The NWT government said on Tuesday it was not immediately pursuing Covid-19 antibody testing in the territory, cautioning the relationship between antibodies and immunity is still unknown.
Antibodies are proteins produced by the body in response to the presence of foreign invaders. Finding specific antibodies in the blood can indicate whether a virus has infected a person in the past.
In the case of Covid-19, accurate antibody testing can allow researchers to identify whether people have previously contracted the novel coronavirus responsible for the disease, allowing them to map the pandemic’s spread.
The precise date by which Covid-19 had reached North America remains the subject of speculation.
Quebec, Ontario, Alberta, and BC are among Canadian jurisdictions to have begun some form of the testing.
Some NWT residents had hoped antibody testing would offer them insight into whether bouts of illness they experienced in late 2019 were connected to the virus.
However, antibody tests can’t be used to tell whether someone currently has the disease. The NWT government said its efforts were focused on identifying active cases and preventing the disease’s future spread.
Mike Westwick, a spokesperson for the territorial government’s Covid-19 response team, said antibody tests can’t yet definitively prove someone is immune to the disease.
“It is unclear whether people with antibodies are immune to re-infection or if they are still infectious to others,” Westwick said by email.
The territory believes there is also not enough data to know how accurate antibody tests are when performed on seniors or immuno-compromised people, as age and condition can impact the body’s immune response.
Researchers do not yet know with certainty how long Covid-19 antibodies remain present in a person’s body after they recover from the infection.
“In low-prevalence settings such as NWT, positive antibody results will be rare. When they occur, many positive antibody results may in fact be false positives,” Westwick wrote.
“Our priority as a territory is to up our capacity for reliable, rapid diagnostic testing to bolster our response to Covid-19 moving forward.”