Antibodies do decrease over time, “but that doesn’t tell us if you’re exposed to COVID whether your body will move into gear and produce more. … The question of whether antibodies are a marker of adequate immunity is one we have not answered yet,” Wasserman said.
West Virginia officials say their nursing home antibody testing could help FDA and other regulators evaluate the need for boosters.
“We want to gather this information and, pending what we find, work with Centers for Disease Control and Prevention and the Food and Drug Administration on an appropriate response,” said Marsh. “This is a complicated issue as antibodies are not the only defense against COVID.”
An antibody test will be used to measure levels against what was expected after immunization and whether it is a high-enough level to neutralize the delta variant, he said.
The state will also look at breakthrough infections and how many vaccinated people have ended up hospitalized or dead.
The state’s nursing home industry supports the initiative, although officials say they’ve seen no increase in vaccinated COVID-19 residents getting sick. “Our goal is to advance knowledge and information that exists about the vaccines,” said Marty Wright, CEO of the West Virginia Health Care Association, which represents nursing homes. He said antibody testing will offer one indicator of how well vaccines are still working.
Dr. David Wohl, professor of medicine and director of the vaccine clinics at the University of North Carolina School of Medicine, pointed out that even if the West Virginia initiative shows antibody levels have dropped, states can’t provide booster shots until the federal government authorizes them. “You do not do a test unless there is something you can do with the information that you get from the test,” he said.
Wohl said he anticipates that booster shots are likely to be needed eventually and that higher-risk populations — such as those who are immunocompromised or those in nursing homes — would likely be first to get them.
Dr. Mark Roberts, professor and former chair of the health policy and management department at the University of Pittsburgh Graduate School of Public Health, said immunity protection is much more complicated than just the level of antibodies. “It looks like protection from the vaccine wanes, but we don’t know exactly how fast, and if protection wanes it may still protect people from getting sick and dying,” he said.
Wasserman said a bigger question is whether officials are seeing more breakthrough infections in nursing homes and whether unvaccinated staff members are to blame.