BIRMINGHAM, Ala. (AP) — Coronavirus cases have dropped at U.S. nursing homes and other long-term care facilities over the past few weeks. The dip offers a glimmer of hope that health officials attribute to the start of vaccinations, an easing of the post-holiday surge and better prevention, among other reasons. Statistics show that more than 153,000 residents of the country’s nursing homes and assisted living centers have died of COVID-19, accounting for 36% of the U.S. pandemic death toll. Although experts say the vaccination rollout may be contributing to the drop in cases, other factors are likely playing a larger role. And they caution that threats are still looming, including new strains of the virus.