Maternal exposure to zinc oxide nanoparticles causes cochlear dysfunction in the offspring.

Introduction: Zinc oxide nanoparticles (ZnO NPs) have been engineered and are largely used in material science and industry. This large and increasing use justifies a careful study about the toxicity of this material for human subjects. The concerns regard also the reproductive toxicity and the fetotoxicity. Materials and methods: The effect of the exposure to ZnO NPs on the cochlear function was studied in a group of pregnant CD1 mice and in their offspring. This study is part of a larger toxicological study about the toxicity of ZnO NPs during pregnancy. Four groups were analyzed and compared, exposed and non-exposed dams and their offspring. The cochlear function was quantitatively assessed by means of Distortion Product Otoacoustic Emissions (DPOAEs). Results and discussion: A large statistically significant difference was found between the non-exposed dams offspring and the exposed dams offspring (p = 1.6 · 10-3), whose DPOAE levels were significantly lower than those of non-exposed dams offspring and comparable to those of the adults. The DPOAE levels of the exposed and non-exposed dams were very low and not significantly different. This occurrence is related to the fact that these mice encounter a rapid aging process. Conclusion: Our findings show that maternal exposure to ZnO NPs does not reflect in overt toxicity on fetal development nor impair offspring birth, however it may damage the nervous tissue of the inner ear in the offspring. Other studies should confirm this result and identify the mechanisms through which ZnO NPs may affect ear development.

Pulmonary function assessment after COVID-19 in vaccinated healthcare workers.

COVID-19 typically presents with flu-like symptoms due to the viral infection itself. The most severe cases are characterised by lung damage, an important factor in fatal outcome due to alveolar damage. In some cases, patients develop a long COVID with persistent symptoms of chest pain and fatigue. Causes, including organ damage or inflammation, are being investigated. Clinical outcomes are variable and permanent lung damage is not fully understood, while vaccination is effective against severe infection but its effect on respiratory function in mild cases remains uncertain. This retrospective study aims to analyse changes in lung function in HCWs who had COVID-19 between 2020 and 2022, comparing their spirometric test results before and after the pandemic and taking into account their vaccination status. 321 HCWs were included in the study. The study examined spirometric parameters both before and after the pandemic, and all measured outcomes except the FEV1/FVC ratio showed a significant decrease during the study period. We then assessed the association between SARS-CoV-2 infection and changes in lung function parameters, analysing infections in 2020, 2021 and 2022 separately. We found a statistically significant difference in Forced vital capacity (FVC) between infected and non-infected subjects in 2020 and 2021, but not in 2022. To evaluate the protective effect of SARS-CoV-2 vaccination on respiratory function, a linear regression analysis was performed using changes in FVC, Forced expiratory volume in 1 s (FEV1), FVC/FEV1 ratio and Peak expiratory flow (PEF) as dependent variables. The analysis showed that the decline in FVC was significantly lower in subjects who had been vaccinated prior to infection. The study concludes that subclinical SARS-CoV-2 infections in 2020 and 2021 worsened respiratory parameters (FVC and FEV1), but vaccination protected against these effects. Even healthy individuals with previous infections showed respiratory changes, with vaccination providing protection, especially for FVC decline. This highlights the importance of vaccinating healthcare workers against COVID-19.

The BNT162b2 mRNA COVID-19 Vaccine Increases the Contractile Sensitivity to Histamine and Parasympathetic Activation in a Human Ex Vivo Model of Severe Eosinophilic Asthma.

The BNT162b2 COVID-19 vaccine is composed of lipid-nanoparticles (LNP) containing the mRNA that encodes for SARS-CoV-2 spike glycoprotein. Bronchospasm has been reported as an early reaction after COVID-19 mRNA vaccines in asthmatic patients. The aim of this study was to investigate the acute impact of BNT162b2 in a human ex vivo model of severe eosinophilic asthma. Passively sensitized human isolated bronchi were challenged with the platelet-activating factor to reproduce ex vivo the hyperresponsiveness of airways of patients suffering from severe eosinophilic asthma. BNT162b2 was tested on the contractile sensitivity to histamine and parasympathetic activation via electrical field stimulation (EFS); some experiments were performed after mRNA denaturation. BNT162b2 increased the resting tone (+11.82 ± 2.27%) and response to histamine in partially contracted tissue (+42.97 ± 9.64%) vs. the control (p < 0.001); it also shifted the concentration-response curve to histamine leftward (0.76 ± 0.09 logarithm) and enhanced the response to EFS (+28.46 ± 4.40%) vs. the control. Denaturation did not significantly modify (p > 0.05) the effect of BNT162b2. BNT162b2 increases the contractile sensitivity to histamine and parasympathetic activation in hyperresponsive airways, a detrimental effect not related to the active component but to some excipient. A possible candidate for the bronchospasm elicited by BNT162b2 could be the polyethylene glycol/macrogol used to produce LNP.

Global Policy to Reduce the Incidence of Infection Spreading in Non-Vaccinated Healthcare Workers: A Literature Review.

Healthcare workers (HCWs) are at increased risk of SARS-CoV-2 infection because of their occupational exposure. Moreover, they can be a vehicle for the virus transmission among patients. The vaccination of healthcare personnel against COVID-19 is crucial in fighting the spread of SARS-CoV-2 infection, together with strict sanitary procedures that aim to limit the risk of contagion. Unfortunately, even if COVID-19 vaccination has been proved one of the most effective tools for protecting against COVID-19, many healthcare professionals are not yet vaccinated. The aim of the current review is to contribute to identifying an effective strategy for COVID-19 prevention especially among non-vaccinated HCWs. In this review, we collected the most recent and relevant findings from literature on the protection of unvaccinated HCWs, identifying three types of measures as principal actions to protect those operators: addressing vaccine hesitancy, improving non-pharmaceutical interventions and promoting actions at personal level (respiratory hygiene, hand hygiene and use of PPE). All these interventions are very effective in preventing contagion, if well respected and conducted; nevertheless, it is essential to promote vaccination, as it is the most effective measure.

Contact Screening for Healthcare Workers Exposed to Patients with COVID-19.

In China and Italy, many cases of coronavirus disease 2019 (COVID-19) have occurred among healthcare workers (HCWs). Prompt identification, isolation and contact tracing of COVID-19 cases are key elements in controlling the COVID-19 pandemic. The aim of this study was to evaluate the rate of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection among HCWs exposed to patients with COVID-19 in relation to the main determinants of exposure. To assess the risk of exposure, we performed active symptom monitoring in 1006 HCWs identified as contacts of COVID19 cases. The presence of symptoms was statistically associated with a positive nasopharyngeal swab result. Only one subject was asymptomatic at the time of positive test. These data suggest that clinical history may help in the selection of subjects to be investigated by means of reverse transcriptase-polymerase chain reaction (RT-PCR) in the case of a shortage of diagnostic resources. We found that close contact (within 2 m for 15 min or more) was not statistically related to contagion. Regarding the use of personal protective equipment (PPE), only the use of facial masks was inversely related to the chance of becoming infected (p < 0.01). In conclusion, our data show that unprotected contacts between HCWs should be considered a major route of HCW contagion, suggesting that the use of facial masks should be implemented even in settings where known patients with COVID-19 are not present.