Quad high-dose flu vaccine tied to fewer hospitalizations in seniors

News brief

Danish seniors who received the quadrivalent (four-strain) high-dose influenza vaccine (QIV-HD) had fewer hospitalizations for flu and other conditions compared to their peers who received the standard quadrivalent flu vaccine (QIV-SD), according to a post-hoc analysis published late last week in Clinical Microbiology and Infection.

flu shot senior man
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The trial took place during the Northern Hemisphere's 2021-22 flu season. Researchers enrolled 12,477 participants, 6,245 who received QIV-HD and 6,232 who got the QIV-SD. Overall mean age was 71.1, and 47.1% were women. Just over 20% had underlying cardiovascular disease.

The researchers looked at a number of outcomes when comparing the two groups, beginning 14 days after vaccination until May 2022. Hospitalizations for pneumonia or influenza, respiratory hospitalizations, cardiorespiratory hospitalizations, cardiovascular hospitalizations, all-cause hospitalizations, and all-cause death.

60% greater protection

The investigators found that receiving QIV-HD was associated with lower rates of hospitalization for flu and pneumonia—10 events in the QIV-HD group compared with 33 in the QIV-SD group. Incidence rate ratio (IRR) was 0.30 (95% confidence interval [CI], 0.14 to 0.64), meaning 60% greater protection.

Trends favoring QIV-HD were observed over time, even before the flu season was under way. The team found the first statistically significant reductions in flu and pneumonia hospitalizations by the third calendar week of 2022. There were 5 such events in the QIV-HD group versus 15 in the QIV-SD group. IRR was 0.33 (95% CI, 0.11 to 0.94).

The researchers concluded that the impact on less specific outcomes outside of influenza circulation periods supports earlier findings, including from similar trivalent (three-strain) flu vaccines, that suggest broader effects from flu vaccination.

"Our exploratory results correspond to a number needed to treat of 65 (95% CI 35-840) persons vaccinated with QIV-HD compared with QIV-SD to prevent one additional all-cause hospitalisation per season," the authors wrote. "Further research is needed to confirm these hypothesis-generating findings."

Bangladesh reports 2 fatal Nipah virus cases

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A media outlet in Bangladesh has reported that two men have died from Nipah virus infections, and local officials said both had consumed raw date juice—a known risk factor for contracting the disease—before they became ill. The cases are the country's first of the year.

Nipah virus particles
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Nipah virus cases in Bangladesh follow a seasonal pattern, from December through May. The period coincides with the harvesting of palm sap and festivities related to the process. The sap can be contaminated by the saliva, urine, or droppings from fruit bats, which are thought to harbor the virus. The virus can then spread from person to person.

According to the Dhaka-based Business Post, one of the patients is a 38-year-old man who was admitted to a hospital in Manikganj district on January 16. Two days later, when his condition worsened, he was transferred to a hospital in Dhaka, where his Nipah virus infection was confirmed. The other patient is a 27-year-old man from the same district who was initially treated with products from a local pharmacy after his symptoms began and was hospitalized in Dhaka after his condition deteriorated.

Bangladesh reported 14 cases in 2023, 10 of them fatal, putting the country's deaths from the virus at their highest level in 5 years. Nipah virus infections have a high case-fatality rate, between 45% and 75%. There are no approved treatments or vaccines, and the World Health Organization has designated it a priority disease for research and development. The Coalition for Epidemic Preparedness Innovations has also prioritized Nipah virus for countermeasure development.

NIH-funded study to evaluate impact of environmental factors on infant microbiome

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Rutgers Health announced last week that it has received $3.1 million from the National Institutes of Health (NIH) to launching a new research project on the impact of environmental factors on the infant microbiome.

The project, part of NIH's Environmental Influences on Child Health Outcomes (ECHO) program, will recruit 500 pregnant women and follow them, their partners, and their children for up to 7 years to examine how environmental exposures affect the development of the infant microbiome, and what impact that has on child health. Rutgers Health researchers will specifically look at upper and lower respiratory health—one of the five key pediatric outcomes evaluated in the ECHO program—in relation to the microbiome.

Among the exposures they'll be assessing is antibiotic use, which has been shown to disrupt the microbiome. Antibiotic exposure during infancy has been associated with reduced gut microbiome diversity in previous studies.

