People living with HIV (PLWH) are known to maintain a degree of immune deficiency despite efficient antiretroviral therapy and may exhibit diminished responses to vaccines. In this study, we assessed the immune response to SARS-CoV-2 infection and vaccines in two geographically distinct PLWH populations. PLWH and HIV-negative (HIV-) participants were recruited from Qu&bec City (QC), Canada, and Bobo-Dioulasso (BD), Burkina Faso, for two visits at 24-week intervals during the predominance of the Omicron variant, from May 2022 to September 2023. Blood samples were collected at each visit for the detection of antibodies against spike (anti-S) and nucleocapsid (anti-N) proteins of SARS-CoV-2 in platelet-free plasma. A total of 360 participants were enrolled. We detected anti-S antibodies in 99% of participants, indicating that nearly all had prior exposure to the SARS-CoV-2 spike antigen, either through vaccination or prior infection. Anti-S titers showed no difference between PLWH and HIV& participants in each location, while significantly higher titers were observed in participants from QC compared to BD. In contrast, anti-N antibodies, indicative of prior infection, were detected in 39% and 86% of the participants in QC and BD, respectively, suggesting that the virus circulated largely in the latter population. No difference in anti-N levels was observed between PLWH and HIV& participants in BD. However, participants in QC had significantly lower titers compared to HIV participants. Overall, this study shows that PLWH develop robust antibody responses to SARS-CoV-2 vaccination, comparable to those observed in HIV& participants. Significant geographic differences were observed in anti-S titers, irrespective of HIV status, with participants from QC displaying higher titers. In contrast, participants from BD had higher anti-N antibody prevalence and titers, reflecting more SARS-CoV-2 infections in BD than in QC. Finally, analysis of anti-S antibody titers against several circulating variants revealed significantly lower levels in unvaccinated participants and in those vaccinated with monovalent vaccines in BD. No significant difference was observed between monovalent and bivalent vaccines administered in QC. All authors have seen and approved the manuscript. ### Competing Interest Statement The authors have declared no competing interest. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The study was approved by the ethics committee of the "Centre de recherche du CHU de Québec-Université Laval" (registration number CER-2022-6241) and the Burkina Faso Ministry of Health Research Ethics Committee (Deliberation n°2022-03-048). I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes The study protocol, results and informed consent documents will be made available to researchers upon request from the corresponding author. Researchers will be asked to complete a concept sheet for their proposed analyses to be reviewed, and the investigators will consider the overlap of the proposed project with active or planned analyses and the appropriateness of the study data for the proposed analysis. Canadian Institutes of Health Research (CIHR), Emerging COVID-19 Research Gaps & Priorities (July 2021) - HIV and SARS-CoV-2, EGS-179454

Substantial inter-individual variation in susceptibility to viral infection persists despite widespread vaccination, and its immunological basis remains poorly understood. We investigated how innate and adaptive immune responses contribute to susceptibility to SARS-CoV-2 infection during the early COVID-19 pandemic. We compared two groups of vaccinated individuals who either remained uninfected or became infected during the first Omicron wave. Blood samples were collected at baseline and 24 weeks later. Peripheral blood mononuclear cells (PBMCs) and polymorphonuclear neutrophils (PMNs) were isolated and stimulated with the TLR7/8 agonist R848 to assess innate responses. PBMCs were stimulated with SARS-CoV-2 peptide pools and highly purified inactivated viruses (ancestral and Omicron BA.1) to evaluate adaptive immunity. Prior to infection, individuals in the infected group exhibited reduced CD4 and CD8 T cells proliferative responses, alongside with increased TNF production across all stimulation conditions, despite largely comparable immune phenotypes, indicating a pre-existing functional immune deficit. Following infection, T-cell proliferation and IFN-gamma production were partially restored in response to viral antigens, although responses to Omicron BA.1 remained suboptimal. This functional deficit was accompanied by heightened inflammatory activity, including increased TNF and IFN-gamma production, elevated anti-nucleocapsid IgG3 levels, higher frequencies of B cells and myeloid cells, reduced circulating interferon-inducible T-cell Alpha Chemoattractant (I-TAC) concentrations, and a modest impairment in PMN IL-8 responses. Notably, these alterations were detectable prior to infection and persisted thereafter, indicating that they represent determinants rather than consequences of viral infection. Importantly, beyond differences in the magnitude of immune responses, protection was associated with the degree of functional coordination within the humoral compartment, as reflected by the relationship between Spike-binding antibodies and neutralizing activity. Together, these results demonstrate that susceptibility to Omicron infection is linked to a pre-existing and persistent functional immune imbalance affecting both innate and adaptive arms of immunity.

