Protective role of SARS-CoV-2 anti-S IgG against breakthrough infections among European healthcare workers during pre and post-Omicron surge-ORCHESTRA project.

PURPOSE: Anti SARS-CoV-2 vaccination initially showed high effectiveness in preventing COVID-19. However, after the surge of variants of concern, the effectiveness dropped. Several studies investigated if this was related to the decrease of the humoral response over time; however, this issue is still unclear. The aim of this study was to understand whether SARS-CoV-2 anti-S IgG levels can be used to predict breakthrough infection risk and define the timing for further booster doses administration. METHOD: Within the framework of the ORCHESTRA Project, over 20,000 health workers from 11 European centers were enrolled since December 2020. We performed two Cox proportional hazards survival analyses regarding pre-Omicron (from January to July 2021) and Omicron (December 2021-May 2022) periods. The serological response was classified as high (above the 75th percentile), medium (25th-75th), or low (< 25th). RESULTS: Seventy-four (0.33%) and 2122 (20%) health workers were infected during the first and second periods, respectively. Both Cox analyses showed that having high anti-S titer was linked to a significantly lower risk of infection as compared to having medium serological response [HR of high vs medium anti-S titer = 0.27 (95% CI 0.11-0.66) during the first phase, HR = 0.76 (95% CI 0.62-0.93) during the second phase]. CONCLUSION: Vaccine effectiveness wanes significantly after new variants surge, making anti-S titer unsuitable to predict optimal timing for further booster dose administration. Studies on other immunological indicators, such as cellular immunity, are therefore needed to better understand the mechanisms and duration of protection against breakthrough infection risk.

Occupational Exposure to Solar Radiation and the Eye: A Call to Implement Health Surveillance of Outdoor Workers.

Globally, hundreds of millions of outdoor workers are exposed to solar radiation (SR) for the majority of their working life. Such occupational exposure is known to induce various adverse health effects to the eyes, mainly related to its ultraviolet (UV) component. The present work is a call-to-action aimed at raising the awareness on the need of health surveillance for the prevention of the chronic ocular diseases in outdoor workers. Photo-chemical chronic damage can induce pterygium at the outer layer of the eye and cataract in the lens. Considering carcinogenic effects, rare squamous-cells tumors of the cornea and/or of the conjunctiva and the ocular melanomas are associated with UV radiation exposure. Solar UV-related eye diseases should be considered as "occupational diseases" when there is sufficient exposure in workers, but they are often not recognized, and/or frequently not reported to the national compensation authorities. Therefore, to prevent the burden of these work-related eye pathologies, an adequate risk assessment with identification of appropriate preventive measures, and a provision of periodic health surveillance to the exposed workers, in particular considering those at higher risk of exposure or with individual susceptibility, should be urgently implemented.

[The development of the new guidelines of the Italian association of medical radioprotection (AIRM) for the protection of the workers exposed to EMF related risks: new approaches and criteria]. / Il percorso verso nuove linee guida AIRM per la protezione dei lavoratori dal rischio da campi elettromagnetici: criteri e novità.

