SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) also known as 2019-nCoV (2019 Novel Coronavirus) is a virus that causes illnesses ranging from the common cold to severe diseases. Lineage B.1.429, also known as CAL.20C, with S13I, W152C, L452R mutations in the spike proteins, of which the L452R was of particular concern. B.1.429 is possibly more transmissible, but further study is necessary to confirm this. CDC has listed B.1.429 and the related B.1.427 as "variants of concern," and cites a preprint for saying that they exhibit a ~20% increase in viral transmissibility.