Promoting patient-centred care in the management of allergic rhinitis in Asia-Pacific countries.

Background: Allergic rhinitis (AR) has a high burden of disease in the Asia-Pacific region (APAC). Although guidelines provide recommendations regarding the diagnosis and treatment of AR, it is increasingly being recognised that there are gaps in their implementation. Patient-centred care involves accounting for the specific needs and desires of patients as well as including the patient in the decision-making process, and this may provide a means to reduce these gaps and consequently the burden of AR. Methods: A group of 11 experts in immunology and otorhinolaryngology from APAC provided information regarding their practices and experiences in the management of AR through an online survey. The group then discussed the barriers and solutions for the implementation of patient-centred care across the patient journey in a face-to-face meeting. Results: Key barriers to the implementation of patient-centred care for AR in APAC included a lack of patient awareness of the condition and treatment options, low adherence to treatments, financial constraints for patients, and time constraints for physicians. The solutions proposed include improving the knowledge of the patients about their conditions, the use of shared decision-making, the consideration of patient characteristics when choosing treatments, and the use of outcome measures to aid the optimisation of patient care. We provide specific recommendations for clinical practice. Conclusion: A greater focus on patient-centred approaches has the potential to improve the management of AR in APAC. More emphasis should be placed on each patient's specific health needs and desired outcomes.

Antecedent and persistent symptoms in COVID-19 and other respiratory illnesses: insights from prospectively collected data in the BRACE trial.

BACKGROUND: Some individuals have a persistence of symptoms following both COVID-19 (post-acute COVID-19 syndrome; PACS) and other viral infections. This study used prospective data from an international trial to compare symptoms following COVID-19 and non-COVID-19 respiratory illnesses, identify factors associated with the risk of PACS, and explore symptom patterns before and after COVID-19 and non-COVID-19 respiratory illnesses. METHODS: Data from a multicentre randomised controlled trial (BRACE trial) involving healthcare workers across four countries were analysed. Symptom data were prospectively collected over 12 months, allowing detailed characterisation of symptom patterns. Participants with COVID-19 and non-COVID-19 respiratory illness episodes were compared, focussing on symptom severity, duration (including PACS using NICE and WHO definitions), and pre-existing symptoms. FINDINGS: Participants with COVID-19 had significantly more severe illness compared to those with non-COVID-19 respiratory illnesses (OR 7·4, 95%CI 5·6-9·7). Symptom duration meeting PACS definitions occurred in a higher proportion of COVID-19 cases than non-COVID-19 respiratory controls using both the NICE definition (2·5% vs 0·5%, OR 6·6, 95%CI 2·4-18·3) and the WHO definition (8·8% vs 3·7%, OR 2·5, 95%CI 1·4-4·3). When considering only participants with COVID-19, age (aOR 2·8, 95%CI 1·3-6·2), chronic respiratory disease (aOR 5·5, 95%CI 1·3-23·1), and pre-existing symptoms (aOR 3·0, 95%CI 1·4-6·3) were associated with an increased risk of developing PACS. Symptoms associated with PACS were also reported by participants in the months preceding their COVID-19 or non-COVID-19 respiratory illnesses (32% fatigue and muscle ache, 11% intermittent cough and shortness of breath). INTERPRETATION: Healthcare workers with COVID-19 experienced more severe and longer-lasting symptoms than those with non-COVID-19 respiratory illnesses, with a higher proportion meeting the WHO or NICE definitions of PACS. Age, chronic respiratory disease, and pre-existing symptoms increased the risk of developing PACS following COVID-19. FUNDING: Bill & Melinda Gates Foundation [INV-017302] and others (see Acknowledgements).

Comparing Skin and Serum Testing to Direct Challenge Outcomes in Children With ß-Lactam Allergies.