SUMMARY: An up-to-date knowledge on the occupational risk related to electromagnetic fields (EMF) exposure and its prevention, and on the criteria and methods for an appropriate health surveillance (HS) of exposed workers are highly important, as: EMF are almost ubiquitous; in recent years, relevant changes and advancements in the technologies applied have been observed, e.g. the introduction of new equipment for Magnetic Resonance, involving potentially higher exposures for operators, and the development of the 5G technology, using also EMF bands with millimetric wavelengths, not often applied previously; in Italy the new Legislative Decree 159/2016 has been promulgated, implementing the Directive 2013/35/EU and, accordingly, introducing several substantial changes to the Legislative Decree 81/2008 on safety and health at work, in particular to its fourth chapter of the eight section ("Physical Agents"), entitled "The protection of workers from the risks related to electromagnetic fields exposure". For these reasons, the Italian Association of Medical Radioprotection (AIRM) has fully revised the "Guidelines for the health surveillance of workers exposed to non-ionizing radiation", published in 2012 together with the Italian Society of Occupational Medicine (SIML). Therefore, AIRM involved a multidisciplinary panel of experts, working in accordance to a rigorous scientific methodology, based on the recognized international indications for the development of guidelines (GL) in the medical field, as those proposed by the Guidelines International Network (GIN), the Grading of Recommendations Assessment, Development and Evaluation (GRADE), the National Institute for Health and Care Excellence (NICE) and the Appraisal of Guidelines for Research and Evaluation (AGREE) collaboration. Furthermore, the multidisciplinary panel conducted a systematic review of the scientific literature according to the "Preferred Reporting Items for Systematic Reviews and Meta-Analyzes" (PRISMA) criteria, aimed at answering to specific research questions, including the "PECO" (Populations of interest, Exposures, Comparators, and Outcomes) questions. The final stages of the GL include the revision of the GL-draft from an external group of independent experts, giving also an overall evaluation and opinions on the Recommendations elaborated, so that the panel group can elaborate a final document to be shared again, after agreement among all the experts, with a consensus reached by Delphi method in case of disagreement. The main GL objective is to guide occupational physicians in charge for the HS of EMF exposed workers, providing up-to-date indications on the contents and methods for an adequate HS of the workers, but also on the regulations and standards applicable, on the relevant occupational EMF exposure sources, on the possible adverse effects to be considered, including indications on the biological mechanisms involved, on the conditions of particular susceptibility to the EMF risk, on the criteria to be considered for the evaluation of "fitness to work" in case of occupational EMF exposure and finally also on the contents of adequate information and training for the workers exposed. As a final objective, the AIRM GL on HS of workers exposed to EMF will be proposed for public consultation to the Italian National Guidelines System, as required according to the Law n. 24/2017, also known as the «Gelli law¼.

[Occupational risk related to natural optical radiation exposure and skin cancers]. / Rischio di tumore cutaneo da esposizione a radiazioni ottiche naturali.

SUMMARY: Skin tumors are the most frequent neoplasms worldwide in Caucasian subjects, and UV exposure is one of the most relevant risk factors in their etiology. Cumulative UV exposure is strongly associated with an increased occurrence of both basal and squamous cell carcinomas (i.e. Non melanoma skin cancers - NMSC), while for malignant melanoma the role of UV radiation as risk factors seems more related to intermittent and intense exposures, able to induce repeated sunburns, at young ages. Considering the occupational risk, currently UV radiation, part of the solar radiation (SR) spectrum, is one of the major risks in all jobs including outdoor activities (outdoor work - OW): many studies show high levels of solar UV exposure during OW, nevertheless to date the European, and Italian, legislation on occupational risks prevention does not include specific requirements for SR compleexposure at work, as occupational exposure limits values or workers' health surveillance. This is not coherent with the strong associations showed in scientific literature in particular between the occurrence of NMSC and a history of OW. Accordingly, considering the high exposure levels, the large number of outdoor workers and the strong associations with NMSC, we'd expect a relevant number of occupational skin cancers (OSC) to be reported every year to the national workers' compensation authorities in European countries. Nevertheless, in Italy, as in other European countries, the number of reported UV-induced OSC is much lower than the expected number of OSC, with less than 40 cases reported on average in Italy in last years compared to about a thousand of expected cases incident in outdoor workers per year. An increasing in the reporting of OSC would certainly be important, for the purpose of a better recognition of the real dimension of the phenomenon, and to stimulate the implementation of adequate preventive strategies, in order to guarantee an improved protection of outdoor workers and a more appropriate prevention of the adverse health effects related to solar UV exposure.

Sun protection habits and behaviors of a group of outdoor workers and students from the agricultural and construction sectors in north-Italy.