"We will be characterizing the disparities in common exposures that disturb the microbiome, such as Caesarean sections, formula feeding and antibiotic use, during the critical early developmental periods—re-conception, pregnancy, delivery, infancy and early childhood—and evaluate associations with longitudinal microbiome structures in mothers and children," principal investigator Martin Blaser, MD, director of the Rutgers Center for Advanced Biotechnology and Medicine, said in a press release.

The project will also evaluate the role of different social determinants of health on developing children.

High rate of healthcare-associated infections, broad-spectrum antibiotic use reported in Greek hospitals

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A 2022 point-prevalence survey (PPS) in Greek hospitals found rising rates of healthcare-associated infections (HAIs), high resistance to first-line antibiotics, and extensive use of broad-spectrum antibiotics, researchers reported last week in Antimicrobial Resistance and Infection Control.

The cross-sectional study, conducted in 50 of the 126 hospitals of the Greek National Health Care system from October through December 2022, collected data on HAIs and antibiotic use among patients admitted before 8:00 am on the day of the survey. In a 2016-2017 PPS conducted by the European Centre for Disease Prevention and Control, Greece was among the countries with the highest prevalence of HAI (10%) and antibiotic use (55.6%).

Of the 9,707 inpatients included in the study, 1,175 (12.1%) had an HAI and 5,376 (55.4%) were receiving at least on antibiotic. Lower respiratory tract (28.9%), bloodstream (20%), and urinary tract infections (13.1%) were the most common HAIs. Intensive care unit patients had the highest HAI (45.7%) and antibiotic use (71.3%) prevalence. Gram-negative bacteria were the most frequent source of HAIs (58.4% of total isolates), with Klebsiella (20.5%) and Acinetobacter (12.8%) the most frequently identified. The prevalence of resistance to first-level antibiotic markers was 69.3%.

Extensive use of broad-spectrum antibiotics

Among the 9,003 antimicrobials recorded, piperacillin-tazobactam (10.9%) and meropenem (7.7%) were the most frequently prescribed, and the ratio of broad-spectrum to narrow-spectrum antibiotics was 1.4. As defined by the World Health Organization's AWaRe (Access, Watch, and Reserve) classification system, Watch and Reserve antibiotics constituted 76.7% of all antibiotics prescribed. The WHO suggests that at least 60% of antibiotics consumed at the national level come from the Access group.

"The 2022 PPS study highlights the significant challenge that HAIs pose in patient care in Greece," the study authors wrote. "It clearly indicates an increased burden of HAIs together with the emergence of difficult-to-treat pathogens in inpatients, as well as the extensive use of broad-spectrum antimicrobials."

The authors say strengthening infection prevention and control and antimicrobial stewardship in these settings is essential.

The 2022 PPS study highlights the significant challenge that HAIs pose in patient care in Greece.

Study: Cognitive slowing is associated with long COVID

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Woman with headacheIn an attempt to establish a definitive objective cognitive marker for PCC, or post-COVID-19 condition, researchers tested long COVID patients in Germany and the United Kingdom with cognitive speed tests, and found long COVID patients have a significant lag, suggesting cognitive slowing.

The study, published yesterday in eClincialMedicine, was based on findings on an initial 194 long COVID patient seen at a PCC clinic in Germany. Findings were then replicated in a follow up COVID clinic in the United Kingdom.

All study participants had one or more symptoms of PCC at least 12 weeks following a lab-confirmed COVID-19 infection. They were compared to two control groups, one group that had never had a COVID-19 infection and one group that had COVID-19 12 or more weeks prior but no evidence of PCC.

Cases and controls completed the same series of computer-based cognitive tests, which measured reaction time and number vigilance. They also completed questionaries about perceived PCC symptoms and mental health.

No association between mental health and cognitive slowing

The average reaction time (RT) for healthy controls (both no-COVID and no-PCC groups) was 0.34 seconds, but patients with PCC responded significantly more slowly, with a mean of 0.49 seconds, the authors said.  More than half (53.5%) of patients with PCC had a response speed slower than 2 standard deviations from the control mean.

The present study reported a significant psychomotor slowing in individuals diagnosed with PCC.

There was not a significant correlation between the severity of mental health symptoms and chronic post-COVID cognitive deficit.

"The present study reported a significant psychomotor slowing in individuals diagnosed with PCC," the authors said. "This might be an important factor contributing to some of the cognitive impairments reported in patients with PCC."

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