Prospective monitoring of adverse events following vaccination with Modified vaccinia Ankara - Bavarian Nordic (MVA-BN) administered to a Canadian population at risk of Mpox: A Canadian Immunization Research Network study

MVA-BN is an orthopoxvirus vaccine that provides protection against both smallpox and mpox. In June 2022, Canada launched a publicly-funded vaccination campaign to offer MVA-BN to at-risk populations including men who have sex with men (MSM) and sex workers. The safety of MVA-BN has not been assessed in this context. To address this, the Canadian National Vaccine Safety Network (CANVAS) conducted prospective safety surveillance during public health vaccination campaigns in Toronto, Ontario and in Vancouver, British Columbia. Vaccinated participants received a survey 7 and 30 days after each MVA-BN dose to elicit adverse health events. Unvaccinated individuals from a concurrent vaccine safety project evaluating COVID-19 vaccine safety were used as controls. Vaccinated and unvaccinated participants that reported a medically attended visit on their 7-day survey were interviewed. Vaccinated participants and unvaccinated controls were matched 1:1 based on age group, gender, sex and provincial study site. Overall, 1,173 vaccinated participants completed a 7-day survey, of whom 75 % (n = 878) also completed a 30-day survey. Mild to moderate injection site pain was reported by 60 % of vaccinated participants. Among vaccinated participants 8.4 % were HIV positive and when compared to HIV negative vaccinated individuals, local injection sites were less frequent in those with HIV (48 % vs 61 %, p = 0.021), but health events preventing work/school or requiring medical assessment were more frequent (7.1 % vs 3.1 %, p = 0.040). Health events interfering with work/school, or requiring medical assessment were less common in the vaccinated group than controls (3.3 % vs. 7.1 %, p < 0.010). No participants were hospitalized within 7 or 30 days of vaccination. No cases of severe neurological disease, skin disease, or myocarditis were identified. Our results demonstrate that the MVA-BN vaccine appears safe when used for mpox prevention, with a low frequency of severe adverse events and no hospitalizations observed.

Sources of viral respiratory infections in Canadian acute care hospital healthcare personnel

BACKGROUND

Viral respiratory illnesses are common causes of outbreaks and can be fatal to some patients.

AIM

To investigate the association between laboratory-confirmed viral respiratory infections and potential sources of exposure during the previous 7 days.

METHODS

In this nested case-control analysis, healthcare personnel from nine Canadian hospitals who developed acute respiratory illnesses during the winters of 2010/11-2013/14 submitted swabs that were tested for viral pathogens. Associated illness diaries and the weekly diaries of non-ill participants provided information on contact with people displaying symptoms of acute respiratory illness in the previous week. Conditional logistic regression assessed the association between cases, who were matched by study week and site with controls with no respiratory symptoms.

FINDINGS

There were 814 laboratory-confirmed viral respiratory illnesses. The adjusted odds ratio (aOR) of a viral illness was higher for healthcare personnel reporting exposures to ill household members [7.0, 95% confidence interval (CI) 5.4-9.1], co-workers (3.4, 95% CI 2.4-4.7) or other social contacts (5.1, 95% CI 3.6-7.1). Exposures to patients with respiratory illness were not associated with infection (aOR 0.9, 95% CI 0.7-1.2); however, healthcare personnel with direct patient contact did have higher odds (aOR 1.3, 95% CI 1.1-1.6). The aORs for exposure and for direct patient contact were similar for illnesses caused by influenza.

CONCLUSION

Community and co-worker contacts are important sources of viral respiratory illness in healthcare personnel, while exposure to patients with recognized respiratory infections is not associated. The comparatively low risk associated with direct patient contact may reflect transmission related to asymptomatic patients or unrecognized infections.

Microscopic Characterization of Membrane Transporter Function by In Silico Modeling and Simulation

Membrane transporters mediate one of the most fundamental processes in biology. They are the main gatekeepers controlling active traffic of materials in a highly selective and regulated manner between different cellular compartments demarcated by biological membranes. At the heart of the mechanism of membrane transporters lie protein conformational changes of diverse forms and magnitudes, which closely mediate critical aspects of the transport process, most importantly the coordinated motions of remotely located gating elements and their tight coupling to chemical processes such as binding, unbinding and translocation of transported substrate and cotransported ions, ATP binding and hydrolysis, and other molecular events fueling uphill transport of the cargo. An increasing number of functional studies have established the active participation of lipids and other components of biological membranes in the function of transporters and other membrane proteins, often acting as major signaling and regulating elements. Understanding the mechanistic details of these molecular processes require methods that offer high spatial and temporal resolutions. Computational modeling and simulations technologies empowered by advanced sampling and free energy calculations have reached a sufficiently mature state to become an indispensable component of mechanistic studies of membrane transporters in their natural environment of the membrane. In this article, we provide an overview of a number of major computational protocols and techniques commonly used in membrane transporter modeling and simulation studies. The article also includes practical hints on effective use of these methods, critical perspectives on their strengths and weak points, and examples of their successful applications to membrane transporters, selected from the research performed in our own laboratory.