BACKGROUND: Despite the relevant frequency of ultraviolet induced adverse health effects in workers, solar ultraviolet radiation (UVR) exposure is an occupational risk not adequately minimized in Italy. OBJECTIVE: To assess the characteristics and prevalence of sun exposure habits and behaviors in a group of students and outdoor workers (OW) from the agricultural and construction sectors of a north-Italian region. METHODS: Based on a previously developed standardized questionnaire, we collected full information on individual sun exposure habits at work and during leisure activities. RESULTS: In 2018, 380 high school students and OW from the agricultural and construction sectors participated in a sun-safety campaign. More than a third (39.0%) of OW reported never using sunglasses, 52.8% never applied sunscreens at work, and a quarter never wear a UV protective hat. Considering leisure-time, students reported more frequent sunburns compared to OW: 25.0% vs. 13.8%; half (51.6%) of students and a third (36.4%) of OW reported never wearing a UV protective hat. A third (30.1%) of students and 37.2% of OW never or only seldom applied sunscreens on holidays. DISCUSSION: The majority of OW in our study reported poor protective solar exposure habits. Young students of the construction and agricultural sectors indicated even worse sun-protective behaviors, both during apprenticeship and leisure activities. Our study highlights the low health literacy related to solar UVR in OW and apprentices. Further educational initiatives are required in Italy to improve the adoption of protective behaviors during outdoor activities.

Risk of cataract in health care workers exposed to ionizing radiation: a systematic review.

BACKGROUND: The eye is an important sensory organ occupationally exposed to ionizing radiation (IR) in healthcare workers (HCWs) engaged in medical imaging (MI). New evidence highlights the possible induction of cataract at IR exposure levels to be much lower than expected in the past. OBJECTIVE: Conduct an updated review on the current evidence on cataract risk in healthcare workers exposed to IR. METHODS: Published scientific studies on cataract risk in IR exposed healthcare workers were collected through a systematic search of two biomedical databases (MEDLINE and Scopus). Data from included studies was extracted and summarized. Study quality was also assessed. RESULTS: All 21 eligible studies reported an increased prevalence of cataract, especially posterior subcapsular cataract, in IR exposed  HCWs with a higher prevalence in interventional cardiology staff. DISCUSSION: Our review synthesizes the latest evidence to support the hypothesis of a significantly increased risk of occupational cataract in healthcare workers operating MI and exposed to IR, especially in interventional cardiologists. Data also support a dose-response relationship between IR exposure and the prevalence of opacities, especially posterior subcapsular opacities. CONCLUSIONS: Findings highlight the need for effective control measures including appropriate training, adherence to protective procedures, and a constant use of shields and eye personal protective equipment in healthcare workers with optical exposure to IR. Periodic health surveillance programs, possibly including lens evaluation, are also important to monitor cataract risk in these MI operators.

Macular degeneration and occupational risk factors: a systematic review.

PURPOSE: Macular degeneration is a multi-factorial disease, leading cause of blindness for people over 50 years old in developed countries. To date, the knowledge on possible occupational factors involved in the development of the disease is scant. METHOD: We performed a systematic scientific literature search on the association between macular degeneration and occupational risk factors searching the MedLine and Scopus databases. RESULTS: We examined 158 articles and, according to the inclusion criteria, 13 peer-reviewed studies evaluating occupational risk factors for macular degeneration or reporting the frequency of the disease in specific groups of workers were included in the review. Ten on thirteen articles evaluated the presence of macular degeneration in workers exposed to solar radiation. Only one study found that non-specific history of occupational chemical exposure was associated with the disease. Two studies showed an association between macular degeneration and the general category of "blue-collar" workers, but they did not identify the specific risk factors involved. CONCLUSIONS: To date few studies have examined occupational risk factors for macular degeneration. Nevertheless, available data indicate that long-term occupational solar radiation exposure, in particular for its blue-light component, is associated with macular degeneration in outdoor workers.

