Seropositive Antibody Test – Future Infection

Angie Szumlinski Studies

“Since the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in late 2019, limited research has shown that the majority of patients who clear their infections develop serum antibodies against the virus that last for at least several months but may decline over time. Although it has been speculated that the development of antibodies may be associated with a decreased risk of reinfection, the evidence for this hypothesis is limited.

[In a recent study published in JAMA Internal Medicine,] a total of 3,257,478 unique patients with an index antibody test were identified after excluding 132 patients with discordant antibody tests on the index day. Of these, 2,876,773 (88.3%) had a negative index antibody result (seronegatives), 378,606 (11.6%) had a positive index antibody result (seropositives), and 2,099 (0.1%) had an inconclusive index antibody result. Early in the observational period, particularly in the first 30 days, positive NAAT results among seropositive patients are likely attributable to prolonged shedding of viral RNA… Beyond 90 days, the vast majority of viral shedding is expected to have ceased, so positive NAAT results seen at a later interval from the index antibody test may represent new infections.”

– “Association of SARS-CoV-2 Seropositive Antibody Test With Risk of Future Infection” Raymond A. Harvey, MPH; Jeremy A. Rassen, ScD; Carly A. Kabelac, B1; et al February 24, 2021

Bottom line, the research indicates that viral shedding may result in inaccurate testing, however the antibody positive tests were more pronounced after 30 days and progressively strengthened through the 90-day observation period. This is great news because it gives us more hope that not only are we seeing fewer cases of COVID-19, but that many of us are protected by our own immune systems!

Stay tuned, mask up if mandated, and stay well!