Antimicrobial surfaces to prevent healthcare-associated infections: a systematic review

Contamination of the healthcare environment with pathogenic organisms contributes to the burden of healthcare-associated infection (HCAI). Antimicrobial surfaces are designed to reduce microbial contamination of healthcare surfaces. We aimed to determine whether antimicrobial surfaces prevent HCAI, transmission of antibiotic-resistant organisms (AROs), or microbial contamination, we conducted a systematic review of the use of antimicrobial surfaces in patient rooms. Outcomes included HCAI, ARO, and quantitative microbial contamination. Relevant databases were searched. Abstract review, full text review, and data abstraction were performed in duplicate. Risk of bias was assessed using the Cochrane Effective Practice and Organization Care (EPOC) Group risk of bias assessment tool and the strength of evidence determined using Grading of Recommendations Assessment, Development and Evaluation (GRADE). Eleven studies assessed the effect of copper (N = 7), silver (N = 1), metal-alloy (N = 1), or organosilane-treated surfaces (N = 2) on microbial contamination. Copper surfaces demonstrated a median (range) reduction of microbial contamination of <1 log10 (<1 to 2 log10). Two studies addressed HCAI/ARO incidence. An RCT of copper surfaces in an ICU demonstrated 58% reduction in HCAI (P = 0.013) and 64% reduction in ARO transmission (P = 0.063) but was considered low-quality evidence due to improper randomization and incomplete blinding. An uncontrolled before-after study evaluating copper-impregnated textiles in a long-term care ward demonstrated 24% reduction in HCAI but was considered very-low-quality evidence based on the study design. Copper surfaces used in clinical settings result in modest reductions in microbial contamination. One study of copper surfaces and one of copper textiles demonstrated reduction in HCAI, but both were at high risk of bias.

Early diagnosis of SARS: lessons from the Toronto SARS outbreak

The clinical presentation of SARS is nonspecific and diagnostic tests do not provide accurate results early in the disease course. Initial diagnosis remains reliant on clinical assessment. To identify features of the clinical assessment that are useful in SARS diagnosis, the exposure status and the prevalence and timing of symptoms, signs, laboratory and radiographic findings were determined for all adult patients admitted with suspected SARS during the Toronto SARS outbreak. Findings were compared between patients with laboratory-confirmed SARS and those in whom SARS was excluded by laboratory or public health investigation. Of 364 cases, 273 (75%) had confirmed SARS, 30 (8%) were excluded, and 61 (17%) remained indeterminate. Among confirmed cases, exposure occurred in the healthcare environment (80%) or in the households of affected patients (17%); community or travel-related cases were rare (<3%). Fever occurred in 97% of patients by the time of admission. Respiratory findings including cough, dyspnea and pulmonary infiltrates evolved later and were present in only 59, 37 and 68% of patients, respectively, at admission. Direct exposure, fever on the first day of illness, and elevated temperature, pulmonary infiltrates, lymphopenia and thrombocytopenia at admission were associated with confirmed cases. Rhinorrhea, sore throat, and an elevated neutrophil count at admission were associated with excluded cases. In the absence of fever or significant exposure, SARS is unlikely. Other clinical, laboratory and radiographic findings further raise or lower the likelihood of SARS and provide a rational basis for estimating the likelihood of SARS and directing initial management.

Trimethoprim-sulfamethoxazole induced aseptic meningitis in a renal transplant patient

A 45-year-old man underwent renal transplant for end-stage renal disease complicating systemic lupus erythematosis. Within 24 hours of initiating Pneumocystis carinii pneumonia (PCP) prophylaxis with trimethoprim-sulfamethoxazole (TMP-SMX) he developed fever and confusion. Cerebrospinal fluid examination revealed a pleocytosis but cultures were negative. The patient improved within three days after cessation of the TMP-SMX but symptoms recurred rapidly upon drug rechallenge. Drug-induced aseptic meningitis is an uncommon but well described clinical entity. This is the first case described in a patient following renal transplantation. The literature is reviewed and the clinical features, diagnostic challenges and possible mechanisms of TMP-SMX-induced aseptic meningitis are discussed. This problem may be more common in the transplant population than is recognized given the difficulty of diagnosis combined with the widespread use of TMP-SMX as PCP prophylaxis.