[Health surveillance of EMF-exposed workers at particular risk.] / Metodi e strumenti sanitari per l'idoneità lavorativa dei soggetti particolarmente sensibili a CEM.

SUMMARY: Present knowledge on the conditions possibly inducing a particular sensitivity to EMFs, and the relevant mechanisms involved, are presented and discussed. On the basis of the knowledge presented, the criteria that should be applied for the health surveillance of the workers in whom these conditions have been identified, are discussed.

Stakeholders' views on vocational rehabilitation programs: a call for collaboration with Occupational Health Physicians.

BACKGROUND: The triple-dip recession taking place in Italy in 2008-2014 impacted negatively on health, mainly by increasing the rate of unemployment. This increased the prevalence of mental health disorders, while reducing the number of available places on vocational rehabilitation programs (VRPs) delivered by the psychiatric services. OBJECTIVES: To explore the different points of views of stakeholders (namely, users and professionals) involved in VRPs developed inside an Italian Community Mental Health Center (CMHC). METHODS: A sample of users, psychiatrists, educators and nurses of an Italian CMHC involved in VRPs took part in a focus group. Content analysis was performed with MAXQDA 12, by developing a hierarchical code system a posteriori (i.e., derived from the data). The respondent validation phase was carried out by means of a multiple-choice questionnaire, administered to all participants. RESULTS: A total of 86 emerging issues were coded, divided into two macro-areas: Positive and Negative Reinforcements (48 contributions, 56%, and 38 contributions, 44%, respectively), further subdivided into three areas: professional (service) factors, personal (i.e, user-related) factors, and work environment features (including relationships in the workplace). Some contributions raised issues concerning occupational health protection (e.g. need of information about the rights and duties of the users-workers, as well as the risks they are exposed to in the workplace). CONCLUSIONS: The analysis suggested to address specific issues concerning work and VRPs by means of psycho-education group interventions currently carried out at CMHCs, and pointed to the need to foster collaboration between mental health professionals and the occupational health physician of the company where the VRP is started and where the user might be employed.

The biomechanical overload of the upper limb: a neglected occupational hazard in animal facility operators.

Data on biomechanical overload of the upper limb in animal facility operators are currently scanty. We decided to study this risk in a university animal facility. Eleven different tasks performed by operators were identified. For each of them, the biomechanical overload of the upper limb was evaluated by applying 4 different methods frequently used, hypothesising a task duration of 4 and 8 h. Then two 'typical' real working days of the examined facility were reconstructed, and the risk for operators was calculated using the OCRA Index, Checklist and Mini-Checklist. Considering the specific tasks, the results show some difference among methods, but the overall results show an acceptable/slight risk of biomechanical overload of the upper limb in animal facility operators during typical working days. Practitioner Summary: Upper limb biomechanical overload (UL-BO) is a neglected risk in animal facilities. In a university facility, 11 different tasks were identified, and 2 typical working days were analysed. Even if some task at increased risk may exist, during typical working days,  the overall results show that the risk of UL-BO in operators can be considered usually acceptable or, at worst, slight.

Subjective symptoms in Magnetic Resonance Imaging operators: prevalence, short-term evolution and possible related factors.

