The Delta AY.29 sub-variant was first identified by Japanese researchers from Niigata University and the Japanese National Institute of Genetics.
The Japanese study team reported a new sub-lineage of the SARS-CoV-2 Delta variant called AY.29, which has C5239T and T5514C mutations.
The study team had investigated the monthly trend of AY.29 in Japan within 11,954 Delta variants downloaded on September 3, 2021. Among the total Japanese Delta variants, the AY.29 sub-lineage accounted for 88.4%.
In terms of monthly changes, the sequences became predominant in June, and accounted for 93.2% and 94.2% of the reported sequences in July and August, respectively. Furthermore, the number of Delta variants imported from abroad during the Tokyo 2020 Olympics and Paralympics (held in August 2021) was extremely low.
Therefore, the epidemic of the new Delta variant is attributable to a newly occurring mutation in Japan.
Their study findings were published on a preprint server and are currently being peer reviewed. https://www.medrxiv.org/content/10.1101/2021.09.20.21263869v2
To date there is not much information available about the significance and characteristics nor the protein functions of the mutations C5239T and T5514C (ORF1ab: 56 V1750A) that distinguishes the Delta AY.29 sub-variant.
Data from the study sh ows that the Delta AY.29 sub-variant must have emerged around April 2021 in Japan but only became predominant around June and then became more potent and dangerous around August 2021, causing an increase of disease severity, hospitalizations and deaths.
Characteristic mutations of AY.29
reference link : https://outbreak.info/situation-reports?pango=AY.29