More long-term care workers are getting vaccinated against flu than ever before, but inoculation rates among those they care for have dropped significantly, according to federal health officials.

Overall flu shot coverage has continued to increase among all healthcare workers, officials from the Centers for Disease Control and Prevention and the National Foundation for Infectious Diseases shared Thursday during a press conference. Long-term care workers showed an especially notable increase in vaccination rates, reaching 69% during the 2015-2106 flu season, compared to 64% the previous season.

That increase is an encouraging trend for a group of workers that cares for some of the country’s frailest patients, said CDC Director Tom Frieden, M.D., M.P.H.

“This is progress, but it still leaves too many unprotected from flu,” Frieden added. “The more people who get vaccinated, the fewer preventable illnesses, hospitalizations and deaths from flu we will see in the coming months.”

Older adults had the most significant decreases in vaccination rates over the last flu season, the CDC reported. Rates for those over the age of 65 dropped 3.3 percentage points to 63.4%. Meanwhile, the vaccination rate dropped 3.4 percentage points to 43.6% of adults between ages 50 and 64.

Officials didn’t give reasons why the rates decreased, but noted that the drops are “concerning” since seniors are disproportionately affected by the flu.

“During the severe 2014-2015 season, more than three-quarters of the nearly one million people hospitalized due to influenza were age 65 years and older,” said William Schaffner, M.D., medical director for the NFID. “Vaccination not only reduces the chance that older adults will get the flu, it can help keep them out of the hospital by reducing the severity of the infection and related complications if they do get the flu.”