Lab study: Sterilized reused respirators not effective enough against aerosolized particles

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Stack of respirators
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Less than 20% of reused filtering facepiece respirators (FFRs) collected from nurses amid the COVID-19 pandemic were in good enough condition to undergo sterilization, after which none retained at least 94% filtration of aerosol particles, finds a laboratory study comparing two sterilization methods after up to 15 to 30 days of use.

For the study, published in the American Journal of Infection Control, a University of Sao Paulo-led team in Brazil used a chambered box and an emitted aerosol to evaluate the physical characteristics and post-sterilization filtration of a 5-centimeter (2-inch) square fragment from each of 100 reused FFRs (eg, N95s) collected from nurses who cared for COVID-19 patients at three hospitals. 

Untorn respirators that filtered at least 94% of aerosolized particles and had an attached nasal clip and elastic bands and no visible dirt were randomly assigned to receive or not receive mechanical cleaning with an ultrasonic washer before undergoing hydrogen peroxide plasma gas sterilization.

"During the COVID-19 pandemic, there was a shortage of Filtering Facepiece Respirators (FFR), leading to prolonged use and reuse of FFRs," the authors noted. "There was also an effort to sterilize FFRs aiming to increase the safety of healthcare professionals as it was thought that sterilization could reduce self-contamination and protect the environment from excess contaminated waste."

Over 78% of FFRs were too dirty to sterilize

Of the 1,055 FFRs, over 85% retained secured nose clips, preserved strap elasticity, and no tears. But over 78% of samples were dirty (eg, from makeup), leaving only 19.6% eligible to undergo sterilization. None of the FFRs—cleaned or uncleaned—reached minimum filtration after sterilization, although 72% of the uncleaned FFRs and 80% of the cleaned devices achieved 90.0% to 93.9% filtration.

Sterilization processes using hydrogen peroxide plasma gas, both with and without prior cleaning, applied to 100 FFRs with preserved functionality, did not compromise the apparent physical characteristics of these respirators, but did not maintain their filtration levels to the minimum necessary to be considered safe.

"Sterilization processes using hydrogen peroxide plasma gas, both with and without prior cleaning, applied to 100 FFRs with preserved functionality, did not compromise the apparent physical characteristics of these respirators, but did not maintain their filtration levels to the minimum necessary to be considered safe," the researchers concluded.

Michigan announces financial assistance for dairy farms to help with H5N1 research

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The Michigan Department of Agriculture and Rural Development (MDARD) today announced funding for up to 20 avian flu outbreak dairy farms, at up to $28,000 per farm, to participate in crucial, real-time research studies.

cows feeding
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In a statement, MDARD Director Tim Boring, PhD, said the money is in addition to earlier support announced by the US Department of Agriculture (USDA) and that eligible farms would work with MDARD and the USDA's Animal and Plant Health Inspection Service to complete epidemiologic investigations, participate in real-time longitudinal studies, and engage with Michigan Department of Health and Human Services programs, if applicable.

Michigan has drawn praise for its transparency and response activities regarding H5N1 highly pathogenic avian influenza (HPAI) outbreaks on dairy and poultry farms. "Our HPAI-impacted farms have been incredibly cooperative in Michigan s One Health approach to combat this disease," Boring said. "The research opportunities through this package will help us advance science in real-time to best develop our continued rapid response."

More outbreaks in Iowa, Minnesota

In other H5N1 developments, Iowa yesterday reported another H5N1 outbreaks in a dairy herd, another from Sioux County. Also, Minnesota reported three more outbreaks in dairy herds, all in counties in the central part of the state: Benton, Kandiyohi, and Morrison.

Mpox spreads to another DR Congo province

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An mpox outbreak in the Democratic Republic of the Congo (DRC) continues to spread within the country, with the first case reported in North Kivu province, according to a recent update from the World Health Organization (WHO).

mpox lesions
CDC/ Brian W.J. Mahy

The DRC's outbreak began in late 2022 and involves the clade 1 mpox virus, which is different from the clade 2 strain circulating globally. The outbreak is notable, because it is the first in Africa—where much of the disease activity has been related to zoonotic spread—to involve sexual spread.  One of the country's hot spots has been Kamatuga in South Kivu province, where a novel clade 1 virus emerged with mutations that make the virus more adapted to circulation among humans. Sequencing suggests, however, that viruses from other parts of the country don't have the mutations.

