To embed, copy and paste the code into your website or blog: The novel coronavirus undergoes a mutation about once every 2 weeks, or half the rate seen in influenza. What to Know Mutations of the virus have given rise to thousands of variants, only a few of which currently appear as a major threat due to increased infectivity, lethality, or vaccine resistance. In the US, the current major variant is the so-called “UK” variant (officially “B.1.1.7”), which is about 35-50% more infectious or transmissible, and can give rise to a rather more lethal form of COVID-19. The doubling time of the “UK” variant in the US, where it is expected to become the dominant form of the virus by March 2021, is estimated to be 9.8 days.