BACKGROUND:Enterovirus D68 (EV-D68) causes acute respiratory illnesses and has also implicated in acute flaccid myelitis. Neutralizing antibodies (NtAbs) represent key components of the adaptative immunity. However, the dynamics of EV-D68 NtAbs in adults remain poorly characterized. We evaluated EV-D68 NtAb levels in retail workers in Canada during the COVID-19 pandemic. METHODS:NtAbs were measured in paired serum samples (N = 194), from retail workers (≥18 years) enrolled in a prospective SARS-CoV-2 cohort at the Centre Hospitalier Universitaire de Québec-Université Laval, in Quebec City. Samples collected 48 weeks apart, between June 2021 to October 2022, were tested by microneutralization assays. RESULTS:EV-D68 NtAb seroprevalence was high (>85%). Over the 48-weeks follow-up, the vast majority of patients (97%) had stable or reduced titers with a statistically significant overall reduction in geometric mean titer (GMT), P < 0.001. Furthermore, a small subset of participants 6/194 (3%) showed a marked increase of titers (≥4-fold) with the GMT rising from 21 (10-57) at the first visit to 593 (57-7241) at follow-up visit. CONCLUSIONS:Neutralizing antibody titers declined in most participants over 48 weeks. However, six individuals had significantly increased NtAb titers during the study period, which is consistent with potential ongoing EV-D68 or other enterovirus circulation in Quebec following sequential non-pharmaceutical interventions lift. This is in line with documented EV-D68 resurgence in the United States at the same period. Our work complements pediatric data on EV-D68 immunity and highlights the serological surveillance importance in adults.

BACKGROUND:Human papillomavirus (HPV) testing has been implemented in many organized cervix screening programs; however, understanding how this screening methodology affects rates of colposcopy and further follow-up procedures remains underexplored, especially among women with HIV. In the absence of HPV screening program data in British Columbia (BC), Canada, we sought to determine HPV prevalence and estimates for colposcopies among a cohort of women with HIV using the BC Cervix Screening algorithm. SETTING:HPV data were collected and analyzed from a prospective HPV vaccine immunogenicity cohort study of women with HIV from 14 sites of HIV care across Canada from 2008 to 2015. METHODS:HPV data were obtained during the screening (month -3), baseline (month 0), month 12, and month 24 time points (Linear Array assay). Participant demographic and clinical characteristics (CD4 + count, HIV viral load, etc.) were assessed to determine associations between HPV prevalence and estimates for colposcopy using rate ratios and 95% confidence intervals. RESULTS:Overall, 47.2% of participants had oncogenic HPV detected at screening which would result in a colposcopy referral. In total, 15.9% of participants had oncogenic HPV detected at screening, month 12, and month 24 time points, which would result in 3 consecutive referrals to colposcopy. Participants with repeat oncogenic HPV detected were less likely to have a suppressed HIV viral load compared with participants without oncogenic HPV detected. CONCLUSIONS:Results of this study suggest that HPV testing will result in a high proportion of referrals to colposcopy and follow-up procedures among women with HIV, which will require preparation and planning. Further work is needed to provide the appropriate support and education for women with HIV when incorporating HPV testing into cervix screening programs.

The landscape of infectious diseases has dramatically evolved since the 1970s and the advent of antimicrobials, which heralded a new era in medical history [...]

IntroductionThe innate immune response is an important first checkpoint in the evolution of an infection. Although adaptive immunity is generally considered the immune component that retains antigenic memory, innate immune responses can also be affected by previous stimulations. This study evaluated the impact of vaccination on innate cell activation by TLR7/8 agonist R848, as well as seasonal variations.MethodsTo this end, blood samples from a cohort of 304 food and retail workers from the Quebec City region were collected during three visits at 12-week intervals. Peripheral blood mononuclear cells and polymorphonuclear neutrophils were isolated during the first and third visits and were stimulated with R848 to assess the innate immune response.ResultsOur results show that IL-8 production after stimulation decreased after vaccination. In addition, the IL-8 response was significantly different depending on the season when the visit occurred, for both COVID-19 vaccinated and unvaccinated individuals.DiscussionThis study highlights that innate immune responses can be affected by SARS-CoV-2 vaccination and fluctuate seasonally.

