Post by Nadica (She/Her) on Jun 15, 2024 9:35:41 GMT
Low-cost, at-home antibody test can flag low immunity against COVID-19, researchers say - Published June 13, 2024
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.
"Our research suggests that an antibody test taken at home will allow at-risk individuals to conveniently identify inadequate immunity to COVID-19 in a world in which population immunity is declining," coauthor John Lafleur, MD, PhD, of George Washington University (GWU), said in a GWU news release. "This can be important information for those who are considering booster vaccination, but question whether or not it is needed."
Booster uptake in the United States has been low despite its ability to reduce the risk of severe disease. "Even among 65 and older US residents, the bivalent booster uptake has been reported as under 41%, suggesting the need for new strategies to build confidence and promote the use of the SARS-CoV-2 vaccine," the authors wrote.
They noted difficulties interpreting negative results: "Redesigning the tests to specifically detect negative Ab [antibody] results with clear instructions for interpreting those results will prevent any positive results that could mislead people into believing they are completely protected against COVID-19."