The Defense Department admitted Thursday the force is still far from safety as many troops continue declining to get the COVID-19 vaccine.

For months, the military has struggled to convince service members to accept the voluntary coronavirus vaccine as the department increased its supply to match global distribution. The military is finally catching up, with nearly 1.5 million defense personnel vaccinated. Some 58% of the force has received at least one dose, and 44% has been fully vaccinated. Still, a Pentagon official said the military is far from reaching herd immunity.