The case in North Kivu province involves a 19-year-old woman whose illness was confirmed in Goma on June 1. Investigators found that she had sexual contact with a person with a suspected infection who had been in South Kivu province. 

So far in 2024, 7,851 mpox cases have been reported in the DRC, 384 of them fatal. With the case from Noth Kivu province, illnesses have now been reported in 23 of the country's 26 provinces. The disease is spreading through various contact forms, including sexual, nonsexual, household, and healthcare.

Children are still the most affected age-group, with 39% of cases in kids younger than 5 years old. The disease was fatal in 240 of those cases. 

Outbreak in South Africa, case rise in Los Angeles

South Africa recently reported an mpox outbreak involving the clade 2 virus responsible for global spread. So far, seven cases have been reported, according an update from the Africa Centres for Disease Control and Prevention. The country also reported its first two mpox deaths. All cases were severe and involved men ages 30 to 39 who had underlying health conditions such as HIV. So far, investigations have found the patients hadn't traveled to countries that have ongoing outbreaks.

In the United States, the Los Angeles Department of Public Health yesterday posted an alert about a rise in mpox cases, with 10 illnesses reported in the past 2 weeks. For comparison, it said during the previous several weeks it was averaging about 2 cases a week. It urged people in risk groups to take precautions and to get vaccinated. 

Data suggest hybrid immunity protects against long COVID

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A study yesterday in the Journal of Infection shows that hybrid immunity from both a fourth vaccination dose and previous COVID-19 illnesses may offer protection against developing long COVID, or post-COVID condition (PCC). 

The study is based on 109,707 participant surveys collected about health history and self-reported post-infection symptoms in the German National Cohort. More than 80% of the participants had received three or more COVID-19 vaccinations. 

Of the 60% of participants who said they had had a previous COVID-19 infection, 35% reported persistent symptoms 4 to 12 months after infection. Of those, 23% reported "high PCC," which means nine or more symptoms. 

Omicron associated with less long COVID

Virus variant type had the greatest influence on developing long COVID. "Any PCC occurred in around 7% after an infection during the Omicron phase for those with a previous infection and in 47% after initial infection with the Wildtype virus," the authors wrote. 

The risk of developing any PCC after a second infection if PCC did not follow a first infection was substantially lower compared to after the first infection, resulting in a long-term risk reduction of around 50%, the authors said. 

But the risk of developing long COVID was higher in people who were infected less than 3 months following a vaccination, but approximately 50% compared to those who were infected 4 to 6 months after vaccination. 

Our findings indicate that the risk of developing PCC was strongly reduced for the second SARS-CoV-2 infection

"Our findings indicate that the risk of developing PCC was strongly reduced for the second SARS-CoV-2 infection, if the first infection did not result in PCC," the authors concluded. "It is possible that the occurrence of breakthrough infections shortly after vaccination is linked to a specific vulnerability of the individual towards PCC, and the apparent protection actually results from confounding."

Study: VA flu vaccine mandate for health workers successful

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flu shot
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Almost all—96%—of Veterans Administration (VA) hospitals and 74% of hospitals serving the general population currently require staff to get seasonal influenza vaccines, according to a recent research letter in JAMA Network Open. 

The percentage of US hospitals requiring vaccination or an exemption has risen in recent years, the study authors said, and illustrates the impact of the 2020 Veterans Health Administration directive requiring flu vaccines or annual waivers as conditions of employment. 

The study was based on hospital surveys in 2017 and 2021, sent to 881 nonfederal general medical and surgical hospitals with intensive care units and all 127 VA hospitals. 

Mandate began in 2020

For non-federal hospitals, vaccine requirements increased from 69% (365 of 526) in 2017 to 74% (299 of 405) in 2021. But in VA hospitals, mandatory flu vaccinations increased significantly, from 4% (3 of 73) in 2017 to 96% (63 of 66) in 2021.

The findings suggest that vaccine mandates, which have been oft-debated since the COVID-19 pandemic began, may not be as controversial as thought.

