How many cases of COVID-19 have gone unreported, having been mild enough to be excused as just a seasonal cold, or due to the lack of availability of diagnostic testing, gone undiscovered entirely? The dearth of test kits globally has skewed our understanding of actual disease prevalence and local infection rates within our communities.
While some nations were better prepared to ramp up production of the tests used to identify active infections of COVID-19 such as instituting innovative drive-through testing stations and broadening the criteria for who is eligible to be tested, the United States has been unable to institute a coordinated and targeted public health screening approach. In the past several weeks, state departments of health and county public health agencies have struggled to procure test kits, get state laboratories certified as testing sites and thus respond to the ever-growing need for testing at the community level.
Given this reality, it seems unlikely we will be able to make up for lost time to roll out a broad screening test program and get ahead of the infection curve.
Alas, a true understanding of the impact of the COVID0-19 won’t come from the RNA-based diagnostic tests now being given, which look for the presence of viral genes in a nose or throat swab, a sign of an active infection. Rather, scientists need to test a person’s blood for antibodies to the new virus, known as Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2)1. Such tests can be used to understand the path the disease has taken by identifying antibodies developed against pathogens of those exposed to the virus. Such antibody tests can also detect active infections.
There is hope now that efforts by scientists and companies around the globe2 to develop antibody tests will provide data by indicating how much of the population is already immune because of asymptomatic or mildly symptomatic infections. Efforts to model the course of the pandemic should become more refined and accurate as antibody data could offer a key to how fast the virus will continue to spread.
Such data could inform practical issues such as whether and how to reopen schools, restaurants and businesses that have been closed. Understanding how long immunity to the virus lasts will be a key data point for those developing future vaccines. The urgency to develop and disseminate an antibody test is clear, and essential if we are ever to understand the true epidemiologic spread associated with COVID-19.