SARS-CoV-2 variant emergence patterns throughout Alaska
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Since the onset of the coronavirus illness 2019 (COVID-19) pandemic, the genomic evolution of the extreme acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been broadly reported. Owing to genomic mutations, a number of SARS-CoV-2 variants have emerged and have been categorized as variants of concern (VOC) and variants of curiosity (VOI) by the World Health Organization (WHO) in accordance with their transmissibility, functionality to flee immune responses, and virulence. 

Study: A repeat sample of founder occasions for SARS-CoV-2 variants in Alaska. Image Credit: hyotographics /


Certain SARS-CoV-2 variants, particularly VOCs, have diminished the efficacy of accessible COVID-19 vaccines; thus, their circulation has elevated an infection charges globally. Similar to many areas internationally, Alaska skilled an elevated unfold of the SARS-CoV-2 Alpha (B.1.1.7) variant between the top of 2020 and early 2021. Alaska is taken into account a definite state inside the United States because of its giant measurement, uniquely numerous and dense inhabitants, and bodily distance from the contiguous United States.

Unlike different contiguous areas of the United States, Alaska was predominantly impacted by the B.1.1.519 lineage all through early 2021. During the identical interval, researchers noticed 77.9% of B.1.1.51 prevalence in Alaska as in comparison with 4.9% all through different contiguous U.S. states. This discovering signifies a B.1.1.519 founder occasion in Alaska.

Although initially Alaska and different U.S. states exhibited differential patterns related to dominantly circulating SARS-CoV-2 variants, each areas ultimately exhibited an identical sample through the Delta- and Omicron-dominant waves. Although the incidence of the Omicron variant in Alaska and different U.S. states was related, the emergence of sublineages inside the bigger variant classification was completely different.

Several research have indicated that Omicron sublineages exhibit a major divergence that impacts immune responses. These sublineages current the chance of recurrent infections, which may extend the COVID-19 pandemic. 

About the examine

A brand new examine printed on the medRxiv* preprint server assesses the sample of SARS-CoV-2 variant emergence throughout Alaska. The Omicron sublineage reported within the present examine, BA.2.3, accommodates a number of mutations together with L140F within the open studying body (ORF3a) protein, in addition to A2909V in ORF1a. These mutations are accountable for the variant’s capability to evade immune responses and elevated replication fee.

In this examine, researchers obtained genomic sequences from the Global Initiative on Sharing All Influenza Data (GISAID) to check the sample of incidence and transmission of the Omicron sublineage BA.2.3, which is often known as B.1.1.529.2.3, in Alaska. Herein, the scientists in contrast this sample with the SARS-CoV-2 emergence sample related to the ‘the Lower’, which refers to states inside the contiguous U.S., in addition to different main U.S. states together with New York, California, and Washington.

Study findings

The next prevalence of the Omicron lineage BA.2.3 was reported in Alaska as in comparison with the Lower. To examine the emergence sample, scientists decided the date of first detection and incidence of BA.2.3 in each areas.

To this finish, the researchers noticed that the Omicron variant was first reported from the Anchorage-Mat Su area of Alaska, which is a densely populated space on December 19, 2021. Soon after its incidence, this variant changed the pre-existing Delta variant and have become the dominantly circulating pressure in each Alaska and the Lower.

The Omicron sublineage BA.1.1 prevailed in each Alaska (66.3%) and the Lower (67.2%). During this time, the Omicron sublineage BA.2 was detected in some elements of the U.S.

By January 16, 2022, though the Lower area exhibited a 0.2% of prevalence of BA.2, Alaska confirmed no such prevalence. During the identical interval, Alaska reported a 2.7% incidence of the sublineage BA.2.3 (2.7%), which is akin to the 0.1% prevalence reported within the Lower.

The % of sequences by week (estimated prevalence) coloured by SARS-CoV-2 lineages detected from 2021-11-28 to 2022-04-03 in (A) Alaska and (B) the Lower 48. BA lineages of Omicron besides BA.1.1, BA.2, and BA.2.3 are aggregated into B.1.1.529. BA.2 consists of all sublineages of BA.2 detected besides BA.2.3.

Soon after, BA.2.3 circumstances considerably elevated in Alaska to 45.3% as in comparison with the Lower (6.1%), New York (5.5%), Washington (17.6%), and California (16.2%). This distinction in prevalence highlights the divergent patterns of BA.2.3. 

The % of sequences by week (estimated prevalence) belonging to BA.2.3 coloured by states together with Alaska, California, New York, and Washington detected from 2021-11-28 to 2022-04-03.

The composition of SARS-CoV-2 lineages inside Alaska and the Lower contained differential units of mutation. The absence of different lineages in Alaska allowed the founding of BA.2.3 within the inhabitants. Spatiotemporal variation within the incidence and transmission of SARS-CoV-2 lineages was recognized throughout a large geographical space. 

Alaska accommodates six financial areas outlined by the U.S. Department of Labor and Workforce Development, which included the Southwest, Anchorage-Mat Su, Gulf Coast, Interior, Southeast, and Northern areas. Model research have proven that among the many financial areas of Alaska, the Gulf Coast recorded the earliest detection of the BA.2.3., which finally turned the dominant circulating pressure of the area.


In the present examine, the GISAID repository was used to exhibit the distinct emergence and transmission patterns of the SARS-CoV-2 Omicron BA.2.3 sublineage in Alaska as in comparison with the Lower and different areas of the U.S. Herein, researchers report the potential ancestral origins of BA.2.3 circumstances in Alaska and its unfold throughout the financial area of the state. The distinctive location of Alaska would possibly affect the emergence of distinct SARS-CoV-2 variants.

*Important discover

medRxiv publishes preliminary scientific reviews that aren’t peer-reviewed and, subsequently, shouldn’t be considered conclusive, information scientific follow/health-related habits, or handled as established data.

Journal reference:

  • Haan, J. T., Smith, L. Ok., DeRonde, S., et al. (2022) A repeat sample of founder occasions for SARS-CoV-2 variants in Alaska. medRxiv. doi: 10.1101/2022.05.25.22275610. material/10.1101/2022.05.25.22275610v1.

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