BACKGROUND: There is a scarcity of prospective studies investigating the relative roles of skin prick and intradermal testing, serum specific IgE, and extended oral challenges in diagnosing children with reported ß-lactam allergies. OBJECTIVE: To determine the sensitivity and specificity of skin testing and serum specific IgE in children with ß-lactam allergies, with immediate and nonimmediate historic reactions. METHODS: Four hundred children with parent-reported ß-lactam allergies were recruited into an open-label prospective study. Detailed allergy histories were collected. Those with medically observed and documented histories of anaphylaxis, requiring epinephrine, or severe cutaneous adverse reactions were excluded. In total, 380 children underwent all testing modalities and a direct provocation test. Each child was followed up for a minimum of 3 years. RESULTS: True allergy in children was uncommon; 8.3% reacted to the direct provocation challenge or the 5-day extended oral provocation challenge. Children reporting cephalosporin allergy or a reaction within 1 year were more likely to react to direct provocation testing. The sensitivity, specificity, and positive predictive value of skin testing were 12.5%, 98.8%, and 20.0% for direct challenge outcomes, 4.76%, 99.0%, and 25.0% for extended challenge outcomes, and 6.9%, 99.0%, and 40.0% for both challenges combined, respectively. Follow-up investigations revealed that 5.7% of children had a mild repeat reaction and 2.7% continued to avoid the culprit despite successful delabeling. The relabeling rate for children readmitted to hospital was 15%, with the relabeing being unfounded. CONCLUSIONS: Genuine ß-lactam allergies were rare, with over 90% of children effectively delabeled. Skin and serum specific IgE testing did not aid the diagnosis of ß-lactam antibiotic allergy in children, regardless of medical history. Extended oral challenges proved valuable in confirming allergies and boosted parental confidence.

BCG vaccination of healthcare workers for protection against COVID-19: 12-month outcomes from an international randomised controlled trial.

OBJECTIVES: Bacille Calmette-Guérin (BCG) vaccine has immunomodulatory effects that may provide protection against unrelated infectious diseases. We aimed to determine whether BCG vaccination protects adults against COVID-19. DESIGN: Phase III double-blind randomised controlled trial. SETTING: Healthcare centres in Australia, Brazil, the Netherlands, Spain, and the United Kingdom during the COVID-19 pandemic. PARTICIPANTS: 3988 healthcare workers with no prior COVID-19 and no contraindication to BCG. INTERVENTION: Randomised 1:1 using a web-based procedure to receive a single 0.1 mL intradermal dose of BCG-Denmark (BCG group, n = 1999) or saline (placebo group, n = 1989). MAIN OUTCOME MEASURES: Difference in incidence of (i) symptomatic and (ii) severe COVID-19 during the 12 months following randomisation in the modified intention to treat (mITT) population (confirmed SARS-CoV-2 naïve at inclusion). RESULTS: Of the 3988 participants randomised, 3386 had a negative baseline SARS-CoV-2 test and were included in the mITT population. The 12-month adjusted estimated risk of symptomatic COVID-19 was higher in the BCG group (22.6%; 95% confidence interval [CI] 20.6 to 24.5%) compared with the placebo group (19.6%; 95% CI 17.6 to 21.5%); adjusted difference +3.0% points (95% CI 0.2 to 5.8%; p = 0.04). The 12-month adjusted estimated risk of severe COVID-19 (mainly comprising those reporting being unable to work for ≥3 consecutive days) was 11.0% in the BCG group (95% CI 9.5 to 12.4%) compared with 9.6% in the placebo group (95% CI 8.3 to 11.1%); adjusted difference +1.3% points (95% CI -0.7 to 3.3%, p = 0.2). Breakthrough COVID-19 (post COVID-19 vaccination) and asymptomatic SARS-CoV-2 infections were similar in the two groups. There were 18 hospitalisations due to COVID-19 (11 in BCG group, 7 in placebo group; adjusted hazard ratio 1.56, 95% CI 0.60 to 4.02, p = 0.4) and two deaths due to COVID-19, both in the placebo group. CONCLUSIONS: Compared to placebo, vaccination with BCG-Denmark increased the risk of symptomatic COVID-19 over 12 months among healthcare workers and did not decrease the risk of severe COVID-19 or post-vaccination breakthrough COVID-19. TRIAL REGISTRATION: ClinicalTrials.gov NCT04327206.

Impact of a drug allergy education course for non-specialists: Findings from ADAPT-A randomized crossover trial.

