A range of SARS-CoV-2 variants has emerged across the world since the COVID-19 pandemic began. Most attention has been on fast-spreading variants recently identified in the UK, South Africa, and Brazil. Scientists suspect that the variants’ particular patterns of mutations have the potential to affect their transmissibility, virulence, and/or ability to evade parts of the immune system. The latter could make people with vaccine-induced or natural immunity to SARS-CoV-2 vulnerable to becoming reinfected with novel variants, and these possible effects remain under investigation.
There are a handful of other variants—typically with fewer eye-catching mutations—that researchers are also keeping a close watch on, notes molecular epidemiologist Emma Hodcroft of the University of Bern in Switzerland. Making matters confusing, scientists can’t agree on a standardized naming system for new variants, causing what one researcher has called a “bloody mess” of nomenclature.
Here The Scientist compiles a summary of some noteworthy variants recently associated with rapid spread that US researchers are currently monitoring.
Name(s) | Distribution | Notable mutations | Potential effects on transmissibility, virulence, and immune escape | B.1.1.7, 20I/501Y.V1, VOC202012/01 | First identified in late December in the UK, it has spread to 62 countries in Europe, Asia, the US, and elsewhere. | 17 recent mutations, including N501Y, P681H, HV 69–70 deletion, and four more on the spike protein; the ORF8 Q27stop mutation outside the spike protein | • Thought to have greater than 40 percent increased transmissibility • Increased virulence suggested but remains unresolved • Little concern around current vaccine efficacy | B.1.351, 20C/501Y.V2 | Identified in late December in South Africa and now spotted in Africa, Europe, Asia, and Australia | 21 mutations, including N501Y, E484K, and K417N on the spike protein, and ORF1b deletion outside the spike protein | • Suggested to have heightened transmissibility • No evidence of increased virulence • In vitro studies suggest a potential for immune escape following natural infections and a small effect on the potency of vaccine-induced antibodies | P.1, 20J/501Y.V3 | Discovered in travelers from Brazil during screening at a Japanese airport in January; now known to widely circulate in Brazil’s Amazonas state and also observed in the Faroe Islands, South Korea, and the US | 17 amino acid changes, including N501Y, E484K, and K417N on the spike protein; ORF1b deletion outside the spike protein | • Effect on transmissibility and/or virulence unknown • Anecdotes of reinfections reported, but potential for immune evasion remains unresolved | COH.20G/501Y | Two cases of the N501Y mutation have been detected in Columbus, Ohio, since late December, and in other US states since | N501Y, located in the virus’s spike protein. It lacks most other mutations present in the B.1.1.7 variant identified in the UK. | • No evidence yet of altered transmissibility, virulence, and/or immune evasion | S Q677H, sometimes called “Midwest” variant | Viruses containing the S Q677H mutation have recently become frequent in samples analyzed during December and January in Ohio, and have also been found in multiple Midwest states | Q677H mutation on the spike protein, A85S on the M protein, and D377Y on the nucleocapsid protein | • So far, no evidence of altered transmissibility, virulence, and/or immune evasion | L452R, B1429 | The L452R mutation itself was observed in the US and Europe last year. In January 2021, it rose rapidly in frequency in multiple California counties. | L452R mutation, located on the spike protein | • Associated with several large outbreaks in California, but it remains unclear if the surges are driven by the variant itself • Effects on vaccine efficacy under investigation |
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