COVID-19 Variants of Concern (VOCs)

PHO is working with the Ontario Ministry of Health, the provincial testing network for COVID-19 and other lab, research and health care partners to test for and monitor COVID-19 variants of concern (VOCs) in Ontario.

Variants are viruses that have changed or mutated. Variants are common with coronaviruses; however, a variant becomes a VOC when its changes have a clinical or public health significance that affects one or more of:

  • transmissibility (spread)
  • virulence (severity of disease)
  • vaccine effectiveness
  • diagnostic testing

VOCs identified globally and in Ontario include:

  • B.1.1.7 variant first identified the UK
  • B.1.351 variant first identified in South Africa
  • P1 variant first identified in Brazil
  • B.1.617 variant first identified in India

PHO is actively monitoring, reviewing and assessing international research on COVID-19 variants. Please see the Synopsis of Key Articles webpage for summaries of COVID-19 variant research.


Updated 19 May 2021