Changes to virus taxonomy and the ICTV Statutes ratified by the International Committee on Taxonomy of Viruses (2023) (original) (raw)

. Author manuscript; available in PMC: 2024 Feb 12.

Abstract

This article reports changes to virus taxonomy and taxon nomenclature that were approved and ratified by the International Committee on Taxonomy of Viruses (ICTV) in April 2023. The entire ICTV membership was invited to vote on 174 taxonomic proposals that had been approved by the ICTV Executive Committee in July 2022, as well as a proposed revision of the ICTV Statutes. All proposals and the revised ICTV Statutes were approved by a majority of the voting membership. Of note, the ICTV continued the process of renaming existing species in accordance with the recently mandated binomial format and included gene transfer agents (GTAs) in the classification framework by classifying them as viriforms. In total, one class, seven orders, 31 families, 214 genera, and 858 species were created.

Introduction

Changes to virus taxonomy (the universal scheme of virus classification of the International Committee on Taxonomy of Viruses [ICTV]) take place annually and are the result of a multi-stage process. In accordance with the ICTV Statutes (https://ictv.global/about/statutes), proposals are submitted to the ICTV Executive Committee (EC) and undergo a review process that involves input from the ICTV Study Groups (SGs) and Subcommittees (SCs), other interested virologists, and the EC. After final approval by the EC, proposals are placed on the ICTV website (https://ictv.global) for viewing by the full ICTV membership, which ratifies them by online voting [1].

The latest set of proposals approved by the EC was made available on the ICTV website in February 2023 (see https://ictv.global/files/proposals/approved for all proposals combined into a single zip file, and use the links provided in the References to access individual proposals). A list of proposals was emailed on March 8, 2023, to the 185 members of the ICTV – the EC Members, SC Members (including the SG chairs and co-chairs), ICTV Life Members, and ICTV National Representatives. Members were then requested to vote on whether to ratify the taxonomic proposals. Voting closed on April 8, 2023.

Changes to virus taxonomy and the ICTV Statutes

All proposals [1–174] were ratified by ICTV members (72% of eligible voters), in every case receiving a majority of “yes” votes (99-100%). A summary of the taxonomy changes enacted by the proposals is provided in Table 1. The new class, orders, and families ratified in 2023 are listed in Table 2. Each proposal is cited and listed in the References to acknowledge the authors’ efforts and to provide links to the specific proposal on the ICTV website. These documents remain available for those who would like to see the details of the proposals.

Table 1.

Summary of taxonomic changes approved by the ICTV in 2023

Rank MSL #37 Totala New Abolished Moved Renamed MSL #38 Totalb
Realm 6 0 0 0 0 6
Subrealm 0 0 0 0 0 0
Kingdom 10 0 0 0 0 10
Subkingdom 0 0 0 0 0 0
Phylum 17 0 0 0 0 17
Subphylum 2 0 0 0 0 2
Class 39 1 0 0 0 40
Subclass 0 0 0 0 0 0
Order 65 7 0 0 0 72
Suborder 8 0 0 0 0 8
Family 233 31 0 1 1 264
Subfamily 168 14 0 1 0 182
Genus 2,606 214 2 15 12 2,818
Subgenus 84 0 0 0 0 84
Species 10,434 858 19 6 1,643 11,273

Table 2.

New classes, orders, and families ratified by the ICTV in 2023

Of note, a large number of proposals renamed existing species for compliance with the recently mandated binomial nomenclature format. As a result, 8,982 out of the current 11,273 species (80%) now have binomial names. The process will be concluded in 2023, with the remaining 2,291 species being renamed.

Another notable taxonomic change approved in this ratification was the inclusion of gene transfer agents (GTAs) in the classification scheme as viriforms [154].

