The covid-19 variant JN.1 may have been able to evade antibodies and spread globally due to one critical mutation to its spike protein
By Carissa Wong
9 August 2024
JN.1 spread widely despite many people being vaccinated and having previous covid-19 infections
Debarchan Chatterjee/NurPhoto/Shutterstock
One mutation may have been crucial to the covid-19 variant JN.1 spreading rapidly around the world last year, demonstrating how quickly the virus can adapt.
“A single mutation in JN.1 was key for it to evade the antibody response, and that’s why it was able to spread globally,” says Emanuele Andreano at the Toscana Life Sciences Foundation in Italy.
JN.1, a subvariant of the omicron variant, was first identified in Luxembourg in August 2023. At the end of January, it accounted for 88 per cent, 85 per cent and 77 per cent of the recorded infections in the US, UK and Australia, respectively. Its predecessor, BA.2.86, never accounted for more than 5 per cent of known global infections.
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With JN.1 and its descendants remaining the most reported covid-19 variants globally, Andreano and his colleagues wanted to investigate how it spread so widely. Genetic sequencing previously pointed to an additional mutation compared with BA.2.86 in its spike protein, which the virus uses to infect host cells.
To learn more, Andreano and his colleagues analysed 899 types of antibodies from blood samples previously collected from 14 people, all of whom had received two or three doses of an mRNA covid-19 vaccine and had confirmed infections with prior variants.