The CAL.20C variant from Southern California is spreading rapidly

Los Angeles – The CAL.20C variant, thought to be responsible for the increase in disease in Southern California, has spread to at least 6 other countries. According to a report in American Medical Journal (Gamma2021; DOI: 10.1001 / jama.2021.1612) More than 5 mutations, 3 of them are in protein spike.

Employees of the National Institute of Allergy and Infectious Diseases (Nyade(In the editorial)Gamma, 2021; DOI: 10.1001 / jama.2021.2088) Especially the L452R mutation, which is present at the receptor binding site and can induce immune escape.

The CAL.20C variant was first detected in July 2020 in a single sample in the Los Angeles area. Temporarily undetected, it resurfaced in Southern California in October. Then it quickly spread in November and December.

It is currently responsible for nearly half of the confirmed infections in the area, according to Jasmine Plummer of the Cedars-Sinai Center in Los Angeles. The virus has also spread to 19 states in addition to Washington, DC.

Outside the United States, CAL.20C has already been detected in Australia, Denmark, Great Britain, Israel, New Zealand and Singapore. Plummer suspects the substitute was distributed through Los Angeles International Airport, the nation’s second-largest airport by number of passengers. Despite the pandemic, 2 million travelers were handled there in November and December. Top destinations included Australia and New Zealand, which explains the emergence of new variants in Plummer countries.

The CAL.20C variant differs from the strain 20c, which is currently the most prevalent in the United States, by 5 mutations, 2 of which (I4205V and D1183Y) are found on the genes of the polyclonal proteins that the virus needs to multiply in cells. The other three mutations (S13I, W152C, and L452R) are located on the spiky protein gene.

L452R is located at the receptor binding site and could influence binding of some therapeutic monoclonal antibodies, a team led by Anthony Fauci, president of the US National Institute of Allergy and Infectious Diseases, wrote in the editorial.

In fact, L452R is one of the mutations that was identified in a previous clinical laboratory study in cell (2020; DOI: 10.1016 / j.cell.2020.07.012) Decreased antibody neutralization in recovered individuals. According to Plummer, it has yet to be investigated whether this also applies to the CAL.20C variant. There is also no information about whether the vaccines protect against the virus and whether the mutations have altered the pathogen of the virus. © rme / aerzteblatt.de