An at-home antibody test can gauge users' immunity to COVID-19, alerting to the need for a vaccine booster dose, a University of North Carolina–led research team reports in Science Advances.
The investigators evaluated the performance of the low-cost lateral-flow antibody test in 168 healthcare workers with weak COVID-19 vaccine responses. They also measured SARS-CoV-2 neutralizing antibody and T-cell responses among all participants before and after a third vaccine dose.
By the end of 2022, more than 96% of Americans 16 years old or older had SARS-CoV-2 antibodies from infection or vaccination, the study authors wrote. "However, immunity against SARS-CoV-2 tends to wane over time and is typically less effective against evolving SARS-CoV-2 variants."
Positive results don't necessarily show adequate immunity
A negative result on the test indicated low immunity, while a positive result didn't necessarily indicate sufficient immunity. Those who tested positive had higher antibody concentrations than those who tested negative. After wild-type SARS-CoV-2 booster vaccination, all participants gained systemic antibodies against evolving SARS-CoV-2 and related viruses.