BACKGROUND: The number of Magnetic Resonance Imaging (MRI) operators is rapidly increasing. In these workers, a high prevalence of certain subjective symptoms has been described but until now scant research is available on this topic. OBJECTIVES: To assess the prevalence and the evolution of symptoms over time in a group of operators recently engaged in MRI, also considering the possible role played by factors such as age, gender and occupational stress. METHODS: In 17 physicians exclusively engaged in MRI - 6 working with 1.5 T scanners only and 11 with both 1.5 and 3T - subjective symptoms were evaluated at the beginning of MRI activity and after 2 months by using an ad hoc questionnaire. The questionnaire also included items on occupational stress. RESULTS: At the start of MRI activity, 81% of the subjects reported at least one of the investigated symptoms; after 2 months, 85% of the symptomatic operators reported the regression of one or more symptoms. In operators with high exposure (1.5 and 3 T scanners), the mean number of symptoms tended to be higher compared with those with lower exposure (1.5 T only), and the reduction after 2 months was significantly greater. In the whole group, occupational stress was significantly correlated with the total number of symptoms and to some of the symptoms more specifically. As stress did not differ between highly- and lowly- exposed, there is no reason to assume an influence on the observed differences in the prevalence and reduction of symptoms. CONCLUSIONS: Our data suggest that MRI operators may experience various symptoms at the beginning of activity, rapidly reversible in a few weeks. The trend over longer periods deserves further study. Occupational stress may play a role in symptoms. The duration of previous MRI work (particularly short-term) as well as work-related stress should be adequately addressed in future studies on subjective symptoms in operators.

Outdoor work and solar radiation exposure: Evaluation method for epidemiological studies.

BACKGROUND: The health risk related to an excessive exposure to solar radiation (SR) is well known. The Sun represents the main exposure source for all the frequency bands of optical radiation, that is the part of the electromagnetic spectrum ranging between 100 nm and 1 mm, including infrared (IR), ultraviolet (UV) and visible radiation. According to recent studies, outdoor workers have a relevant exposure to SR but few studies available in scientific literature have attempted to retrace a detailed history of individual exposure. MATERIAL AND METHODS: We propose a new method for the evaluation of SR cumulative exposure both during work and leisure time, integrating subjective and objective data. The former is collected by means of an interviewer administrated questionnaire. The latter is available through the Internet databases for many geographical regions and through individual exposure measurements. The data is integrated into a mathematical algorithm, in order to obtain an esteem of the individual total amount of SR the subjects have been exposed to during their lives. RESULTS: The questionnaire has been tested for 58 voluntary subjects. Environmental exposure data through online databases has been collected for 3 different places in Italy in 2012. Individual exposure by electronic UV dosimeter has been measured in 6 fishermen. A mathematical algorithm integrating subjective and objective data has been elaborated. CONCLUSIONS: The method proposed may be used in epidemiological studies to evaluate specific correlations with biological effects of SR and to weigh the role of the personal and environmental factors that may increase or reduce SR exposure. Med Pr 2016;67(5):577-587.

Upper limb musculoskeletal disorders in healthcare personnel.

The literature on upper limb musculoskeletal disorders (UL-MSD) in different groups of healthcare workers was reviewed: 65 relevant studies were collected. In dentists, the neck was the most frequently affected segment, with prevalences up to 73% and exceeding 50% in 7 out of 12 studies. In dental hygienists and in laboratory technicians, the hand/wrist had the highest prevalence in the majority of the studies. In nurses, the most seriously affected anatomic sites were the neck and shoulders. Physiotherapists had the lowest prevalence of UL-MSD. A high prevalence of upper limb disease, mainly carpal tunnel syndrome, was reported in dentists, dental hygienists, anesthesia nurses and endoscopists. The high prevalence of upper limb disorders/diseases reported in health personnel supports the hypothesis of a significant risk in these workers. However, the possible role of biomechanical overload, as much as that of stress or other personal factors, cannot be currently assessed. Practitioner Summary: Published studies support the hypothesis of a significant risk of upper limb musculoskeletal disorders in healthcare activities. The neck was the most frequently affected segment in dentists, the hand/wrist in dental hygienists and in laboratory technicians, and the neck and shoulders in nurses. Lower prevalence was reported in physiotherapists. A high prevalence of carpal tunnel syndrome was also observed in various healthcare activities.

Self-reported neck symptoms and use of personal computers, laptops and cell phones among Finns aged 18-65.

