Virus World

In what is believed to be the first published study of COVID-19 vaccine effectiveness in long-term care facilities such as nursing homes, a research team co-led by the Yale School of Public Health found a widely used vaccine is highly successful in preventing infections. Residents of such facilities, particularly those in skilled nursing facilities (SNFs), have experienced disproportionately high levels of COVID-19–related death and illness since the pandemic first arrived in the United States nearly a year ago.  Despite this, this group was not included in COVID-19 vaccine clinical trials and there is limited post-shot vaccine effectiveness data available for members of this population who are typically older, more frail, and have more underlying medical conditions than the general population. For the study, researchers were able to capitalize on the rapid vaccine rollout in Connecticut's nursing homes facilitated by the state Department of Public Health. Specifically, they examined the "real-world" effectiveness of the Pfizer-BioNTech vaccine among 463 residents in two nursing homes in Connecticut that were experiencing COVID-19 outbreaks. They found that the vaccine had an estimated effectiveness of 63% against SARS-CoV-2 infection among facility residents after the first dose. This is similar to estimated effectiveness for a single dose of COVID-19 vaccine in adults across a range of age groups in non-congregate settings and strongly suggests that a complete two-dose vaccination offers significant protection for medically frail and older adult residents of SNFs.

"This confirms what we had all hoped: This vaccine is highly effective in perhaps the most at-risk group and can potentially save many lives," said Sunil Parikh, an associate professor at the Yale School of Public Health and the study's senior author. "Vaccines work in this highly vulnerable population and their implementation should not be delayed." The findings were published March 15 as an "early release" in the Centers for Disease Control and Prevention's (CDC) Morbidity and Mortality Weekly Report. The study was a joint collaboration with state and federal partners—the Connecticut Department of Public Health and the CDC—and involved two Ph.D. students at YSPH, Jillian Armstrong and Hanna Ehrlich. "This is a great demonstration of the power of collaboration between applied public health at the local and federal levels and academic public health entities," said Parikh. Since the early days of the pandemic, Connecticut has partnered with Parikh and others at the Yale School of Public Health to conduct enhanced surveillance in all Connecticut nursing homes. This surveillance system enabled the rapid detection of outbreaks.

Research published in  MMWR (March 15, 2021):

http://dx.doi.org/10.15585/mmwr.mm7011e2 

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can spread rapidly within skilled nursing facilities. After identification of a case of Covid-19 in a skilled nursing facility, we assessed transmission and evaluated the adequacy of symptom-based screening to identify infections in residents.

We conducted two serial point-prevalence surveys, 1 week apart, in which assenting residents of the facility underwent nasopharyngeal and oropharyngeal testing for SARS-CoV-2, including real-time reverse-transcriptase polymerase chain reaction (rRT-PCR), viral culture, and sequencing. Symptoms that had been present during the preceding 14 days were recorded. Asymptomatic residents who tested positive were reassessed 7 days later. Residents with SARS-CoV-2 infection were categorized as symptomatic with typical symptoms (fever, cough, or shortness of breath), symptomatic with only atypical symptoms, presymptomatic, or asymptomatic.

Twenty-three days after the first positive test result in a resident at this skilled nursing facility, 57 of 89 residents (64%) tested positive for SARS-CoV-2. Among 76 residents who participated in point-prevalence surveys, 48 (63%) tested positive. Of these 48 residents, 27 (56%) were asymptomatic at the time of testing; 24 subsequently developed symptoms (median time to onset, 4 days). Samples from these 24 presymptomatic residents had a median rRT-PCR cycle threshold value of 23.1, and viable virus was recovered from 17 residents. As of April 3, of the 57 residents with SARS-CoV-2 infection, 11 had been hospitalized (3 in the intensive care unit) and 15 had died (mortality, 26%). Of the 34 residents whose specimens were sequenced, 27 (79%) had sequences that fit into two clusters with a difference of one nucleotide. 

Rapid and widespread transmission of SARS-CoV-2 was demonstrated in this skilled nursing facility. More than half of residents with positive test results were asymptomatic at the time of testing and most likely contributed to transmission. Infection-control strategies focused solely on symptomatic residents were not sufficient to prevent transmission after SARS-CoV-2 introduction into this facility.

