What will antibody testing do for the management of COVID-19?

We are told again and again that the reported COVID-19 data, both the number of cases and the number of deaths, vastly underestimate the true counts. We know that many asymptomatic cases are missed completely, while mild cases are either missed or undercounted. Access to testing is spotty and not 100% accurate, with some reports of the false negative or “miss” rate as high as 30%. All of this leads to the conclusion that there is a massive iceberg of COVID-19 cases lying below the surface of what we have detected.

Knowing the composition of cases under the surface and how these cases vary by age, race, gender and other demographic factors will help inform both the current allocation of resources and future preparedness efforts. Antibody tests can be helpful here as they can detect whether a person has been infected in the past, leaving them with antibodies in their blood that might protect against future infection. These serology tests could prove to be particularly important as we begin to emerge from the current wave of infection and test the safety boundaries of policies surrounding return to school, work and life as we once knew it.

Antibody testing will neither slow nor stop COVID-19. This particular virus is likely to remain with us, just as other coronaviruses persist in our ecosystem. People will continue to get infected with COVID-19, but the opportunity for transmission will be diminished, we hope substantially so, as the number of susceptible individuals will be fewer. Knowing who is susceptible and who is not will help us manage the next wave of infections. We do not know exactly when the next wave will come, but it will.

In the healthcare setting, knowing who has immunity to the disease, even if it is short-term, will inform policies about who is best suited to care for infected patients. In the community, those with established immunity will be able to more rapidly resume normal activity and be of help to those who must remain isolated.

Although companies and labs globally have been working to produce antibody tests, they are not yet widely available, and their accuracy is still being evaluated. Short of a vaccine, knowing the level of herd immunity in a population is the best measure of what the future holds. Pre-deployment of resources will be essential in the coming year as we see the virus re-emerge and we work to keep it under control. We must encourage the allocation of resources to allow for widespread and free antibody testing.

Jennifer Pinto-Martin, PhD, MPH, is a professor at the University of Pennsylvania School of Nursing and Perelman School of Medicine, and executive director of the Center for Public Health Initiatives