IHU Variant Not Concerning, Says WHO

IHU variant
Source: Freepik

A new coronavirus strain, called the IHU variant, has now emerged in France and contains 46 mutations.

In mid-November of last year, a man in Southern France tested positive for coronavirus. He had recently returned from a trip to Cameroon and had developed mild respiratory symptoms a day earlier. However, what made his case strange was that the virus in his sample did not have mutations similar to the then-dominant Delta variant. Health officials then conducted genome sequencing on samples from eight coronavirus-positive patients living in the same geographical area as the first case. These also showed similar mutations as the first sample. Further genome analysis of the samples led researchers to create a new Pangolin lineage for the strain. The new variant, named B.1.640.2, is nicknamed ‘IHU’ after the Institut Hospitalier Universitaire in Marseilles where it was identified. According to experts, it is a sister strain of the B.1.6.40 variant that the World Health Organization (WHO) has currently designated a ‘Variant Under Monitoring‘.

Subsequent detection… of three mutations in the spike gene to screen for variants… did not correspond to the pattern of the Delta variant involved in almost all SARS-CoV-2 infections at that time.

study author

More Mutations Than Omicron

Recently, a preprint study reported a detailed analysis of the new variant. According to the results, IHU contains a total of 46 mutations, more than the highly transmissible Omicron. Furthermore, it possessed multiple mutations in the spike protein; the most concerning of which was the N501Y and E484K. The N501Y mutation had previously appeared in the Alpha variant and is believed to increase transmissibility. Whereas the E484K mutation makes the strain resistant to vaccines.

These data are another example of the unpredictability of the emergence of SARS-CoV-2 variants, and of their introduction in a given geographical area from abroad.

study authors

Despite the multiple mutations, health officials believe there is nothing to worry about. WHO’s COVID incident manager, Abdi Mahmud said the variant ‘had a lot of chances to pick up’ but has not spread at a rate that’s alarming. Only 12 cases have come forward since last year. Moreover, cases have not occurred outside of France as yet. However, the low frequency of genomic sequencing can also be to blame for the low number of cases.

Authorities in France and neighbouring countries continue to monitor for the new variant. 


Colson, Philippe, et al. “Emergence in Southern France of a New SARS-COV-2 Variant of Probably Cameroonian Origin Harbouring Both Substitutions n501y and e484k in the Spike Protein.” 2021, doi:10.1101/2021.12.24.21268174.


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