The purpose of this study was to investigate the possible relation between self-reported neck symptoms (aches, pain or numbness) and use of computers/cell phones. The study was carried out as a cross-sectional study by posting a questionnaire to 15,000 working-age persons, and 15.1% of all respondents (6121) reported that they very often experienced physical symptoms in the neck. The results showed that they also had many other symptoms very often, and 49% used a computer daily at work and 83.9% used cell phones. We compared physical/mental symptoms of persons with symptoms in the neck quite often or more, with others. We found significant differences in the physical/mental symptoms and use of cell phones and computers. The results suggest taking into account in the future that those persons' symptoms in the neck can be associated with use of cell phones or computers. PRACTITIONER SUMMARY: We investigated the possible relation between neck symptoms and use of computers/cell phones. We found that persons, who very often had symptoms in the neck, had also other symptoms very often (e.g. exhaustion at work). Their use of information and communication technology (e.g. computers) can associate with their symptoms.

Risk of cutaneous squamous cell carcinoma due to occupational exposure to solar ultraviolet radiation: Protocol for a systematic review and meta-analysis.

Solar ultraviolet radiation (UVR) is the most significant occupational carcinogenic exposure in terms of the number of workers exposed (i.e., outdoor workers). Consequently, solar UVR-induced skin cancers are among the most common forms of occupational malignancies that are potentially expected globally. This systematic review is registered in PROSPERO (CRD42021295221) and aims to assess the risk of cutaneous squamous cell carcinoma (cSCC) associated to occupational solar UVR exposure. Systematic searches will be performed in three electronic literature databases (PubMed/Medline, EMBASE, and Scopus). Further references will be retrieved by a manual search (e.g., in grey literature databases, internet search engines, and organizational websites). We will include cohort studies and case-control studies. Risk of Bias assessment will be conducted separately for case-control and cohort studies. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) will be used for the certainty of assessment. In case quantitative pooling is not feasible, a narrative synthesis of results will be performed.

Digitally measuring solar ultraviolet radiation in outdoor workers: A study protocol for establishing the use of electronic personal dosimeters in Portugal.

Introduction: The rising incidence of skin cancer over the years has made it a significant public and occupational health issue. However, skin cancer is highly preventable, mainly through reduced exposure to solar ultraviolet radiation (UVR), which can be achieved by a variety of individual and collective protective measures and interventions. The relative risk associated with different patterns of exposure to solar UVR differs for the subtypes of keratinocyte cancers (KC). Specifically, whether the exposure is intermittent or continuous, and occurs in an occupational or leisure/recreational setting. The main aim of the study using this protocol is to contribute to raising public and policy awareness on solar UVR-inflicted occupational skin cancers in Lisbon. This will be achieved by performing direct measurements of the solar UVR dose received by outdoor workers using a digital platform. Results will likely contribute to further understanding the risk estimates for keratinocyte cancer estimations in this population. Methods: A prospective observational study will be conducted in Lisbon, Portugal. Personal electronic dosimeters (GENESIS-UV system) integrated with a digital platform will be used to assess occupational solar UVR doses of gardeners, masons, and gravediggers of the municipality of Lisbon. Two hundred and ten outdoor workers will be selected to wear the dosimeter for 1 month each, between April and October during their daily working hours. A digital web-based platform that offers private access to information through dashboard visualization will provide information for the outdoor workers and facilitate communication with the participants. Discussion: The expected results of the overall proposal comprise the occupational solar UVR doses, expressed in standard erythemal dose (SEDs) per day of outdoor work for 7 months. Study data will provide outdoor workers with information on their personal solar UVR exposure during their working hours and an estimate of their risk of developing skin cancer. It is expected that the occupational solar UVR doses of the outdoor workers in Portugal will be above the threshold of 1 to 1.33 SED/day, due to the latitude of Lisbon and the nature of the occupations. The results prospectively should flow into the design of adequate prevention campaigns for skin cancer in outdoor workers.

Factors Associated with SARS-CoV-2 Infection Evaluated by Antibody Response in a Sample of Workers from the Emilia-Romagna Region, Northern Italy.

