My antibody test results say I do not have clearly detectable antibody levels, but I previously I know that I have had COVID-19. What does this mean?

This could be because:

– Antibody status (both the level of the antibodies and the type of antibodies) changes over time from the point of infection, and so antibody levels may have declined over time.

– You may have been exposed to COVID-19 but have different antibodies that this research test is not designed to pick up.

You should continue to follow all guidance on self-isolation and social distancing as appropriate. In addition, we encourage all study members to have the COVID-19 vaccine when offered, regardless of antibody results.