BACKGROUND: The consequences of drug allergy remain a global health concern. Drug allergy is often a neglected topic and many non-specialists lack sufficient knowledge or confidence in evaluating or managing this common condition. Evidence-based interventions to better equip non-specialists to tackle drug allergy are needed. The aim of the study is to evaluate the effectiveness of an intensive educational course on drug allergy knowledge and practice of non-specialists. METHODS: A randomized crossover trial (NCT06399601) was conducted among practicing physicians and nurses participating in an intensive drug allergy course-Advances in Drug Allergy & Penicillin Testing (ADAPT). Participants' baseline knowledge and self-reported practices were assessed with standardized questionnaires (scored from 0 to 100, with "satisfactory" defined as ≥60/100). Participants were randomized into two cohorts and attended ADAPT at different time points. Serial responses before and after the course were compared within and between cohorts. RESULTS: Seventy participants (25 physicians, 45 nurses) randomized into two groups completed the course. Baseline drug allergy knowledge (58.0 ± 19.9) and self-reported practice (36.9 ± 24.3) were unsatisfactory among non-specialists, with significantly lower scores from nurses than physicians in both domains (knowledge: 49.0 ± 17.4 vs. 74.0 ± 12.7; practice: 32.1 ± 21.3 vs. 53.3 ± 23.1; all p < 0.001). Following completion of ADAPT, participants demonstrated significant improvements in knowledge (58.0 ± 19.9 vs. 77.7 ± 15.9, p < 0.001) and self-reported practice (36.9 ± 24.3 vs. 71.0 ± 20.2, p < 0.001). All participants (100%) and 99% of participants agreed that the course improved their clinical knowledge and practice, respectively. CONCLUSIONS: ADAPT, an intensive drug allergy educational course was effective in improving drug allergy knowledge and practice for non-specialists. Further longitudinal studies are required to evaluate long-term impact.

Omalizumab for management of hypersensitivity reactions to anticancer drugs.

Hypersensitivity reactions to anticancer drugs include treatment-limiting toxicity. Standard drug desensitisation offers temporary tolerance and hence requires repetition. We used omalizumab, an anti-immunoglobulin E antibody, to overcome immediate and delayed hypersensitivity reactions to various anticancer drugs. Seven of the eight patients in the current study successfully resumed the desired anticancer drug regimen without standard desensitisation. No safety issues from omalizumab were observed.

Bacille Calmette-Guérin vaccination to prevent febrile and respiratory illness in adults (BRACE): secondary outcomes of a randomised controlled phase 3 trial.

Background: Bacille Calmette-Guérin (BCG) vaccination has off-target (non-specific) effects that are associated with protection against unrelated infections and decreased all-cause mortality in infants. We aimed to determine whether BCG vaccination prevents febrile and respiratory infections in adults. Methods: This randomised controlled phase 3 trial was done in 36 healthcare centres in Australia, Brazil, the Netherlands, Spain, and the United Kingdom. Healthcare workers were randomised to receive BCG-Denmark (single 0.1 ml intradermal injection) or no BCG in a 1:1 ratio using a web-based procedure, stratified by stage, site, age, and presence of co-morbidity. The difference in occurrence of febrile or respiratory illness were measured over 12 months (prespecified secondary outcome) using the intention-to-treat (ITT) population. This trial is registered with ClinicalTrials.gov, NCT04327206. Findings: Between March 30, 2020, and April 1, 2021, 6828 healthcare workers were randomised to BCG-Denmark (n = 3417) or control (n = 3411; no intervention or placebo) groups. The 12-month adjusted estimated risk of ≥1 episode of febrile or respiratory illness was 66.8% in the BCG group (95% CI 65.3%-68.2%), compared with 63.4% in the control group (95% CI 61.8%-65.0%), a difference of +3.4 percentage points (95% CI +1.3% to +5.5%; p 0.002). The adjusted estimated risk of a severe episode (defined as being incapacitated for ≥3 consecutive days or hospitalised) was 19.4% in the BCG group (95% CI 18.0%-20.7%), compared with 18.8% in the control group (95% CI 17.4%-20.2%) a difference of +0.6 percentage points (95% CI -1.3% to +2.5%; p 0.6). Both groups had a similar number of episodes of illness, pneumonia, and hospitalisation. There were three deaths, all in the control group. There were no safety concerns following BCG vaccination. Interpretation: In contrast to the beneficial off-target effects reported following neonatal BCG in infants, a small increased risk of symptomatic febrile or respiratory illness was observed in the 12 months following BCG vaccination in adults. There was no evidence of a difference in the risk of severe disease. Funding: Bill & Melinda Gates Foundation, Minderoo Foundation, Sarah and Lachlan Murdoch, the Royal Children's Hospital Foundation, Health Services Union NSW, the Peter Sowerby Foundation, SA Health, the Insurance Advisernet Foundation, the NAB Foundation, the Calvert-Jones Foundation, the Modara Pines Charitable Foundation, the UHG Foundation Pty Ltd, Epworth Healthcare, the National Health and Medical Research Council, the Swiss National Science Foundation and individual donors.

