#16,968
Just over 6 months ago, in mid-December of 2020, the first COVID vaccines were rolling off the production line and there was suddenly optimism the tide against the pandemic was about to turn. Then, on December 14th, the UK Health Secretary Announced A New COVID Variant (B.1.1.7) had been detected in Southern England.
Barely a week later, a second variant was announced (see Matt Hancock Announces First Detection Of South African COVID Variant (501Y.V2) In The UK), and suddenly the UK was going back into lockdown.
Since then, the number of Variants of Concern (VOCs) and Variants of Interest (VOIs) has grown into the double digits, as large variant driven epidemics swept across Brazil and India. A quick end to the pandemic seems no longer assured, as some of these variants appeared to be more transmissible, or able to evade existing immunity, or both.
Six months later, new variants continue to appear, and what we know about many of the existing variants is limited. Some seem more susceptible to the current vaccine than others, but it is far from clear how much of a threat they pose.
Today the ECDC has published a technical document outlining a review protocol for investigating current (and future) variants, with the aim of producing their first review results in June 2021.
Note: Although published today, the cut off date of this document appears to have been May 7th, as a newly recognized VOC (B.1.617.x) is not addressed.
While the details of this investigation are probably of greatest interest to public health officials, I've reproduced the executive summary below. Those who want to take a deeper dive will want to follow the link and download the full 16-page PDF.
Public health impact of SARS-CoV-2 variants of concern: scoping review protocol
Technical report
18 May 2021
Several SARS-CoV-2 variants have been identified. Some of these variants have mutations that (alone or in combination) may provide the virus with a selective advantage, such as increased transmissibility or the ability to evade the host immune response, or cause possible changes in pathogenicity, thus increasing disease severity.
Executive summary
On 25 February 2021, the World Health Organization (WHO) proposed the following working definitions to differentiate SARS-CoV-2 variants of the greatest public health relevance:
Variant of interest (VOI) is phenotypically changed compared to a reference isolate or has a genome with mutations that lead to amino acid changes associated with established or suspected phenotypic implications; AND has been identified to cause community transmission/multiple COVID-19 cases/clusters, or has been detected in multiple countries; OR is otherwise assessed to be a VOI by WHO in consultation with the WHO SARS-CoV-2 Virus Evolution Working Group [1].
Variant of concern (VOC) is a VOI that, through a comparative assessment, has been demonstrated to be associated with:
− Increase in transmissibility or detrimental change in COVID-19 epidemiology; AND/OR− Increase in virulence or change in clinical disease presentation; AND/OR− Decrease in effectiveness of public health and social measures or available diagnostics, vaccines, therapeutics; AND/OR− is assessed to be a VOC by WHO in consultation with the WHO SARS-CoV-2 Virus Evolution Working Group [1].
As of 7 May 2021, the following SARS-CoV-2 VOCs have been identified:The potential public health implications of these VOCs need to be understood and assessed, since their increased circulation may affect overall prevention and control strategies employed by ECDC and European Union/ European Economic Area (EU/EEA) countries.
- Variant B.1.1.7, first reported by the United Kingdom on 14 December 2020 [2], is defined by multiple spike protein changes (deletion 69-70, deletion 144, amino acid change N501Y, A570D, D614G, P681H, T716I, S982A, D1118H) [3], as well as by mutations in other genomic regions [4]. This VOC belongs to Nextstrain clade 20B [5,6], GISAID clade GR [7,8] and PANGO lineage B.1.1.7 [9,10].
- Variant B.1.1.7 with an additional mutation (E484K) is also designated as a variant of concern.
- Variant B.1.351, first reported in South Africa on 18 December 2020 [2], is defined by multiple spike protein changes (amino acid change D80A, D215G, D614G, E484K, K417N, N501Y, and A701V) [11]. This VOC belongs to Nextstrain clade 20C [5,6], GISAID clade GH [7,8], and PANGO lineage B.1.351 [9,10].
- Variant P.1, first reported by Japan in returning travellers from Brazil, and later in Brazil, has 11 amino acid changes in the spike protein compared to its ancestral lineage B.1.1.28, three of which are located in the receptor-binding domain. Spike protein changes for the variant are L18F, T20N, P26S, D138Y, R190S, K417T, E484K, N501Y, H655Y and T1027I [12]. This VOC belongs to Nextstrain clade 20B [5,6], GISAID clade GR [7,8] and PANGO lineage P.1. [9,10].
As a result, ECDC will conduct a scoping review on SARS-CoV-2 VOCs, with the purpose of identifying relevant emerging data that could inform ECDC’s scientific guidance and risk assessments.
Public health impact of SARS-CoV-2 variants of concern: scoping review protocol - EN - [PDF-505.21 KB]
While B.1.617.x was not specifically addressed in this review (but will presumably be included in this study), the ECDC did publish a Threat Assessment Brief On COVID Variant B.1.617.x last week.
While this may be the ECDC's first major review of COVID variants, unless the virus can be brought under better control around the globe, the odds suggest it won't be their last.
