Editor's note: The headline of this article was corrected on Jan 31 to state the correct risk reduction for vaccinated residents: 23% to 33%, not 30% to 50%.

A study today in Morbidity and Mortality Weekly Report finds that US nursing home residents who weren't up to date on recommended COVID-19 vaccines were at a 30% to 50% higher risk for infection than those who were current—or a 23% to 33% lower risk for vaccinated residents.

From Oct 10, 2022, to Jan 8, 2023, Centers for Disease Control and Prevention (CDC) researchers analyzed data from the CDC's National Healthcare Safety Network (NHSN) on weekly COVID-19 infections among nursing home residents.

The team compared infection rates among residents who had received the recommended primary monovalent (single-strain) vaccine series and either a monovalent booster dose within the past 2 months or the newer bivalent (two-strain) booster.

Federal mandates require nursing homes certified by the Centers for Medicare & Medicaid Services to report weekly infection and vaccination data to NHSN, the researchers said. Each of the 15,049 facilities reported such data for at least 1 week during the study period, and the vast majority submitted data for all 13 weeks.

Under 50% received a booster

Up-to-date vaccination status was low throughout the study period, rising from 37.5% the week of Oct 23 to 48.9% by study end. Weekly COVID-19 infection rates among unboosted residents were higher than those among booster recipients (range, 9.5 to 18.8 per 1,000 residents vs 7.2 to 15.6), with incidence rate ratios (IRRs) indicating that unboosted residents were at higher risk than their boosted peers (range, 1.3 to 1.5).

This study supports other recent findings that the bivalent booster dose offers additional protection.

"The proportion of nursing home residents in this study who were up to date (48.9%) was lower than the percentage of nursing home residents who completed a primary series (86.1%) and who received monovalent booster doses (87.0%)," the researchers wrote.

The authors noted that nursing home residents are at high risk for COVID-19 infection and poor outcomes, including death because they typically are older, have more chronic conditions, and live in a congregate-care setting.

"This study supports other recent findings that the bivalent booster dose offers additional protection in persons who previously received monovalent vaccines," they wrote.

More highly pathogenic avian flu outbreaks have been reported in poultry in five states, including commercial turkey farms in Iowa and Virginia, the US Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) said in updates over the past few days.

Iowa's outbreak occurred at a turkey facility in Buena Vista County that houses 27,700 birds, marking the state's first outbreak of 2023, following seven outbreaks at the state's turkey farms in December. In Virginia, the virus struck a turkey farm that has 10,600 birds, the second affected farm in Rockingham County in less than a week.

Meanwhile, more outbreaks in backyard flocks were reported in New York, Oregon, and New Hampshire.

Since the Eurasian H5N1 strain was first detected in US poultry in February 2022, outbreaks have led to the loss of 58.2 million birds across 47 states.

So far 7 human cases

Globally, the virus continues to strike poultry and wild birds on multiple continents, and the H5N1 clade circulating in poultry has sickened several mammal species and was recently found to transmit among minks at a commercial mink farm in Spain, heightening concerns about further adaptation to mammal airways, including humans.

Seven human infections have been reported, all in people who had close contact with sick poultry. Some were mild, but some were severe or fatal.

The Quadripartite organizations announced yesterday the establishment of a technical group that will help guide countries in their efforts to monitor antimicrobial use and resistance.

The technical group will advise the Quadripartite Organizations—the World Health Organization (WHO), the World Organization for Animal Health, the Food and Agriculture Organizations of the United Nations (UN), and the UN Environment Programme—on the needs, scope, and form of integrated surveillance necessary for countries to be able to accurately track antimicrobial use (AMU) and antimicrobial resistance (AMR) in humans, animals, and the environment.

Integrated surveillance is considered one of the critical elements of the multisectoral national action plans on AMR that countries have been tasked with developing by the WHO and the UN. But many countries, particularly low- and middle-income nations, have limited capacity for building strong surveillance systems.

The group will include experts in AMU and AMR surveillance across sectors, including human health, terrestrial and aquatic animal health, plant health, food systems, and the environment. One of their goals will be to create a harmonized, sector-specific framework for how antimicrobials are used and monitored and how AMR surveillance is conducted.

"Effective surveillance of antimicrobial use and resistance within and across sectors is an integral part of efforts to monitor the spread and impact of resistance and to mount an effective One Health response," Hanan Balkhy, WHO Assistant Director-General on AMR, said in a press release.