COVID-19 may be the worst health crisis the world has ever seen — and the virus keeps getting worse.The variants of concern (VoCs) are modified versions of the original strain of the SARS-CoV-2 virus, which causes the disease.The novel coronavirus, like other viruses, replicates when it enters a host’s cells.
But not all of the copies are the same. Errors in the replication process, called mutations, give rise to slightly altered viruses.