Last winter, West Virginia worked to ensure those in nursing homes received the COVID-19 vaccines. However, with COVID-19 cases and hospitalizations increasing once again, state officials now are questioning whether vaccinated residents’ immunity levels are decreasing.

Therefore, beginning in August, the state plans to start measuring antibody levels in vaccinated nursing home residents, helping to determine whether they need booster shots, according to Kaiser Health News. The process will be voluntary and the data will only be shared with federal health agencies in order to assess whether or not a booster shot is necessary.

Clay Marsh, M.D., executive dean for health sciences at West Virginia University and the coronavirus response coordinator of the state, estimated that about 10% of hospitalized COVID patients in West Virginia and 12% of deaths  were among fully vaccinated people. In West Virginia, COVID cases have more than tripled in the past month — largely due to the Delta variant.

Currently, the focus is on making sure people are getting vaccinated in the first place, as opposed to getting a booster shot. It is also unclear how quickly COVID vaccine protection fades. 

“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,” Mark Roboerts, M.D., professor and former chair of the health policy and management department at the University of Pittsburgh Graduate School of Public Health, told the news outlet.