The Alpha variant of SARS-CoV-2 evolved mutations that allowed it to more efficiently suppress the immune system’s early response to infection.
The variant known as alpha or B.1.1.7 or 201/501Y.V1 was first documented in the United Kingdom in September 2020, it spread rapidly around the world, suggesting it was significantly more transmissible than the original virus. It became the dominant variant in the U.S., where the CDC classified it as a variant of concern.
The variant has shown 30-50% enhanced transmissibility compared to initially merged SARS-CoV-2. It contains several key mutations in the spike protein – the key the virus uses to gain entry to human cells – that mark it out from the original Wuhan strain. One is a N501Y mutation, which improves spike protein binding to cellular receptors making the virus more contagious.
In the U.S., in mid-April 2020—before Delta became predominant—Alpha comprised 66% of cases.
Studies have suggested the B.1.1.7 lineage is more likely to land infected people in the hospital and is deadlier than the original virus.
Alpha-variant covid-19 (B.1.1.7)
