Overnight the CDC updated their COVID Variant map and case count, raising the number of lab confirmed (B.1.1.7, B.1.351 & P.1) variants to nearly 5,800 across all 50 states. Given the limits of genomic sequencing, and the inevitable delays in reporting, these numbers likely only represent a small fraction of the total number of cases in the nation.
Until this week, the CDC has been reporting almost exclusively on the `big 3' variant concerns; B1.1.7 (aka `UK' variant), B.1.351 (aka `South Africa' variant,) and P.1 (aka `Brazil' variant). By contrast, the UK now has 10 VUIs (Variants Under Investigation) or VOC's (Variants of Concern) on their list.Once again, Florida leads the nation with 882 B.1.1.7 variants, along with 21 P.1 and 9 B.1.351 variants. Genomic sequencing rates varies widely across the nation, and so states with low numbers may still have a significant number of undetected cases.
Earlier this week the CDC announced the creation of 3 classes of variants (VOI, VOC, VHC), and included 5 more emerging variants on their list.
Additionally, the CDC has classified 3 other variants as VOIs (Variants of Interest). These include the P.2 variant from Brazil, and the B.1.526/B.1.525 variants detected in New York (see CIDRAP's New COVID-19 variants found in New York, California).
SARS-CoV-2 Variants
Updated Mar. 16, 2021Key Points:
Genetic variants of SARS-CoV-2 have been emerging and circulating around the world throughout the COVID-19 pandemic.
Viral mutations and variants in the United States are routinely monitored through sequence-based surveillance, laboratory studies, and epidemiological investigations.A US government interagency group developed a Variant Classification scheme that defines three classes of SARS-CoV-2 variants:
The two new VOCs (B.1.427/B.1.429), are the `California' variants which made headlines last January (see California DPH Statement On L452R Variant Linked To Several Large COVID Outbreaks), and appear to have moderate reduction in neutralization using convalescent and post-vaccination sera.
The B.1.1.7, B.1.351, P.1, B.1.427, and B.1.429 variants circulating in the United States are classified as variants of concernViruses constantly change through mutation. A variant has one or more mutations that differentiate it from other variants in circulation. As expected, multiple variants of SARS-CoV-2 have been documented in the United States and globally throughout this pandemic. To inform local outbreak investigations and understand national trends, scientists compare genetic differences between viruses to identify variants and how they are related to each other.
The CDC defines a VOC (Variant of Concern) as:
Variant of Concern
A variant for which there is evidence of an increase in transmissibility, more severe disease (increased hospitalizations or deaths), significant reduction in neutralization by antibodies generated during previous infection or vaccination, reduced effectiveness of treatments or vaccines, or diagnostic detection failures.
Possible attributes of a variant of concern:
In addition to the possible attributes of a variant of interestVariants of concern might require one or more appropriate public health actions, such as notification to WHO under the International Health Regulations, reporting to CDC, local or regional efforts to control spread, increased testing, or research to determine the effectiveness of vaccines and treatments against the variant. Based on the characteristics of the variant, additional considerations may include the development of new diagnostics or the modification of vaccines or treatments.
- Evidence of impact on diagnostics, treatments, and vaccines
- Widespread interference with diagnostic test targets
- Evidence of substantially increased resistance to one or more class of therapies
- Evidence of significant decreased neutralization by antibodies generated during previous infection or vaccination
- Evidence of reduced vaccine-induced protection from severe disease
- Evidence of increased transmissibility
- Evidence of increased disease severity
Current variants of concern in the United States that are being closely monitored and characterized by federal agencies are included in the table below. The table will be updated when a new variant of concern is identified.
The third class of variant (Variant of High Consequence) remains empty for now, but is reserved for emerging variants with an exceptional ability to undermine prevention efforts or medical countermeasures. Essentially, a game changer.
A variant of high consequence has clear evidence that prevention measures or medical countermeasures (MCMs) have significantly reduced effectiveness relative to previously circulating variants.Possible attributes of a variant of high consequence:In addition to the possible attributes of a variant of concern
- Impact on Medical Countermeasures (MCM)
- Demonstrated failure of diagnostics
- Evidence to suggest a significant reduction in vaccine effectiveness, a disproportionately high number of vaccine breakthrough cases, or very low vaccine-induced protection against severe disease
- Significantly reduced susceptibility to multiple Emergency Use Authorization (EUA) or approved therapeutics
- More severe clinical disease and increased hospitalizations
A variant of high consequence would require public health officials declare a PHEIC (if not already declared), reporting to CDC, an announcement of strategies to prevent or contain transmission, and recommendations to update treatments and vaccines.Currently there are no SARS-CoV-2 variants that rise to the level of high consequence.
Although COVID variants have been a part of the pandemic discussion for nearly a year (see COVID-19 & The `M' Word), it's only been a little over 90 days since the alarm was first raised in the UK about the more transmissible (and now believed to be more severe) B.1.1.7 variant.
As tired as we all are of dealing with this pandemic, the reality is viruses haven't survived and thrived for millions of years without developing significant survival skills.
Their ability to adapt, and evolve - particularly in the face of growing community immunity - makes them a formidable foe, even in this age of modern science and medicine. While the roll out of vaccines should dampen this pandemic's impact, these COVID variants pose a genuine challenge.
Whether any of these emerging variants will end up being the start of a new global viral offensive is unknown, but we should not automatically expect COVID to go quietly into the night.