Published in N. Eng. J. Medicine (April 24, 2020):

https://doi.org/10.1056/NEJMoa2008457

A federal advisory committee to the Centers for Disease Control and Prevention voted Tuesday to recommend who should get COVID-19 vaccines first once one is authorized for use. The 14 voting members of the Advisory Committee on Immunization Practices, along with representatives from federal science agencies and the health care industry, voted during an emergency meeting online to recommend that the first COVID-19 vaccines should go to health care workers and residents of long-term care facilities, including nursing homes and assisted living. The CDC estimates that most people in these high-priority groups could be fully vaccinated by early next year if the Food and Drug Administration authorizes a vaccine by mid-December, as is currently anticipated. But because supplies will be short in the first few weeks after that authorization, individual health care and long-term care facilities will likely need to determine their own priority schedules for vaccination once they've obtained the vaccine. Long-term care facilities include nursing homes, assisted living and other residential facilities. The CDC estimates that 48 million doses will be needed to vaccinate these groups, which account for about 24 million people. It's anticipated that as many as 40 million doses could be available by the end of December, with 5 million to 10 million available each week afterward. The recommendations from the independent advisory committee now go to CDC Director Robert Redfield for final approval.

The issue of which risk groups should be prioritized for a COVID-19 vaccine has been a key topic at the group's regular public meetings over the past several months. The committee's goal is to use a COVID-19 vaccine to reduce severe illness and death from the disease and to lessen disruptions to society and the economy from the pandemic. In earlier meetings, the committee has considered four overlapping groups that might receive priority access to COVID-19 vaccines while immunizations are in short supply. The groups include health care workers and other essential workers who have a higher risk of exposure to the virus. Also included are people 65 and over and those with certain underlying medical conditions who are more likely to become severely ill if they contract COVID-19. Health care workers have long been considered to be first in line because they are exposed directly to COVID-19 through their work, and because protecting them and their patients from the virus would help reduce the spread of the coronavirus and keep the health system running. 

What's been more controversial is whether to add nursing home residents and other long-term care facility residents to the initial priority group. (Staffers at these facilities are considered health care workers.) At a public meeting last week, members of the committee agreed that the death toll in this population, a subgroup of the over-65 category, has been severe. Staff and residents at long-term care facilities represent just 6% of confirmed coronavirus cases but account for nearly 40% of COVID-19 deaths.  Still, some committee members raised concerns about giving newly authorized COVID-19 vaccines to nursing home residents. "This population is not a population that's been studied in the vaccine trials," said Dr. Robert Atmar, a professor of infectious diseases at Baylor College of Medicine, during last week's meeting. Older people who are participating in vaccine trials are generally in good health, while nursing home residents are often frail. "Coming back to the science of it, we really are not able to assess the balance of benefits and harms," he said. Another committee member worried that introducing COVID-19 vaccines first to nursing home residents could erode public confidence in the safety of the vaccines. Given the high mortality rate in long-term care facilities, it's likely that some nursing home patients who receive COVID-19 vaccines could die shortly after from other causes, said Dr. Helen Keipp Talbot, an associate professor of medicine at Vanderbilt University Medical Center.  "I think you're going to have a very striking backlash of, 'My grandmother got the vaccine and she passed away.' They're not likely to be related, but that will become remembered," she said.

Before a COVID-19 vaccine is recommended for use among nursing home residents, Talbot suggested running a limited clinical trial in this population to gather data that would show the vaccine is safe for this group. Tuesday's vote comes in advance of a COVID-19 vaccine receiving FDA authorization. The CDC committee previously said it would wait for authorization before making vaccine recommendations. But in recent weeks, it has undergone pressure from the federal government to move faster. "We are not dependent on any delay from [the advisory committee] in terms of helping to advise states," Alex Azar, secretary of health and human services, said at a Nov. 24 press briefing, discussing his intent to move quickly with the vaccine distribution process. States will use the CDC guidance as they place orders for COVID-19 vaccine doses. Their first orders are due to the federal government Friday.