Antibody tests at home don’t show coronavirus infection reliably

The antibody test of coronavirus at home does not reliably indicate whether the person currently has a coronavirus infection, said the National Institute for Health and Welfare (THL) in a press release on Tuesday.

Home tests for coronavirus are currently also for sale in Finland. The available home tests are antibody tests that will give a preliminary assessment of whether you have previously had the coronavirus disease.

The THL also recommended that if anyone notices symptoms suitable for a coronavirus infection, the person must always get tested for free by professionals.

Antibody tests at home are performed on a blood sample from a person’s fingertip. The tests detect antibodies formed by the body against coronavirus, not directly the virus itself. The antibodies rise to a detectable level in the blood within approximately one to three weeks of infection. In the early stages of a coronavirus infection, the test may give a negative result due to insufficient antibodies having formed. The antibody test also cannot confirm whether the virus has left the person’s body at the end stages of the disease.

In addition to antibody tests, there are antigen tests for coronavirus home testing. Antigen tests are suitable for the detection of an acute coronavirus infection and identifying an infection best, when no more than five days have passed from the onset of symptoms. Antigen tests intended for home testing carrying a CE marking are not yet available on the Finnish market.

“If you observe even one symptom suitable for the coronavirus disease, always get tested by a professional and, otherwise, stay at home,” said THL Senior Specialist Carita Savolainen-Kopra.