Duration of SARS-CoV-2 shedding and infectivity in the working age population: a systematic review and meta-analysis

COVID-19 Marked a Change in the Scope of Occupational Medicine from Occupational to Work-Related Diseases and Total Worker Health®

The COVID-19 pandemic challenged occupational medicine, while its focus had already shifted from occupational diseases to work-related illnesses. Such a broader scope allowed the inclusion of transmissible diseases among the causes for concern in working settings. COVID-19 has had a profound impact globally, resulting in millions of infections, often lethal. From its appearance, COVID-19 was found to affect specific groups of workers at higher risk of contracting the virus due to their occupation or workplace conditions, which accounts for its consideration as a potential work-related disease. This overview examines various aspects of COVID-19 based on articles published in our journal. Specifically, the epidemiology of COVID-19 is discussed, including mortality rates and groups at higher risk. The diagnosis, measures to prevent contagion, vaccination efforts, long-term effects, and psychosocial factors are also summarized. The emerging picture is that COVID-19 has been a trigger accelerating the change of paradigm of occupational medicine, which is more and more concerned with prevention. Occupational Health contributes to health promotion and Total Worker Health®.

Learning from the Experience of the COVID-19 Pandemic: A New Paradigm for Occupational Biohazard Assessment and Management

The COVID-19 pandemic has affected workplaces in many different aspects. In this scenario, Occupational Physicians played a crucial role in assessing and managing the risk of SARS-CoV-2 infection and associated diseases to guarantee workers' health and the safety of workplaces. However, the pandemic experience has drawn attention to several critical issues in overall biohazard prevention and management strategies, originating from important knowledge gaps in our scientific understanding. An extensive analysis of the relevant hurdles that have emerged in our medical field can bring valuable lessons for the post pandemic future, not only in preparation for possible new pathogens with pandemic potential but also with principles and concepts applicable to managing all biological agents. In particular, a paradigm shift is needed to properly approach occupational diseases caused by infective agents, accurately define the "case", assess exposure and possible causal relationship with work appropriately, and effectively manage the specific risk through implementing appropriate preventive and protective measures. In this framework, the Occupational Physician should expand his contribution based on his unique expertise and specific competencies, confirming his role as the go-to consultant in all occupational health matters, but also in a multidisciplinary approach, considering different scientific expertise and evidence.

The immunogenicity of the ChAdOx1 nCoV-19 vaccination in participants with underlying comorbidity diseases: A prospective cohort study

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) increases mortality rates in older adults and those with comorbidities. Individuals with certain comorbidities may have a poor immune response and require early booster vaccines. We aimed to assess the immune response after two doses of ChAdOx1 nCoV-19 vaccine, at 84-day intervals, in participants with the following comorbidities; diabetes mellitus; obesity; cardiovascular disease; chronic kidney disease; rheumatological disease; cirrhosis; hematological disease; hematological malignancy; or solid malignancy. The study was conducted at Chulabhorn Hospital in Thailand, with healthy healthcare workers serving as the control group. Of the 769 participants, 352 were in the healthy cohort and 417 were in the comorbidity cohort, all received at least one dose of vaccine. Anti-RBD total antibody levels were evaluated on Day 0, Day 84, and Day 112. The results at Day 112 (4 weeks after the second dose) showed that individuals with comorbidities had a poor immune response compared to healthy individuals, especially those with hematological malignancy and solid malignancy. The geometric mean concentration (GMC) of anti-RBD antibody in the comorbidity cohort was significantly lower than that in the healthy cohort: 433.66 BAU/ml (95% CI 334.62-562.01) versus 1096.14 BAU/ml (95% CI 1010.26-1189.33), respectively. The geometric mean ratio (GMR) between the two cohorts was 0.40 (95% CI 0.30-0.52, p < .001). This study concluded that individuals with comorbidities, particularly hematological and solid malignancies, had poor immune responses and may require an early booster vaccine to prevent infection and death.

The effect of variation of individual infectiousness on SARS-CoV-2 transmission in households

Quantifying variation of individual infectiousness is critical to inform disease control. Previous studies reported substantial heterogeneity in transmission of many infectious diseases including SARS-CoV-2. However, those results are difficult to interpret since the number of contacts is rarely considered in such approaches. Here, we analyze data from 17 SARS-CoV-2 household transmission studies conducted in periods dominated by ancestral strains, in which the number of contacts was known. By fitting individual-based household transmission models to these data, accounting for number of contacts and baseline transmission probabilities, the pooled estimate suggests that the 20% most infectious cases have 3.1-fold (95% confidence interval: 2.2- to 4.2-fold) higher infectiousness than average cases, which is consistent with the observed heterogeneity in viral shedding. Household data can inform the estimation of transmission heterogeneity, which is important for epidemic management.

Effect of COVID-19 vaccines for the treatment of people with post-COVID-19 condition: a rapid review

Background: Vaccination for coronavirus disease 2019 (COVID-19) has demonstrated reduced risk of hospitalisation and death against more recent variants of COVID-19. Some studies suggested improvements in patients with post-COVID-19 condition (PCC) following vaccination. We systematically explored available evidence on the effect of COVID-19 vaccines for the treatment of people with PCC. Methods: We conducted a rapid review of the literature following systematic approaches. We searched Medline (OVID), EMBASE (Elsevier), ClinicalTrials.gov, and the International Clinical Trials Registry Platform (ICTRP) for randomised trials, non-randomised trials, controlled before-after studies, and interrupted time-series studies of the effect of COVID-19 vaccines for treating people with PCC. Two independent review authors screened citations. Two review authors  extracted data independently. We had planned to assess the risk of bias and use the GRADE approach (Grading of Recommendations, Assessment, Development, and Evaluation) to assess the certainty of evidence if there were completed studies. Results: We identified two ongoing randomised controlled trials. Both trials examine the effectiveness of therapeutic vaccines on PCC. The anticipated completion date of the CIMAvax-EGFA trial is January 2023, and the completion date of the COVID-19 mRNA vaccine trial is not stated. Conclusions: There is currently an absence of high‐quality evidence evaluating the effectiveness of COVID-19 vaccines for treating people with post-COVID-19 condition. The absence of published studies and only two ongoing trials highlight the need for additional studies on the effectiveness of vaccines for PCC. We recommend that researchers consider PCC as per the definition provided by the World Health Organization and use the available core outcome set for PCC in deciding which outcomes to measure and report in the trials. PROPSERO registration: CRD42022330821 (20/06/2022)