Perspectives and gaps in the management of food allergy and anaphylaxis in the Asia-Pacific Region.

Background: Food allergy (FA), which is a condition that has no effective cure and can result in severe life-threatening allergic reactions, remains a global public health concern; however, little is known about how FAs are currently managed in the Asia-Pacific region. Objective: The main objective of this survey was to evaluate the epidemiology of FA, as well as the availability of resources and practices for management of FA and anaphylaxis by health care providers across Asia. Methods: From June 2022 to September 2022, a questionnaire-based survey comprising 66 questions was electronically sent to member societies of the Asia Pacific Association of Allergy Asthma and Clinical Immunology by using Survey Monkey. Results: A total of 20 responses were received from 15 member countries and territories. Compared with the pediatric data, there was a lack of prevalence data for FA in adults. Except for Australia and Japan, most regions had between 0.1 and 0.5 allergists per 100,000 population and some had fewer than 0.1 allergists per 100,000 population. The perceived rate of FA in regions with a short supply of allergists was high. Although specific IgE tests and oral food challenges were available in all regions, the median wait time for oral food challenges at government facilities was 37 days (interquartile range = 10.5-60 days). Seven regions still relied on prescriptions of ampules and syringes of injectable adrenaline, and adrenaline autoinjectors were not accessible in 4 regions. Oral immunotherapy as FA treatment was available in half of the surveyed countries and territories. Conclusions: Our study offers a cross-sectional evaluation of the management practices for FA in each Asia Pacific Association of Allergy Asthma and Clinical Immunology member country or territory. Urgent actions are required to enhance allergy services, improve the accessibility and affordability of adrenaline autoinjectors, and conduct robust epidemiologic studies.

Assessing the contribution of plastic-associated obesogenic compounds to cardiometabolic diseases.

PURPOSE OF REVIEW: To present recent evidence that strengthens the concept that exogenous pollutants contribute to adipose dysfunction and increased rates of disease and to highlight the ineffective regulation of this risk as industry switches to related but similarly toxic variants. RECENT FINDINGS: Substitutes for common phthalates and the highly regulated bisphenol A (BPA) show similar deleterious effects on adipocytes. The well tolerated limit for BPA exposure has been reduced in Europe to below the level detected in recent population studies. Additionally, the role for BPA-induced inflammation mediated by interleukin 17a has been described in animal and human studies. SUMMARY: Despite experimental and associative evidence that supports plastics and plastic associated chemicals deleteriously influencing adipose homeostatasis and contributing to metabolic diseases, structurally related alternate chemicals are being substituted by manufacturers to circumvent trailing regulatory actions.

APAAACI clinical pathway on direct provocation testing for penicillin allergy delabeling.

