Infections occurred weeks before first reported COVID-19 cases in US, NIH study shows
Researchers detected SARS-CoV-2 antibodies in blood specimens collected weeks before the first reported cases in several U.S. states — more evidence that the novel coronavirus was spreading earlier than originally thought.
The positive specimens were from seven people in Illinois, Massachusetts, Mississippi, Pennsylvania and Wisconsin and were collected as early as Jan. 7, suggesting that transmission was occurring “in states far from the initial hotspots,” researchers reported today in Clinical Infectious Diseases.
It was one of the first studies to use data from the NIH’s All of Us Research Program, “a national effort that aims to build one of the largest, most diverse databases of health information that researchers can use for broad discovery, including emerging diseases like COVID-19,” said Sheri D. Schully, PhD, the acting chief medical and scientific officer for the program.
“While our dataset was not set up to study COVID-19 specifically, we were able to leverage our scale and diversity, multiple data types, biosamples, and longitudinal design to better understand the early days of the U.S. epidemic,” Schully told Healio.
Schully and colleagues analyzed more than 24,000 stored blood samples contributed by program participants from all 50 states between Jan. 2 and March 18, 2020. According to the study, the researchers detected antibodies against SARS-CoV-2 using two different serology tests — the Abbott Architect SARS-CoV-2 IgG ELISA and the EUROIMMUN SARS-CoV-2 enzyme-linked immunosorbent assay (ELISA) — in nine participants’ samples outside the “urban hotspots” of Seattle and New York City, which researchers believed to be key points of entry for the virus in the U.S.
Seven of the nine had specimens collected on Jan. 7 in Illinois, Jan. 8 in Massachusetts, Feb. 3 in Wisconsin, Feb. 15 in Pennsylvania, and March 6 in Mississippi — prior to the first confirmed cases in those states.
“It is important that even if you think you had COVID-19 in these early days of 2020 — and our research shows it was present in the United States earlier than we initially thought — you should still get vaccinated,” Schully said. “Additionally, we think this illustrates the value longitudinal studies like All of Us add in answering emerging public health questions and the necessity of building the data infrastructure that partners participants and researchers with the goal of improving the health of future generations.”
Schully explained that these kinds of studies are important because they can help detect infections broadly, including in people who may have had no or mild symptoms and never got tested.
“There is still so much we don’t know about the emergence of SARS-CoV-2 in the United States, but this adds another piece to the puzzle and can help inform public health surveillance testing strategies, models on the entrance of the novel virus into susceptible populations, and subsequent intervention and mitigation efforts for future epidemics,” Schully said.