PHO’s COVID-19 Serosurveillance Initiative

Serosurveillance is an application of serology testing, which is a test performed on blood to detect the presence of antibodies. Serosurveillance is a common public health surveillance method.

Early in the pandemic, PHO conducted serosurveillance using anonymized blood specimens to better understand what proportion of the Ontario population had COVID-19 antibodies and to identify hotspots and high risk groups.

Results of PHO's serosurveillance program helped to support the public health system and the government to evaluate the effectiveness of the early pandemic response and to take targeted steps to prevent the spread of COVID-19.

PHO is shifting its focus from serosurveillance for the time being to focus on validating new laboratory methods for measuring antibody response to COVID-19, as well as leading and contributing to research studies investigating vaccine protection against COVID-19.


Updated 30 June 2021