Background: Allergy to penicillin is commonly reported in many countries and is an overwhelming global public health concern. Penicillin allergy labels can lead to the use of less effective antibiotics and can be associated with antimicrobial resistance. Appropriate assessment of suspected penicillin allergy (often including skin testing, followed by drug provocation testing [DPT] performed by allergists) can prevent the unnecessary restriction of penicillin or delabelling. Many countries in the Asia Pacific (AP) have very limited access to allergy services, and there are significant disparities in the methods of evaluating penicillin allergy. Therefore, a clinical pathway for the management of penicillin allergy is essential. Objectives: To develop a risk-stratified clinical pathway for delabeling penicillin allergy, taking into account the distinct epidemiology, patient/sensitization profiles, and disparities of allergy services or facilities within the AP. Methods: A risk-stratified penicillin allergy delabeling clinical pathway was formulated by the Drug Allergy Committee of the Asia Pacific Association of Allergy, Asthma and Clinical Immunology. and members of the Penicillin Allergy Disparities survey in AP each representing one country/region of the AP. The clinical pathway was tested based on a database of anonymized patients who were sequentially referred for and completed penicillin allergy evaluation in Hong Kong. Results: The clinical pathway was piloted employing a "hub-and-spoke" approach to foster multidisciplinary collaboration between allergists and nonallergists. A simulation run of the algorithm on a retrospective Hong Kong cohort of 439 patients was performed. Overall, 367 (84%) of patients were suitable for direct DPT and reduced the need for skin testing or specialist's care for 357 (97%) skin test-negative individuals. Out of the skin test-negative patients, 345 (94%) patients had a negative DPT. Conclusions: This risk-stratification strategy for direct oral DPT can reduce the need for unnecessary skin testing in patients with low-risk penicillin allergy histories. The hub and spoke model of care may be considered for further piloting and validation in other AP populations that lack adequately trained allergists.

Bacillus Calmette-Guérin vaccination for protection against recurrent herpes labialis: a nested randomised controlled trial.

Background: Recurrences of herpes simplex virus (HSV) in the orofacial region (herpes labialis or cold sores) impact quality-of-life. We aimed to study whether the bacille Calmette-Guérin (BCG) vaccine can attenuate cold sore recurrences through off-target immunomodulatory effects. Methods: In this nested randomised controlled trial within the multicentre, phase 3 BRACE trial, 6828 healthcare workers were randomised in 36 sites in Australia, the Netherlands, Spain, the United Kingdom and Brazil, to receive BCG-Denmark or no BCG (1:1 ratio using a web-based procedure) and followed for 12 months with 3-monthly questionnaires. Exclusion criteria included contraindication to BCG vaccine or previous vaccination with BCG within the past year, any other live-attenuated vaccine within the last month, or any COVID-specific vaccine. The intervention group received one intradermal dose of 0.1 mL of BCG-Denmark corresponding to 2-8 x 105 colony forming units of Mycobacterium bovis, Danish strain 1331. The primary outcome was the difference in restricted mean survival time (i.e., time to first cold-sore recurrence), in participants with frequent recurrent herpes labialis (≥4 recurrences/year), analysed by intention-to-treat. Secondary outcomes addressed additional questions, including analyses in other sub-populations. Adverse events were monitored closely during the first 3 months and were reported in all participants who received one dose of study drug according to intervention received. The BRACE trial is registered with ClinicalTrials.gov, NCT04327206. Findings: Between March 30, 2020 and February 18, 2021, 84 individuals with frequent recurrent cold sores were randomly assigned to BCG (n = 38) or control (n = 46). The average time to first cold-sore recurrence was 1.55 months longer in the BCG group (95% CI 0.27-2.82, p = 0.02) than the control group (hazard ratio 0.54, 95% CI 0.32-0.91; intention-to-treat). The beneficial effect of BCG was greater in the as-treated population (difference 1.91 months, 95% CI 0.69-3.12, p = 0.003; hazard ratio 0.45, 95% CI 0.26-0.76). In prespecified subgroup analyses, only sex modified the treatment effect (interaction p = 0.007), with benefit restricted to males. Over 12 months, a greater proportion of participants in the BCG group compared with the control group reported a decrease in duration (61% vs 21%), severity (74% vs 21%), frequency (55% vs 21%), and impact on quality of life (42% vs 15%) of cold sore recurrences. In participants who had ever had a cold sore, there was also a decrease in self-reported burden of recurrences in the BCG group. In participants who had never had a cold sore, there was an increased risk of a first episode in the BCG group (risk difference 1.4%; 95% CI 0.3-2.6%, p = 0.02). There were no safety concerns. Interpretation: BCG-Denmark vaccination had a beneficial effect on herpes labialis, particularly in males with frequent recurrences, but may increase the risk of a first cold sore. Funding: Bill & Melinda Gates Foundation, the Minderoo Foundation, Sarah and Lachlan Murdoch, the Royal Children's Hospital Foundation, Health Services Union NSW, the Peter Sowerby Foundation, SA Health, the Insurance Advisernet Foundation, the NAB Foundation, the Calvert-Jones Foundation, the Modara Pines Charitable Foundation, the UHG Foundation Pty Ltd, Epworth Healthcare, and individual donors.