A change to the ICTV Statutes was also ratified in the vote and approved in May 2023 by the Virology Division of the International Union of Microbiological Societies (IUMS), which is the parent organization of the ICTV. The new ICTV Statutes can be found at https://ictv.global/about/statutes. The purpose of the approved change was to specify a three-year cycle for the ICTV Plenary Meeting. As stated in the new text of Article 5.1: “Plenary Meetings of the full ICTV membership shall be held every three years. In the years when it coincides with the International Congresses of Virology (ICV) organized by the IUMS, the Plenary Meeting shall be held in conjunction with the ICV. Otherwise, the Plenary Meeting shall be held online no later than one month after the Executive Committee annual meeting”.

Conclusion

All proposals submitted for ratification were ratified by a majority vote of the ICTV, and the additions and changes to virus classification are now part of the official ICTV taxonomy. New ICTV Statutes are now in force as well. An up-to-date list of all approved taxa, which now includes 11,273 virus species, can be found on the ICTV website: See https://ictv.global/msl for the Master Species List (MSL) and https://ictv.global/vmr for the Virus Metadata Resource (VMR), the latter of which provides an exemplar virus isolate for each species along with the GenBank accession number of the isolate.

Acknowledgements

The authors thank Anya Crane (Integrated Research Facility at Fort Detrick, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fort Detrick, Frederick, MD, USA) for critically editing the manuscript.

Funding

F.M.Z. acknowledges financial support from Capes (Finance code 01), CNPq, and Fapemig. E.M.A. gratefully acknowledges funding by the U.K. Biotechnology and Biological Sciences Research Council (BBSRC); this research was funded in part by the BBSRC Institute Strategic Programme Gut Microbes and Health BB/R012490/1 and its constituent projects BBS/E/F/000PR10353 and BBS/E/F/000PR10356. B.E.D. is supported by the European Research Council (ERC) Consolidator grant 865694: DiversiPHI, the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy – EXC 2051 – Project-ID 390713860, and the Alexander von Humboldt Foundation in the context of an Alexander von Humboldt-Professorship funded by the German Federal Ministry of Education and Research. This work was supported in part through Laulima Government Solutions, LLC, prime contract with the US National Institute of Allergy and Infectious Diseases (NIAID) under Contract No. HHSN272201800013C. J.H.K. performed this work as an employee of Tunnell Government Services (TGS), a subcontractor of Laulima Government Solutions, LLC, under Contract No. HHSN272201800013C. A.R.M. is a Program Director at the U.S. National Science Foundation (NSF); the statements and opinions expressed herein are made in a personal capacity and do not constitute endorsement by NSF or the government of the United States. H.M.O. was supported by the University of Helsinki and Academy of Finland by funding for FIN-Struct and Instruct Centre FI, part of Biocenter Finland and Instruct – ERIC. D.L.R. is supported by the U.K. Medical Research Council (MC_UU_1201412). D.B.S. is supported by the Microbiology Society. S.S. acknowledges support from the Mississippi Agricultural and Forestry Experiment Station (MAFES), USDA-ARS project 58-6066-9-033 and the National Institute of Food and Agriculture, U.S. Department of Agriculture, Hatch Project, under Accession Number 1021494. E.J.L, D.M.D. and R.C.H were supported by the National Institute of Allergy and Infectious Diseases of the National Institutes of Health under Award Number U24AI162625. Except for Donald M. Dempsey, R. Curtis Hendrickson, and Donald B. Smith, the authors were members of the ICTV Executive Committee during the relevant period. The views and conclusions contained in this document are those of the authors and should not be interpreted as necessarily representing the official policies, either expressed or implied, of the US Department of Health and Human Services, or of the institutions and companies affiliated with the authors. The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of their affiliates, including the Centers for Disease Control and Prevention. For the purpose of open access, the authors have applied a Creative Commons Attribution (CC BY) licence to any author accepted manuscript version arising from this submission.

Footnotes

Conflict of interest The authors declare no conflicts of interest.

Ethical approval None of the work reported involved research on human participants or animals. All authors have contributed to this work and agreed to its publication.

Data availability

All Taxonomy Proposals and all other ICTV resources mentioned in this article are freely available at the ICTV website (http://www.ictv.global).

References

Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Data Availability Statement

All Taxonomy Proposals and all other ICTV resources mentioned in this article are freely available at the ICTV website (http://www.ictv.global).