Like all viruses, COVID-19 mutates as it spreads through the population. During the pandemic, multiple versions (also called variants) of this virus have emerged and some have become more contagious than others. Variants are distinct from the original virus because of changes in the RNA code (genetic instructions for making proteins) that make up the virus. Most variants don’t have any clinical significance and do not cause illness in most people. However, some of the more common variants – called “variants of concern” (VOCs) or “variants of interest” – have been shown to be more contagious and more likely to cause severe disease. They also have mutations that allow them to escape from antibodies made by natural, vaccine-induced and monoclonal antibody responses.
These mutations are referred to as “escape mechanisms” and can render the available countermeasures less effective. CDC and WHO have identified some of these more dangerous mutants as a particular public health concern and have been monitoring their distribution globally.
Vaccination is the best way to protect against COVID-19 and slow the spread of this virus. To help ensure you’re protected, CDC recommends that everyone receive a single dose of the COVID-19 vaccine.