Severe allergic systemic reaction to personal protective equipment during the COVID-19 pandemic.

Our case describes a hospital worker who suffered a severe reaction to personal protective equipment (PPE) during the COVID-19 pandemic. After researching the excipient list of her PPE and completing a literature review, we postulated that isocyanates used in the production of the polyurethane band of the N95 mask was the cause for her reaction. In the absence of standardised testing, we tested this hypothesis by replicating her reaction to PPE by using a commercially available isocyanate patch, identifying diphenylmethane-4, 4-diisocyanate as the culprit agent.We recommended caution in the use of polyurethane containing N95 masks- for people reporting allergic reaction- and testing for sensitivity for polyurethane. The patient was able to tolerate non-polyurethane containing standard surgical masks, providing an option for PPE in some clinical circumstances. Since avoiding N95 masks, she has not had any further reactions.

Erratum: Factors influencing scar formation following Bacille Calmette-Guérin (BCG) vaccination.

[This corrects the article DOI: 10.1016/j.heliyon.2023.e15241.].

The Burden of Self-Reported Antibiotic Allergies in Health Care and How to Address It: A Systematic Review of the Evidence.

BACKGROUND: Antibiotics are the first-line treatment for bacterial infections; however, overuse and inappropriate prescribing have made antibiotics less effective with increased antimicrobial resistance. Unconfirmed reported antibiotic allergy labels create a significant barrier to optimal antimicrobial stewardship in health care, with clinical and economic implications. OBJECTIVE: A systematic review was conducted to summarize the impact of patient-reported antibiotic allergy on clinical outcomes and various strategies that have been employed to effectively assess and remove these allergy labels, improving patient care. METHODS: The review was undertaken using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A critical appraisal was conducted on all studies and a narrative synthesis was performed to identify themes. RESULTS: Four themes emerged: the prevalence of antibiotic allergy, impact of antibiotic allergy on antimicrobial prescribing, impact of antibiotic allergy on clinical outcomes, and delabeling strategies to improve clinical outcomes. Of the 32 studies, including 1,089,675 participants, the prevalence of reported antibiotic allergy was between 5% and 35%. Patients with a reported antibiotic allergy had poorer concordance with prescribing guidelines in 30% to 60% of cases, with a higher use of alternatives such as quinolone, tetracycline, macrolide, lincosamide, and carbapenem and lower use of beta-lactam antibiotics. Antibiotic allergy delabeling was identified as an intervention and recommendation to advance the state of the science. CONCLUSIONS: There is substantial evidence within the literature that antibiotic allergy labels significantly impact patient clinical outcomes and a consensus that systematic assessment of reported antibiotic allergies, commonly referred to as delabeling, improves the clinical management of patients.

Factors influencing scar formation following Bacille Calmette-Guérin (BCG) vaccination.

The prevalence of scar formation following Bacille Calmette-Guérin (BCG) vaccination varies globally. The beneficial off-target effects of BCG are proposed to be stronger amongst children who develop a BCG scar. Within an international randomised trial ('BCG vaccination to reduce the impact of coronavirus disease 2019 (COVID-19) in healthcare workers'; BRACE Trial), this nested prospective cohort study assessed the prevalence of and factors influencing scar formation, as well as participant perception of BCG scarring 12 months following vaccination . Amongst 3071 BCG-recipients, 2341 (76%) developed a BCG scar. Scar prevalence was lowest in Spain and highest in UK. Absence of post-injection wheal (OR 0.4, 95%CI 0.2-0.9), BCG revaccination (OR 1.7, 95%CI 1.3-2.0), female sex (OR 2.0, 95%CI 1.7-2.4), older age (OR 0.4, 95%CI 0.4-0.5) and study country (Brazil OR 1.6, 95%CI 1.3-2.0) influenced BCG scar prevalence. Of the 2341 participants with a BCG scar, 1806 (77%) did not mind having the scar. Participants more likely to not mind were those in Brazil, males and those with a prior BCG vaccination history. The majority (96%) did not regret having the vaccine. Both vaccination-related (amenable to optimisation) and individual-related factors affected BCG scar prevalence 12 months following BCG vaccination of adults, with implications for maximising the effectiveness of BCG vaccination.