Background/Objectives: Retail workers may have been at an increased risk of contracting SARS-CoV-2 during the COVID-19 pandemic. To better understand this group, we set up a longitudinal cohort to document the occurrence of SARS-CoV-2 infection, vaccination uptake and to study immune response. Methods: Participants were enrolled between 20 April and 22 October 2021 and attended up to 5 visits over 48 weeks. Information collected was: participant characteristics, SARS-CoV-2 detection tests performed, COVID-19 symptoms, and vaccination (influenza and SARS-CoV-2). Findings: We included 304 participants aged 18 to 75; of those, 117 had a first positive SARS-CoV-2 test, mostly (85.5%) during Omicron wave. Forty-two (13.8%) participants got seasonal influenza vaccine within the year (2020–2021) prior to the first visit, and 95.9% had received the primary series of 2 doses of SARS-CoV-2 vaccine by the beginning of Omicron wave. Participants vaccinated for influenza (adjusted hazard ratio (aHR) 2.48; 95% confidence interval (CI): 1.54–3.98) and older patients (aHR 2.39; 95% CI: 1.40–4.10), were more likely to get a first booster of SARS-CoV-2 vaccine compared to those who did not receive influenza vaccine. In contrast, participants who traveled (aHR 0,62; 95% CI: 0.43–0.91) or participated in frequent gatherings (aHR 0.58; 95% CI: 0.39–0.85) were less likely to be boosted. Conclusions: Variations in vaccine uptake that are usually observed within populations had little effect on completion of the primary SARS-CoV-2 vaccine series. However, these differences became apparent for booster doses, at a period during which most infections in this cohort were recorded.

This study evaluated whether immunity from seasonal influenza induces cross-reactive antibodies against recent avian and bovine H5N1 strains in serum from retail workers. Despite strong neutralizing activity against seasonal strains, no cross-reactivity against H5N1 was detected, emphasizing the need to assess broader immune responses and targeted vaccines for H5N1 viruses.

Background/Objectives: Enterovirus-D68 (EV-D68) and rhinoviruses are major contributors to respiratory illnesses in children, presenting a spectrum of clinical manifestations ranging from asymptomatic cases to severe lower respiratory tract infections. No specific antiviral treatments are currently approved for these viruses. Method: We conducted a comprehensive literature review of antiviral agents investigated for EV-D68 and rhinovirus infections. Results: Several antiviral candidates are under investigation, each targeting distinct stages of the viral replicative cycle. Capsid-binding agents and monoclonal antibodies prevent viral attachment by blocking receptor-virus interactions. Inhibitors of viral replication proteins disrupt polyprotein processing and replication organelle biogenesis by targeting non-structural viral proteins. Host factor inhibitors impair viral attachment, replication organelle formation, or RNA replication by interfering with critical host pathways. Conclusions: While no specific antivirals are yet approved for EV-D68 and rhinovirus infections, emerging therapeutic candidates offer potential avenues for treatment. Continued preclinical and clinical investigation will be essential to validate these approaches and expand the available options for affected patients.

