A new meta-analysis of 16 studies reveals that, for pre-exposure prophylactic vaccination (PrEP, which is used for disease prevention), the vaccine effectiveness (VE) of one Jynneos dose ranged from 35% to 86%, and VE for  post-exposure prophylactic vaccination ranged from 78% and 89% for one dose.

The findings are published on the preprint server medRxiv and represent the most current evidence of vaccine protection offered by Jynneos, Bavarian Nordic's two-dose vaccine used for the past 2 years to fight a global mpox outbreak. The study has not yet been peer-reviewed.

As of February 2024, more than 94,000 confirmed mpox cases have been documented in 117 countries in an outbreak that mostly affected men who have sex with men. Jynneos, also called MVA-BN, can be administered prophylactically either before or after exposure to confirmed mpox cases in two doses, administered 28 days apart.

The analysis included data from six countries: the United States, Canada, Spain, the United Kingdom, Israel, and the Netherlands.

Different administration routes protective

In eight studies, the VE of one dose of MVA-BN administered as PrEP was 35% to 86%, while five studies reported two-dose adjusted VE estimates ranging from 66% to 90%.

Two studies also provided VE estimates for administering Jynneos with intradermal injection or subcutaneously, and found similar ranges of protection regardless of administration route: 80% (95% confidence interval [CI], 23% to 95%) for intradermal administration, 89% (95% CI, 56% to 97%) for subcutaneous administration, and 87% (95% CI, 69% to 95%) when administered via a combination.

The authors conclude that the findings "demonstrated the effectiveness of one or two doses of MVA-BN against symptomatic mpox infection in outbreak settings."

A laboratory- and population-based surveillance study conducted in nine states found a low incidence of carbapenem-resistant Acinetobacter baumannii (CRAB) infections, but most isolates carried a carbapenemase gene and had limited treatment options, researchers reported this week in the American Journal of Infection Control.

Using data collected through the Emerging Infections Program's Multi-site Gram-negative Surveillance Initiative (MuGSI) from January 1 through December 31, 2019, researchers from the Centers for Disease Control and Prevention analyzed 136 CRAB cases in 125 patients. The crude incidence rate was 0.70 cases per 100,000 population.

Of the 66 CRAB isolates submitted for further analysis, 37 (56.1%) were from men, 36 (54.6%) were from Black or African American patients, 50% were collected from outpatient settings, and the median age of patients was 63.5 years. Whole-genome sequencing found that 48 isolates (72.7%) harbored an acquired carbapenemase gene, mainly bla_OXA-23 or bla_OXA-24/40. One isolate harbored bla_NDM. The isolates were resistant to many first-line antibiotics used to treat CRAB infections, with 50 (75.8%) defined as difficult to treat (DTR). Of the 11 case-patients who died, 9 had isolates that met the DTR definition.

Cefiderocol, which was approved by the Food and Drug Administration in 2019, had the most in vitro activity against the CRAB isolates among the 19 antibiotics tested.

Defining the landscape of CRAB

The study authors say the detailed clinical and microbiologic data allow for a deeper understanding of the epidemiology of CRAB across the spectrum of healthcare.

"This surveillance activity has demonstrated its value in helping to define the landscape of CRAB by providing a unique view of the molecular epidemiology of CRAB in the U.S., reinforcing the importance of tracking emerging and potentially transmissible resistance in A. baumannii complex to help inform and evaluate infection prevention and control strategies," they wrote.

At least 12 people in California and Washington state have been sickened and 7 people hospitalized in an Escherichia coli O157 outbreak traced to Gibson Farms organic walnuts that are sold in 19 states, the Centers for Disease Control and Prevention (CDC) said in a food safety alert yesterday.

Two patients developed hemolytic uremic syndrome, a serious and potentially fatal kidney condition. The CDC said in a news release, "Almost all sick people purchased organic walnuts from bulk bins in food co-ops or natural food stores in California and Washington." Two people bought bulk walnuts from the same store.

Company recalls bulk walnuts

In a recall notice yesterday, the Food and Drug Administration (FDA) said Gibson Farms has voluntarily recalled the implicated walnuts. "Gibson Farms Organic Light Halves and Pieces shelled walnuts were sold in bulk boxes in Net Wt. 25 lbs quantities and can be identified by lot 3325-043 & 3341-501 with expiration dates 5/21/25 & 6/7/25."

The agency added, "A full investigation is currently under way to determine the potential source of the contamination."

The CDC said the nuts were distributed to natural food and co-op stores in Alaska, Arkansas, Arizona, California, Colorado, Hawaii, Idaho, Kansas, Louisiana, Montana, Nebraska, New Mexico, Nevada, Oregon, South Dakota, Texas, Utah, Washington, and West Virginia. The FDA has posted a list of stores that sold the walnuts.

Gibson Farms, Inc, is headquartered in Hollister, California.

First patient fell ill on February 1

The 12 patients—6 in California and 6 in Washington—range in age from 6 to 84 years, with a median age of 57. Eight are female. Of 10 patients who reported racial information, 9 are White and 1 is Black.

Illness-onset dates range from February 1 to April 4. No deaths have been reported.

"The true number of sick people in this outbreak is likely much higher than the number reported, and the outbreak may not be limited to the states with known illnesses," the CDC said.