The IHU variant of the coronavirus was first detected in Marseilles back in early November and was first traced back to a person who had just returned from a trip to Cameroon.
The origins of IHU
The southern French strain first infected a cluster of 12 people, all of which were linked back to 'the index case—' the first sequenced case identified at the heart of a cluster. This strain is currently still in circulation.
The strain has been identified in 19 countries so far—17 cases in Germany and 19 in the UK. However, it has not been able to move rapidly enough to be considered a 'variant of concern' by the WHO.
How contagious is IHU?
IHU, or B.1.640, was at one point placed under the category of a variant under monitoring when it first emerged. Though this variant has a total of 46 mutations, including some located in its spike protein—that which allows the virus to enter human cells—it is simply not as transmissible as other variants as observed with Omicron and Delta.
It has also been theorised that the number of mutations present in said variant isn't as effective in entering the human body, which would explain why it hasn't made much of an impact. However, more research will be needed to be able to give a clearer answer as to why this variant has not spread as rapidly.
As it stands currently, the last known sequenced case was detected on 25 December and hasn't been entered into any global databases that track transmissibility rates since. Tom Peacock, a virologist at Imperial College said:
[The IHU variant] is not one worth worrying about too much. This virus has had a decent chance to cause trouble but never really materialised.