In the third such announcement in as many weeks, AstraZeneca revealed Monday that its vaccine candidate, developed by Oxford University, is up to 90 percent effective in clinical trials. Pfizer and its German partner, BioNTech, and Moderna have each reported vaccines that are 95 percent effective in trials.

All three have said they will seek regulatory clearance to offer their vaccines to millions of people. The drugmakers have moved at record speed, and the first shots of the Pfizer and Moderna vaccines could be given in the coming weeks. The path for the AstraZeneca vaccine is less clear.

An independent panel advising the Centers for Disease Control and Prevention voted Tuesday to recommend that residents and employees of nursing homes and similar facilities be the first people in the United States to receive coronavirus vaccines, along with health care workers who are especially at risk of being exposed to the virus. The panel, the Advisory Committee on Immunization Practices, voted 13 to 1 during an emergency meeting to make the recommendation. The director of the C.D.C., Dr. Robert R. Redfield, is expected to decide by Wednesday whether to accept it as the agency’s formal guidance to states as they prepare to start giving people the shots as soon as two weeks from now.

“We are acting none too soon,” said Dr. Beth Bell, a panel member and global health expert at the University of Washington, noting that Covid-19 would kill about 120 Americans during the meeting alone.

States are not required to follow the panel’s recommendations, but they usually do. The final decision will rest with governors, who are consulting with their top health officials as they complete distribution plans.

The new recommendation is the first of several expected from the panel over the coming weeks, as vaccines developed by Pfizer and Moderna go through the federal approval process, on the thorny question of which Americans should be at the front of the long line to get vaccinated while supply is still scarce. The panel described it as an interim recommendation that could change as more is learned about how well the vaccines work in different age groups and how well the manufacturers keep up with demand.

The roughly three million people living in long-term care and those who care for them are a relatively clear target; 39 percent of deaths from the coronavirus have occurred in such facilities, according to an analysis by The New York Times.

But states and health systems will ultimately have to decide which of the nation’s 21 million health care workers should qualify to receive the first doses, as there won’t be enough at first for everyone.

Pfizer and Moderna have estimated that they will have enough to vaccinate, at most, 22.5 million Americans by year’s end, with the required two doses, a few weeks apart. The C.D.C. will apportion the supply among the states, with the initial allocation proportional to the size of each state’s adult population.

The only member of the committee to vote against the recommendation was Dr. Helen Talbot, an infectious-disease specialist at Vanderbilt University, who expressed discomfort with putting long-term-care residents in the first priority group because the vaccines’ safety had not been studied in that particular population. “We enter this realm of ‘we hope it works and we hope it’s safe,’ and that concerns me on many levels,” she said before the vote.

But most panel members who offered opinions said they thought the high death rate among that group made it imperative to include it.

U.S. Senate investigators have discovered a pattern of neglect and poor care in an Oregon company’s group homes for people with intellectual and developmental disabilities, finding problems that persisted despite repeated state efforts to force the company to improve.

The 19-month investigation into Mentor Oregon, spearheaded by the U.S. Senate Finance Committee, was launched in response to coverage in The Oregonian/OregonLive that outlined neglect in one of the company’s homes in Curry County. State officials at the time learned of neglect so severe that a resident smelled of “rotting flesh,” according to official records.

The federal report summarizing the committee’s investigation, published Thursday, blasted the company for failing to meet its obligations towards the vulnerable people it serves.

“Scores” of the company’s homes were found to be in violation of various regulations from 2013 to 2019, the committee found after reviewing 5,000 pages of documents. The most common problems included staff failing to follow doctors’ orders, staff not getting training and residents missing medications.

At least one resident of the White Haven Center has died from COVID-19, Pennsylvania’s Department of Human Services reported on a webpage that tracks the disease at state facilities.

The website says “less than five” deaths have occurred at White Haven; the state suppresses exact numbers of deaths below five.

No White Haven residents had COVID-19 until the end of October, but now 31 of 97 residents have tested positive. Twenty-eight residents currently have the disease as of 5 p.m. Monday. That’s up from 11 active cases on Wednesday.

The age and health conditions of residents put them at a greater risk from COVID-19. As of February, only four residents were younger than 45, and 40 residents were non-ambulatory.

Among White Haven’s 367 workers, 51 have tested positive for the disease. Thirty-six currently have COVID-19.

None of the state’s other centers for people with intellectual disabilities has reported a death, but all have cases. At the Ebensburg Center in Cambria County, 50 of 186 residents have tested positive. Polk Center in Venango County has had 10 cases among 183 residents and Selinsgrove Center in Snyder County also had 13 cases among 195 residents.

Deaths have occurred at three of seven state hospitals: Norristown has 10 deaths while South Mountain and Wernersville each report less than five. Locally, the state hospitals at Clarks Summit and Danville have reported no cases among residents and less than five among employees.