Factors associated with SARS-CoV-2 infection risk are still debated. This case-control study aims to investigate the possible relationship between SARS-CoV-2 infection, evaluated through antibody response, and the main sociodemographic, occupational, clinical-anamnestic, and biochemical factors in a population of Modena province (Northern Italy), mainly workers. Both workers who voluntarily joined the screening campaign proposed by companies and self-referred individuals who underwent serological testing were enrolled. Subjects with antibody positivity were recruited as cases (n = 166) and subjects tested negative (n = 239) as controls. A questionnaire on sociodemographic, occupational, and clinical data was administered through telephone interviews. Serum zinc/iron/copper/chromium/nickel, vitamins D/B12, folates, triglycerides, and LDL/HDL/total cholesterol were measured. Cases lived more often in urban areas (61.8% vs. 57%). Cases and controls did not differ significantly by working macrocategories, but the percentage of workers in the ceramic sector was higher among cases. Low adherence to preventive measures in the workplace was more frequent among seropositives. Folate concentration was significantly lower among cases. Therefore, adequate folate levels, living in rural areas, and good adherence to preventive strategies seem protective against infection. Workers in the ceramic sector seem to be at greater risk; specific factors involved are not defined, but preventive interventions are needed.

Incidence and Determinants of Symptomatic and Asymptomatic SARS-CoV-2 Breakthrough Infections After Booster Dose in a Large European Multicentric Cohort of Health Workers-ORCHESTRA Project.

BACKGROUND: SARS-CoV-2 breakthrough infections (BI) after vaccine booster dose are a relevant public health issue. METHODS: Multicentric longitudinal cohort study within the ORCHESTRA project, involving 63,516 health workers (HW) from 14 European settings. The study investigated the cumulative incidence of SARS-CoV-2 BI after booster dose and its correlation with age, sex, job title, previous infection, and time since third dose. RESULTS: 13,093 (20.6%) BI were observed. The cumulative incidence of BI was higher in women and in HW aged < 50 years, but nearly halved after 60 years. Nurses experienced the highest BI incidence, and administrative staff experienced the lowest. The BI incidence was higher in immunosuppressed HW (28.6%) vs others (24.9%). When controlling for gender, age, job title and infection before booster, heterologous vaccination reduced BI incidence with respect to the BNT162b2 mRNA vaccine [Odds Ratio (OR) 0.69, 95% CI 0.63-0.76]. Previous infection protected against asymptomatic infection [Relative Risk Ratio (RRR) of recent infection vs no infection 0.53, 95% CI 0.23-1.20] and even more against symptomatic infections [RRR 0.11, 95% CI 0.05-0.25]. Symptomatic infections increased from 70.5% in HW receiving the booster dose since < 64 days to 86.2% when time elapsed was > 130 days. CONCLUSIONS: The risk of BI after booster is significantly reduced by previous infection, heterologous vaccination, and older ages. Immunosuppression is relevant for increased BI incidence. Time elapsed from booster affects BI severity, confirming the public health usefulness of booster. Further research should focus on BI trend after 4th dose and its relationship with time variables across the epidemics.

White-collar workers' self-reported physical symptoms associated with using computers.

The aim of our work was to study the physical symptoms of upper- and lower-level white-collar workers using a questionnaire. The study was cross-sectional with a questionnaire posted to 15 000 working-age persons. The responses (6121) included 970 upper- and 1150 lower-level white-collar workers. In the upper- and lower-level white-collar worker groups, 45.7 and 56.0%, respectively, had experienced pain, numbness and aches in the neck either pretty often or more frequently. When comparing daily computer users and nonusers, there were significant differences in pain, numbness and aches in the neck or in the shoulders. In addition, age and gender influenced some physical symptoms. In the future, it is essential to take into account that working with computers can be especially associated with physical symptoms in the neck and in the shoulders when workers use computers daily.