Background. Oseltamivir is recommended for the treatment of adults hospitalized with influenza, but adherence is often suboptimal. This may be due to doubts about the reliability of the evidence supporting its benefits, particularly when initiation is delayed. We aimed to assess the effectiveness of oseltamivir in reducing mortality in older adults hospitalized with influenza, with a focus on the timing of initiation. Methods. The CIRN-SOS Network gathered data on severe respiratory illnesses across 5 Canadian provinces during the influenza seasons 2012-2019. Individuals aged >= 65 years with confirmed influenza and available antiviral prescription data were included. We compared the 30-day survival rates of hospitalized patients based on oseltamivir prescription status. Kaplan-Meier estimated survival probability and inverse probability of treatment (IPT)-weighted Cox proportional hazard models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for mortality. The analyses considered the time to antiviral initiation (>48 vs <= 48 hours). Results. Among the 8135 influenza patients studied, 2126 did not receive antiviral treatment, whereas 6009 were treated with oseltamivir. A total of 395 patients were hospitalized for >30 days. The overall mortality rate was 8.32 per 1000 person-days, with 53.9% of the deaths occurring within the first week. Oseltamivir recipients had a 18% lower risk of 30-day mortality (IPT-weighted HR, 0.82 [95% CI, .69-.98]). The benefit was significant for influenza A (IPT-weighted HR, 0.74 [95% CI, .61-.91]) but not for influenza B (IPT-weighted HR, 1.12 [95% CI, .81-1.56]). Oseltamivir remained effective even when initiated after 48 hours (IPT-weighted HR, 0.66 [95% CI, .49-.90]). Influenza vaccination did not mediate the effectiveness of oseltamivir in reducing mortality. Conclusions. Oseltamivir significantly reduces mortality risk in older adults hospitalized with influenza, even when administered after 48 hours, independent of vaccination status.

Background/Objectives: Legionella micdadei is a clinically significant species within the Legionella genus, requiring accurate detection methods, surveillance, and precise clinical diagnosis. Our objective was to develop a sensitive polymerase chain reaction (PCR) assay specific for L. micdadei to detect its presence in environmental specimens. Methods: We targeted the 23S–5S intergenic spacer region, which can differentiate Legionella spp. We tested the detection of L. micdadei with 20 strains and determined the limit of detection with 2 strains. We verified assay specificity with 17 strains of other Legionella spp., 62 strains of other bacterial and fungal genera, and three human DNA specimens. We evaluated intra- and inter-run precision. We tested 15 environmental specimens (water, swabs of water faucets, mulch, and soil) by PCR. Results: The PCR assay demonstrated 100% analytical specificity (no cross-reactivity with non-targeted species), 100% inclusivity (detection of all L. micdadei strains), and high precision, with a coefficient of variation ≤ 2% across replicates. The limit of detection was estimated at 5 genomic DNA copies per reaction. We detected L. micdadei in environmental specimens. Conclusions: This PCR assay enables accurate detection of L. micdadei and is not subject to competition with other Legionella spp., thereby addressing limitations of current broad-spectrum Legionella approaches. The evaluation supports its application in environmental detection for surveillance.

Objectives:Enterovirus D68 (EV-D68) is mainly studied in children, while data in adults are limited. We described the clinical presentation of EV-D68 in adults, compared with other enterovirus/rhinovirus (EV/RV) infections. Methods:We used clinical and laboratory data from 1143 adults visiting four emergency departments in Quebec, Canada, for acute respiratory infections (February 2022 to March 2023). We analyzed nasopharyngeal swabs using a multiplex polymerase chain reaction; positive EV/RV samples were further tested with EV-D68-specific polymerase chain reaction assays. We calculated the Pandemic Medical Early Warning Score (PMEWS) to assess severity. Results:Of 155 (14%) EV/RV samples, 19 (12%) were EV-D68 and occurred from July to October, 2022. Patients with EV-D68 more frequently lived with other people (100% vs 73%, P = 0.02) and tended to have more underlying chronic respiratory diseases (26% vs 20%) and respiratory symptoms (e.g., dyspnea: 84% vs 75%; wheezing: 63% vs 44%; and chest pain: 63% vs 49%), although these differences were not statistically significant. PMEWS, hospitalizations, and median time spent in the emergency department did not differ significantly between the EV-D68 and the other EV/RV group. Conclusions:Respiratory symptoms tended to be more common among participants with EV-D68 than those with other EV/RV, although disease severity was similar. Larger studies are needed to better characterize EV-D68 infections in adults.

