Nearly 87% of naturally infected COVID-19 patients maintained antibodies to SARS-CoV-2 proteins for at least 10 months, according to a new Labcorp analysis of specimens from 39,086 individuals.
The study, published May 24 in The Lancet-affiliated EClinicalMedicine, offers real-world evidence of the body’s response to the virus and the possibility of protection against future infection. It is the largest known COVID-19-related study by specimen volume of its kind, harnessing Labcorp’s robust testing infrastructure to enhance the public’s understanding of this potentially deadly virus.
“Our observational analysis provides an encouraging timeline for antibody development and sustainability among the U.S. population,” said David Alfego, PhD, Labcorp senior data scientist and the paper’s lead author. “We sincerely hope it sparks more research, helps unearth answers to complex questions and informs critical, post-pandemic planning.”
Alfego and a team of Labcorp scientists analyzed results from tests used to detect antibodies that guard against “spike” and nucleocapsid proteins on the SARS-CoV-2 virus. Their analysis included specimens collected from 39,086 individuals with COVID-19 and tested between March 2020 and January 2021.
By employing various techniques, Labcorp scientists were able to map rates of antibody positivity, as well as the correlation of a person’s age and sex on antibody status.
Notable findings include:
- While sample sizes varied each day after a positive COVID-19 test, the antibody positivity rate to the SARS-CoV-2 spike protein remained mostly stable for the U.S. population through 300 days after the initial test.
- The positivity rate of antibodies to the nucleocapsid protein—a coronavirus component that is more active during early infection—declined more rapidly than the rate of spike antibodies but remained above 60% through 10 months of testing.
- Individuals under the age of 65 showed a more sustained rate of positive antibody results, meaning those 65 and older may have increased difficulty maintaining antibodies for a prolonged period of time.
- There was no statistically significant difference in spike antibody positivity rates between males and females over time.
“This is good news for naturally infected individuals, and potentially for those who have been vaccinated,” said Brian Caveney, M.D., chief medical officer and president of Labcorp Diagnostics. “More research must be done to understand what type and level of antibodies suggest protection from reinfection. But the prolonged presence of certain antibodies is a promising sign as we continue thinking about safely emerging from the pandemic, as well as future vaccinations and the timing of booster shots.”