Randomized Trial of BCG Vaccine to Protect against Covid-19 in Health Care Workers.

BACKGROUND: The bacille Calmette-Guérin (BCG) vaccine has immunomodulatory "off-target" effects that have been hypothesized to protect against coronavirus disease 2019 (Covid-19). METHODS: In this international, double-blind, placebo-controlled trial, we randomly assigned health care workers to receive the BCG-Denmark vaccine or saline placebo and followed them for 12 months. Symptomatic Covid-19 and severe Covid-19, the primary outcomes, were assessed at 6 months; the primary analyses involved the modified intention-to-treat population, which was restricted to participants with a negative test for severe acute respiratory syndrome coronavirus 2 at baseline. RESULTS: A total of 3988 participants underwent randomization; recruitment ceased before the planned sample size was reached owing to the availability of Covid-19 vaccines. The modified intention-to-treat population included 84.9% of the participants who underwent randomization: 1703 in the BCG group and 1683 in the placebo group. The estimated risk of symptomatic Covid-19 by 6 months was 14.7% in the BCG group and 12.3% in the placebo group (risk difference, 2.4 percentage points; 95% confidence interval [CI], -0.7 to 5.5; P = 0.13). The risk of severe Covid-19 by 6 months was 7.6% in the BCG group and 6.5% in the placebo group (risk difference, 1.1 percentage points; 95% CI, -1.2 to 3.5; P = 0.34); the majority of participants who met the trial definition of severe Covid-19 were not hospitalized but were unable to work for at least 3 consecutive days. In supplementary and sensitivity analyses that used less conservative censoring rules, the risk differences were similar but the confidence intervals were narrower. There were five hospitalizations due to Covid-19 in each group (including one death in the placebo group). The hazard ratio for any Covid-19 episode in the BCG group as compared with the placebo group was 1.23 (95% CI, 0.96 to 1.59). No safety concerns were identified. CONCLUSIONS: Vaccination with BCG-Denmark did not result in a lower risk of Covid-19 among health care workers than placebo. (Funded by the Bill and Melinda Gates Foundation and others; BRACE ClinicalTrials.gov number, NCT04327206.).

Subset-specific Retention of Donor Myeloid Cells After Major Histocompatibility Complex-matched and Mismatched Liver Transplantation.

BACKGROUND: During solid organ transplantation, donor leukocytes, including myeloid cells, are transferred within the organ to the recipient. Both tolerogenic and alloreactive roles have been attributed to donor myeloid cells; however, their subset-specific retention posttransplantation has not been investigated in detail. METHODS: Major histocompatibility complex (MHC)-matched and mismatched liver transplants were performed in mice, and the fate of donor and recipient myeloid cells was assessed. RESULTS: Following MHC-matched transplantation, a proportion of donor myeloid cells was retained in the graft, whereas others egressed and persisted in the blood, spleen, and bone marrow but not the lymph nodes. In contrast, after MHC-mismatched transplantation, all donor myeloid cells, except Kupffer cells, were depleted. This depletion was caused by recipient T and B cells because all donor myeloid subsets were retained in MHC-mismatched grafts when recipients lacked T and B cells. Recipient myeloid cells rapidly infiltrated MHC-matched and, to a greater extent, MHC-mismatched liver grafts. MHC-mismatched grafts underwent a transient rejection episode on day 7, coinciding with a transition in macrophages to a regulatory phenotype, after which rejection resolved. CONCLUSIONS: Phenotypic and kinetic differences in the myeloid cell responses between MHC-matched and mismatched grafts were identified. A detailed understanding of the dynamics of immune responses to transplantation is critical to improving graft outcomes.