ABSTRACT The detection of Clostridioides difficile infections (CDI) relies on testing the stool of patients by toxin antigen detection or PCR methods. Although PCR and antigenic methods have significantly reduced the time to results, delays in stool collection can significantly add to the turnaround time. The use of rectal swabs to detect C. difficile could considerably reduce the time to diagnosis of CDI. We developed a new rapid PCR assay for the detection of C. difficile and evaluated this PCR assay on both stool and rectal swab specimens. We recruited a total of 623 patients suspected of C. difficile infection. Stool samples and rectal swabs were collected from each patient and tested by our PCR assay. Stool samples were also tested by the cell cytotoxicity neutralization assay (CCNA) as a reference. The PCR assay detected C. difficile in 60 stool specimens and 61 rectal swabs for the 64 patients whose stool samples were positive for C. difficile by CCNA. The PCR assay detected an additional 35 and 36 stool and rectal swab specimens positive for C. difficile , respectively, for sensitivity with stools and rectal swabs of 93.8% and 95.3%, specificity of 93.7% and 93.6%, positive predictive values of 63.2% and 62.9%, and negative predictive values of 99.2% and 99.4%. Detection of C. difficile using PCR on stools or rectal swabs yielded reliable and similar results. The use of PCR tests on rectal swabs could reduce turnaround time for CDI detection, thus improving CDI management and control of C. difficile transmission. IMPORTANCE Clostridioides difficile infection (CDI) is the leading cause of healthcare-associated diarrhea, resulting in high morbidity, mortality, and economic burden. In clinical laboratories, CDI testing is currently performed on stool samples collected from patients with diarrhea. However, the diagnosis of CDI can be delayed by the time required to collect stool samples. Barriers to sample collection could be overcome by using a rectal swab instead of a stool sample. Our study showed that CDI can be identified rapidly and reliably by a new PCR assay developed in our laboratory on both stool and rectal swab specimens. The use of PCR tests on rectal swabs could reduce the time for the detection of CDI and improve the management of this infection. It should also provide a useful alternative for infection-control practitioners to better control the spread of C. difficile .

Since the onset of the global pandemic caused by the emergence and spread of SARS-CoV-2 in early 2020, numerous studies have been conducted worldwide to understand our immune response to the virus. This study investigates the humoral response elicited by vaccination and by SARS-CoV-2 infection in the poorly studied food and retail workers in the Québec City area. The 1.5-year study period spans from early 2021, when vaccination became available in this region, to mid-2022, following waves of virulence due to the emergence of the first Omicron variants. Cross-correlated with data on workplace protective measures, pre-existing conditions, activities and other potentially relevant factors, this longitudinal study applies recently developed ELISA data transformation to our dataset to obtain normal distribution. This unlocked the possibility to use the ANOVA-Welsh method for statistical analysis to obtain a statistical perspective of the serological response. Our work allows the identification of factors contributing to statistically relevant differences in the humoral response of the cohort and strengthens the utility of the use of decentralized approaches to serological analysis.### Competing Interest StatementThe authors have declared no competing interest.### Funding StatementThis study was funded by the Public Health Agency of Canada through the COVID‐19 Immunity Task Force (CITF) grant number 2021-HQ-000134. Viral antigen production at the National Research Council of Canada (NRC) and in-kind support to MAL were supported by the NRC Pandemic Response Challenge Program. This research was supported in part by Canada Research Chair CRC-2020-00171 to JNP and by the Sentinel North Research Chair at Universite Laval (funded by the Canada First Research Excellence Fund) as well as by the Canada Research Chair CRC-2022-00103 to MB.### Author DeclarationsI confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.YesThe details of the IRB/oversight body that provided approval or exemption for the research described are given below:The Comite ethique de la recherche of the Centre Hospitalier Universitaire de Quebec-Universite Laval gave ethical approval for this work with registration number 2021-5744I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.YesI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).YesI have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.YesAll data produced in the present study are available upon reasonable request to the authors.

