2023-05-03 ロスアラモス国立研究所(LANL)
◆この研究は、過去の変異株移行が地球上でどのように異なるかを調べ、新しい変異株の速度と完全性に影響を与える要因を特定するのに役立ちます。特に、高い免疫力は、前回のピークからの時間が短く、以前の感染が高い場所ほど、新しい変異株の移行が遅くなる傾向があることがわかりました。
◆また、DeltaおよびMu変異株以降、高いワクチン接種率が新しい変異株の移行を遅らせたことが示されましたが、Omicron変異株ではそれが減少していることが示唆されています。
<関連情報>
- https://discover.lanl.gov/news/covid-variant/
- https://www.thelancet.com/journals/ebiom/article/PIIS2352-3964(23)00099-3/fulltext
SARS-CoV-2のバリアント遷移ダイナミクスは、ワクチン接種率、共存する変異株数、回復期免疫と関連する SARS-CoV-2 variant transition dynamics are associated with vaccination rates, number of co-circulating variants, and convalescent immunity
Lauren J. Beesley,Kelly R. Moran,Kshitij Wagh,Lauren A. Castro,James Theiler,Hyejin Yoon,Will Fischer,Nick W. Hengartner,Bette Korber,Sara Y. Del Valle
eBioMedicine Published:March 31, 2023
DOI:https://doi.org/10.1016/j.ebiom.2023.104534
Summary
Background
Throughout the COVID-19 pandemic, the SARS-CoV-2 virus has continued to evolve, with new variants outcompeting existing variants and often leading to different dynamics of disease spread.
Methods
In this paper, we performed a retrospective analysis using longitudinal sequencing data to characterize differences in the speed, calendar timing, and magnitude of 16 SARS-CoV-2 variant waves/transitions for 230 countries and sub-country regions, between October 2020 and January 2023. We then clustered geographic locations in terms of their variant behavior across several Omicron variants, allowing us to identify groups of locations exhibiting similar variant transitions. Finally, we explored relationships between heterogeneity in these variant waves and time-varying factors, including vaccination status of the population, governmental policy, and the number of variants in simultaneous competition.
Findings
This work demonstrates associations between the behavior of an emerging variant and the number of co-circulating variants as well as the demographic context of the population. We also observed an association between high vaccination rates and variant transition dynamics prior to the Mu and Delta variant transitions.
Interpretation
These results suggest the behavior of an emergent variant may be sensitive to the immunologic and demographic context of its location. Additionally, this work represents the most comprehensive characterization of variant transitions globally to date.
Funding
Laboratory Directed Research and Development (LDRD), Los Alamos National Laboratory.
