The VOI 20C / H655Y (lineage B.1.616) initially detected in Lannion, in Brittany, was classified as variant to follow on 03/14/2021. Among the mutations and deletions carried by this VOI, several are found in one or more VOCs and VOIs, and could lead to increased transmissibility (H655Y in particular), post-vaccination or post-infection immune escape or even lower efficacy monoclonal antibody treatments (Y144- deletion, D215G and V483A mutations).
However, according to analyzes carried out by the CNR using sera from vaccinated subjects, infected subjects, or antibodies monoclonal, the data available at this stage do not show significant escape of the variant 20C / 655Y on neutralization. As of 05/04/2021, 42 confirmed cases of infection with the 20C / 655Y variant have been reported in France, including 39 in Brittany and 3 in other regions in people linked to the zone of circulation of the virus in Brittany (made up of several urban communities around Lannion, Guingamp, Saint- Brieuc, Paimpol). Eighteen deaths (43%) were reported, mostly in the elderly (age median 84 years) or with co-morbidities.
The high lethality associated with this variant is probably related to a bias in the identification of cases in which this variant was detected, most often from deep samples (generally more serious), but additional investigations are carried out to characterize the impact of this variant in terms of severity. The majority of confirmed cases are related to transmission chains in healthcare establishments in this geographical area (CH de Guingamp, de Lannion, de Paimpol).