).

It's also significant because of what it says about COVID's evolution. Normally, SARS-CoV-2 variants look quite similar to what was there before, accumulating just a few mutations at a time that give the virus a meaningful advantage over its parent.

There are two elements to its "severity": first if it is more "intrinsically" severe (worse illness with an infection in the absence of any immunity) and second if the virus has greater transmission, causing greater illness and deaths, simply because it infects more people. The latter is certainly the case with JN.1.