Background Since the onset of the global COVID-19 pandemic in early 2020, numerous studies have been conducted worldwide to understand our immune response to the virus and to vaccination. This study investigates the humoral response elicited by SARS-CoV-2 infection and by vaccination in the poorly studied population of food and retail workers. These occupations were classified as essential by the Public Health Agency of Canada, potentially placing this population at greater risk of infection. Such a risk requires access to reliable and adaptable serological assays that can be rapidly deployed to guide public health strategies. Here we investigate the benefits and limitations of applying adaptable, decentralized tests for population-level immune surveillance in response to a pandemic, even before centralized testing is available. Methods and findings The 1.5-year study period spans from early 2021, when vaccination became available in this region, to mid-2022, following the emergence of the first Omicron variants. The cohort of 304 food and retail workers was recruited in the Québec City area. Participants attended five evenly spaced visits, providing blood samples as well as information on SARS-CoV-2 symptoms or risk factors, prior antigen or PCR test results and vaccination status, as well as work-related risk factors and protective measures. Parallel COVID-19 serological assays were performed using both a standardized chemiluminescent ELISA assay at the centralized platform operated in partnership with the Public Health Agency of Canada, and a semi-automated in-house colorimetric ELISA assay developed at our decentralized site. The YES/NO determination of SARS-CoV-2 vaccine seroconversion and/or infection events using the SARS-CoV-2 ancestral spike protein and nucleocapsid protein validated coherence of the centralized and decentralized assays. The flexibility of the decentralized assays allowed broadening the study to determine cross-reactivity of IgG directed against the spike protein of the SARS-CoV-2 Delta and Omicron VOCs, and IgM directed against the ancestral spike and nucleocapsid proteins. The nature of the data obtained in the decentralized assays allowed treatment with a recently developed mathematical transformation to obtain normal distribution, enabling ANOVA-Welsh statistical analysis. Although no significant differences were observed in humoral response as related to BMI, age, level of education, or chronic illnesses in this cohort of workers, statistically higher levels of vaccine-induced antibodies were observed for restaurant workers and hardware store workers in the early stages of the study, compared to workers in bars and grocery stores and in non-smokers versus smokers. Conclusions This work highlights the importance of developing adaptable, decentralized tests for population-level immune surveillance in response to a pandemic, even before centralized testing is available. To our knowledge, no other study has reported such an extensive longitudinal investigation during key periods of the COVID-19 pandemic in a cohort of food and retail workers to analyze two types of immunoglobulin, three epitopes and antigens to three VOC. This study will inform strategies and measures to be implemented in the event of a future pandemic.

BackgroundMeasuring the ability of SARS-CoV-2 antibodies to neutralize live viruses remains an effective approach to quantify the level of protection of individuals. We assessed the neutralization activity against the ancestral SARS-CoV-2, Delta, Omicron BA.1, BA.2, BA.2.12.1, BA.4 and BA.5 strains, in 280 vaccinated restaurant/bar, grocery and hardware store workers in Québec, Canada.MethodsParticipants were recruited during the emergence of Omicron BA.1 variant. The neutralizing activity of participant sera was assessed by microneutralization assay.ResultsSerum neutralizing antibody (NtAb) titers of all participants against the ancestral SARS-CoV-2 strain were comparable with those against Delta variant (ranges of titers 10-2032 and 10-2560, respectively), however, their response was significantly reduced against Omicron BA.1, BA2, BA.2.12.1, BA.4 and BA.5 (10-1016, 10-1016, 10-320, 10-80 and 10-254, respectively). Individuals who received 2 doses of vaccine had significantly reduced NtAb titers against all SARS-CoV-2 strains compared to those infected and then vaccinated (≥1 dose), vaccinated (≥2 doses) and then infected, or those who received 3 doses of vaccine. Participants vaccinated with 2 or 3 doses of vaccine and then infected had the highest NtAb titers against all SARS-CoV-2 strains tested.ConclusionWe assessed for the first time the NtAb response in food and retail workers. We found that vaccination prior to the emergence of Omicron BA.1 was associated with higher neutralizing activity against pre-Omicron variants, suggesting the importance of updating vaccines to increase antibody response against new SARS-CoV-2 variants. Vaccination followed by infection was associated with higher neutralizing activity against all SARS-CoV-2 strains tested.

Men have a universal protection tool (male condom) under their control to protect themselves against sexually transmitted infections (STIs) including HIV/AIDS, and to avoid unintended pregnancy. Unfortunately, it is not consistently used. Male condom is used in only one-third of at-risk sexual intercourse by men 15–44 years of age. On the other hand, despite being up to 8 times more at risk of getting STIs during an unprotected vaginal intercourse, women have no means under their control to protect themselves as men do. In addition, they are vulnerable to unintended pregnancy that represents about 45% of all pregnancies (of more than 200 million pregnancies annually) around the globe. It is primordial to empower women with vaginal multipurpose prevention technologies (MPTs) to protect themselves during sexual intercourse when men do not use means of protection. Women need safe, effective, affordable and accessible vaginal protection. Protecting women will be beneficial, not only for them, but also for the whole society as well.

