A study in Nature Microbiology suggests trace-level cytokines, a marker of cardiac inflammation, may play a key role in long-COVID cardiac symptoms, including chest pains and shortness of breath.

The findings were based on blood samples collected from 50 COVID-19 patients in Australia collected up to 18 months after infections. People reporting long-COVID symptoms had elevated levels of cytokines, which are proteins the body makes to fight inflammation.

Lab studies showed these trace-level cytokines had a direct effect on the functionality of cardiomyocytes, the cells of the heart responsible for its pump function.

“Lab studies showed these trace-level cytokines had a direct effect on the functionality of cardiomyocytes, the cells of the heart responsible for its pump function,” said study author Kirsty Short, PhD, of the University of Queensland in a press release from that university. 

Analysis showed participants' cardiovascular-specific long COVID symptoms had a more pronounced upregulation of inflammation-related pathways/terms, including neutrophil degranulation, antimicrobial peptides, and response to bacterium pathways, the authors said. 

"We’re now curious to know whether our findings could be applied to other symptoms of long COVID such as neurological disease or respiratory disease, as this study actively recruited sufferers with chest pain and/or heart palpitations," said Short, who added that  these initial findings need validation in larger studies. 

Novavax yesterday announced that the US Food and Drug Administration (FDA) has released a clinical hold on its new drug application for its COVID-flu combination and standalone flu vaccines. In a statement, the company said the step paves the way for it to begin enrolling participants for a phase 3 trial.

The FDA announced the clinical hold on October 16, following a report of a serious adverse event in a participant who received the combination vaccine as part of a phase 2 trial that wrapped up in 2023. The event was initially reported as motor neuropathy, which was later defined as amyotrophic lateral sclerosis (ALS), a condition not known to be immune-mediated or associated with vaccination. The FDA concluded that the event was not related to the vaccine.

Robert Walker, MD, chief medical officer at Novavax, thanked the FDA for its thorough review of additional information it submitted to the agency. "The information provided to the FDA supported our assessment that the serious adverse event was not related to our vaccine. We plan to start our Phase 3 trial as soon as possible."

The candidate vaccines are part of Novavax's portfolio of recombinant protein-based vaccines that use nanoparticle technology and the company's Matrix M adjuvant to boost the immune response.

An intervention to reduce antibiotic treatment of asymptomatic bacteriuria (ASB) at critical-access hospitals (CAHs) was associated with small but clinically significant improvement, researchers reported yesterday in Infection Control & Hospital Epidemiology.

Misdiagnosis and treatment of ASB—the presence of bacteria in the urine without other signs of infection—is a common practice and major driver of inappropriate antibiotic use in hospitals, particularly CAHs, which are primarily rural and have limited infrastructure for quality-improvement and antibiotic stewardship programs. 

To address the problem, researchers at the University of Washington Center for Stewardship in Medicine created a stewardship collaborative centered on an inappropriate diagnosis of urinary tract infection (ID-UTI) measure that has been shown to reduce ASB treatment in other types of hospitals. 

Reduction in ASB treatment not statistically significant

From October 2022 through July 2023, 1o CAHs participated in the quality-intervention program, which included learning labs, mentoring, and performance reports using the ID-UTI measure, which allowed hospitals to compare rates of ASB treatment. During the study period, ASB treatment at the CAHs fell from 28.4% during the first month to 18.6% during the final month, for an absolute reduction of 9.8%.

After adjusting for hospital clustering, the odds that a case treated for UTI was ASB non-significantly decreased by 6.5% with each additional month (adjusted odds ratio [aOR], 0.935; 95% confidence interval [CI], 0.873 to 1.001). There was no change in antibiotic duration or unjustified fluoroquinolone use.

"Although the reduction in ASB treatment was not statistically significant, the estimated effect size was fairly substantial and thus potentially clinically significant," the study authors wrote, adding that the findings indicate the ID-UTI measure can be implemented in resource-limited settings. 

"Future work over a longer period should be done to ensure that the decrease in overtreatment in ASB can be sustained," they concluded.