There will always be vaccine hesitancy and concerns about bodily autonomy among health care workers, and seasonal flu vaccine effectiveness is variable.

"There will always be vaccine hesitancy and concerns about bodily autonomy among health care workers, and seasonal flu vaccine effectiveness is variable," said Todd Greene, MD, MPH, of Michigan Medicine in a University of Michigan press release. "But for people working in the care environment, the benefits of getting vaccinated will generally outweigh any potential risks."


 

Novel antifungal candidate gets financial boost

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Biotechnology company Elion Therapeutics of New York City announced yesterday that it has closed an $81 million funding round to advance development of its next-generation polyene antifungal candidate, SF001.

SF001 is a novel analog of the antifungal amphotericin B that's been designed to reduce systemic toxicities and has demonstrated potent in vitro fungicidal activity and in vivo efficacy. In 2023, the compound received Qualified Infectious Disease Product and Fast Track designations from the US Food and Drug Administration for early antifungal therapy of presumed invasive fungal infection (IFI) and treatment of invasive aspergillosis.

Amphotericin B is a widely used, broad-spectrum polyene antifungal, but its use is associated with kidney toxicity.

Rising levels of invasive fungal infections

"Invasive fungal infections have reached historic levels of concern, largely due to increased medical reliance on biologic immunosuppression, more people with severe pulmonary disease at risk of IFI, and increased exposures associated with environmental changes," Kieren Marr, MD, MBA, Elion's president and chief medical officer, said in a company press release. "As we move into the next stage of our clinical program, we're optimistic about the potential of SF001 to deliver antifungal treatment with reduced toxicity and the potential to address critical challenges with currently available options."

The $81 million funding round includes investments from the AMR Action Fund, a public-private partnership established in 2020 to provide financial and technical support to small biotech companies developing novel antibiotics. It's the fund's first investment in an antifungal company.

"With resistance to existing antifungals growing and infection rates increasing, it is essential that we develop effective therapies for patients in need," said AMR Action Fund CEO Henry Skinner, PhD, MBE. "We are pleased to support the team at Elion and believe their work could deliver an important treatment for patients suffering from devastating fungal infections."

Quick takes: Pandemic unreadiness, 21-strain pneumococcal vaccine, chikungunya vaccine submission

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  • Amid increased H5N1 avian flu circulation in mammal populations and mpox deaths in African children, the world hasn't done enough to prepare for its next pandemic threat, an independent group that reviewed the world's COVID response for the World Health Organization (WHO) said today. In a report that takes stock of progress on its earlier recommendations, the Independent Panel for Pandemic Preparedness and Response said world leaders have turned away from pandemic preparedness, leading to a gamble with the world's future. They said funding for pandemic preparedness pales compared to needs and that high-income countries are too tightly bound to charity-based approaches. They noted some causes for hope, however, such as recent amendments to the International Health Regulations by the World Health Assembly and a decision in 2023 to increased unearmarked funding to the WHO's base budget. Among their recommendations, they urged member states to make progress on the pandemic agreement and adopt it by December 2024.
  • Merck yesterday announced that the US Food and Drug Administration (FDA) has approved its 21-valent conjugate vaccine for preventing invasive pneumococcal disease and pneumococcal pneumonia in adults. The vaccine, called Capvaxive, was assessed under FDA priority review, which included four phase 2 studies that found robust immune response in vaccine-naïve and vaccine-experienced populations. In a statement, the company said the vaccine is intended for adults and covers serotypes that are responsible for 84% of invasive pneumococcal disease in people ages 50 and older. It includes eight serotypes that aren't included in other currently approved pneumococcal vaccines. The Centers for Disease Control and Prevention vaccine advisory group is expected to weigh in with a recommendation for use of the vaccine next week.
  • Bavarian Nordic yesterday announced that it has completed the rolling submission process to the FDA for its candidate chikungunya vaccine. The virus-like particle vaccine is given as a single dose, and the company said it would be made in prefilled syringes. Bavarian Nordic said the vaccine is indicated for people ages 12 and older and that the licensing application is the first against the virus for adolescents. The submission paves the way for potential approval in the first half of 2025. If approved, it would be the FDA's second for a chikungunya vaccine. In November 2023, the FDA approved Valneva's chikungunya vaccine for use in adults.

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