Background/Objectives: During the pandemic, client-facing workers were perceived to be at greater risk of SARS-CoV-2 infection. This study investigated the risk factors for SARS-CoV-2 infection among a cohort of 304 retail workers in the Quebec City metropolitan area. Methods: After providing consent, participants were interviewed to gather information on demographic, socioeconomic, behavioural, and occupational variables. They were subsequently followed for up to five visits, scheduled every 12 ± 4 weeks. The study covered critical periods before and during the emergence of the Omicron variants and included retrospective reporting of COVID-19 symptoms and virus detection tests to capture the pandemic’s early stages. Results: During the observation period, 173 (57%) participants experienced a first episode of COVID-19. Serological evidence of recent infection was detected in 160 participants (53%), while 117 (38%) reported a positive virus detection test. In adjusted analyses, risk factors for infection included younger age, a diagnosis of lung disease, longer weekly working hours, more frequent social gatherings, and having received fewer than three doses of vaccine. Notably, the increased risk associated with younger age and longer working hours was observed only after the relaxation of public health measures in the spring of 2022. Conclusions: These data suggest that during the early years of the pandemic when strict public health measures were in place, retail work was not a significant risk factor for SARS-CoV-2 infection in Quebec City metropolitan area. These findings highlight the complex dynamics of COVID-19 transmission and the effectiveness of workplace protective measures.

Background Chronic inflammation persists in some people living with human immunodeficiency virus (HIV) during antiretroviral therapy and is associated with premature aging. The glycoprotein 120 (gp120) subunit of HIV-1 envelope sheds and can be detected in plasma, showing immunomodulatory properties even in the absence of detectable viremia. We evaluated whether plasma soluble gp120 (sgp120) and a family of gp120-specific anti-cluster A antibodies, linked to CD4 depletion in vitro, contribute to chronic inflammation, immune dysfunction, and subclinical cardiovascular disease in participants of the Canadian HIV and Aging Cohort Study with undetectable viremia.Methods Cross-sectional assessment of sgp120 and anti-cluster A antibodies was performed in 386 individuals from the cohort. Their association with proinflammatory cytokines and subclinical coronary artery disease was assessed using linear regression models.Results High levels of sgp120 and anti-cluster A antibodies were inversely correlated with CD4+ T cell count and CD4/CD8 ratio. The presence of sgp120 was associated with increased levels of interleukin 6. In participants with detectable atherosclerotic plaque and detectable sgp120, anti-cluster A antibodies and their combination with sgp120 levels correlated positively with the total volume of atherosclerotic plaques.Conclusions This study showed that sgp120 may act as a pan toxin causing immune dysfunction and sustained inflammation in a subset of people living with HIV, contributing to the development of premature comorbid conditions. Soluble glycoprotein 120 (sgp120) is detected in the plasma of people living with HIV-1 with undetectable viremia. The presence of sgp120 and anti-cluster A antibodies is associated with correlates of immune dysfunction, chronic inflammation, and subclinical cardiovascular disease.

Plasmonic sensors are candidates for numerous clinical applications, but few examples demonstrate their performance on large sample cohorts, a necessary step for clinical translation. The COVID-19 pandemic provided an unprecedented opportunity to validate a surface plasmon resonance (SPR) sensor for SARS-CoV-2 inhibition with a cohort of over 1,000 clinical samples from the longitudinal study of a food and retail worker population. The SPR sensor provided an in vitro model to assess the level of neutralizing antibodies by measuring the inhibition of the SARS-CoV-2 spike protein interaction with ACE-2 following exposure of the spike protein to naive and immune sera (from vaccination and/or infection). In conjunction with population data on vaccination and infection, and epidemiological data from the local jurisdiction of the study cohort, it is shown that the SPR sensor performed well in assessing the level of “pseudo-neutralization” of participant sera and that the response of the SPR sensor correlates (r = 0.74) with a live virus microneutralization assay as well as with metadata of relevant events (vaccination, waves of infection, etc.) that occurred during the study period. Using these data, the article details the challenges and opportunities of using plasmonic sensors in clinical practice.