Prevalence of chronic infections and susceptibility to measles and varicella-zoster virus in Latin American immigrants

Large numbers of Latin American immigrants recently arrived in Western Europe. Curative and preventive programmes need to take account of their risk of suffering and transmitting imported chronic infections and of their susceptibility to cosmopolitan infections. We aimed to assess the prevalence and co-occurrence of imported chronic infections among Latin American immigrants, and their susceptibility to highly prevalent cosmopolitan infections

Vaccine immunity in patients with 22q11.2 microdeletion syndrome

Background: Patients with microdeletion 22q11.2 syndrome (MDS) exhibit immunological defects, characterized by abnormalities in the development of the thymus, which plays a crucial role in T-cell maturation and immune response. As a result, these patients may have impaired adaptive immunity, with decreased responses to vaccination. Methods: This was a prospective observational study. Vaccine serology (tetanus, diphtheria, Haemophilus influenzae type b for children &lt;5 years, measles, varicella, hepatitis A and B, and SARS-CoV-2) and immune parameters were assessed in MDS patients aged between 1 and 25 years followed in Geneva between February 2022 and April 2023. Results: 41 MDS patients were included. The median age was 13 years old. Most of them reported recurrent otitis and bronchitis up to 10 years, and a mild COVID-19 disease in the past. Immunological work-up indicated normal immunoglobulin levels and lymphocyte counts for the majority. Most patients were well vaccinated for tetanus, diphtheria, Haemophilus influenzae type b and measles, but only half were fully vaccinated for hepatitis B, and SARS-CoV-2 and only a quarter for hepatitis A. 70% of the patients had received 3 doses of pneumococcal conjugate vaccine in infancy but only a minority an additional dose. While most of them were seroprotected against tetanus, diphtheria, and Hib, a substantial number lacked seroprotection against varicella, measles, hepatitis B, and pneumococcus. Conclusion: This study suggests that regular assessment of antibody levels for measles, hepatitis B, varicella, and pneumococcus, regardless of vaccination status should be encouraged in MDS patients, with reimmunization according to vaccine serology, to enhance vaccine immunity.</p

SARS-CoV-2 convalescence and hybrid immunity elicits mucosal immune responses

AbstractMucosal antibodies play a key role in the protection against SARS-CoV-2 infection in the upper respiratory tract, and potentially in limiting virus replication and therefore onward transmission. While systemic immunity to SARS-CoV-2 is well understood, little is known about the antibodies present on the nasal mucosal surfaces.In this study, we evaluated SARS-CoV-2 mucosal antibodies in response to infection, vaccination, or a combination of both. Paired nasal fluid and serum samples were collected from 136 individuals, which include convalescent, vaccinated, or breakthrough infections.We detected a high correlation between IgG responses in serum and nasal fluids, which were higher in both compartments in vaccinated compared to convalescent participants. Contrary, nasal and systemic SARS-CoV-2 IgA responses were weakly correlated, indicating a compartmentalization between the local and systemic IgA responses. SARS-CoV-2 secretory component IgA (s-IgA) antibodies, present exclusively on mucosal surfaces, were detected in the nasal fluid only in a minority of vaccinated subjects and were significantly higher in previously infected individuals. s-IgA binding antibodies showed significant correlation with neutralizing activity of nasal fluids against SARS-CoV-2 ancestral B.1 and Omicron-BA.5 variant, indicating that s-IgA is the crucial contributor to neutralization in the nasal mucosa. Neutralization against both SARS-CoV-2 strains was higher in the mucosa of subjects with previous SARS-CoV-2 infections compared to vaccinated participants.In summary, we demonstrate that currently available vaccines elicit strong systemic antibody responses, but SARS-CoV-2 infection generates more potent binding and neutralizing mucosal antibodies. Our results support the importance to develop SARS-CoV-2 vaccines that elicit mucosal antibodies.One Sentence SummarySARS-CoV-2 infection or combination of infection and vaccination (hybrid immunity) elicit binding and functional mucosal antibody responses superior of those after systemic vaccination.</jats:sec

Severe acute respiratory coronavirus virus 2 (SARS-CoV-2) seroconversion and occupational exposure of employees at a Swiss university hospital: A large longitudinal cohort study

AbstractBackground:The dynamics of coronavirus disease 2019 (COVID-19) seroconversion of hospital employees are understudied. We measured the proportion of seroconverted employees and evaluated risk factors for seroconversion during the first pandemic wave.Methods:In this prospective cohort study, we recruited Geneva University Hospitals employees and sampled them 3 times, every 3 weeks from March 30 to June 12, 2020. We measured the proportion of seroconverted employees and determined prevalence ratios of risk factors for seroconversion using multivariate mixed-effects Poisson regression models.Results:Overall, 3,421 participants (29% of all employees) were included, with 92% follow-up. The proportion of seroconverted employees increased from 4.4% (95% confidence interval [CI], 3.7%–5.1%) at baseline to 8.5% [(95% CI, 7.6%–9.5%) at the last visit. The proportions of seroconverted employees working in COVID-19 geriatrics and rehabilitation (G&amp;R) wards (32.3%) and non–COVID-19 G&amp;R wards (12.3%) were higher compared to office workers (4.9%) at the last visit. Only nursing assistants had a significantly higher risk of seroconversion compared to office workers (11.7% vs 4.9%; P = .006). Significant risk factors for seroconversion included the use of public transportation (adjusted prevalence ratio, 1.59; 95% CI, 1.25–2.03), known community exposure to severe acute respiratory coronavirus virus 2 (2.80; 95% CI, 2.22–3.54), working in a ward with a nosocomial COVID outbreak (2.93; 95% CI, 2.27–3.79), and working in a COVID-19 G&amp;R ward (3.47; 95% CI, 2.45–4.91) or a non–COVID-19 G&amp;R ward (1.96; 95% CI, 1.46–2.63). We observed an association between reported use of respirators and lower risk of seroconversion (0.73; 95% CI, 0.55–0.96).Conclusion:Additional preventive measures should be implemented to protect employees in G&amp;R wards. Randomized trials on the protective effect of respirators are urgently needed.</jats:sec

Additional file 1: of Prevalence of chronic infections and susceptibility to measles and varicella-zoster virus in Latin American immigrants

Multilingual abstracts in the five official working languages of the United Nations. (PDF 384 kb

Severe acute respiratory coronavirus virus 2 (SARS-CoV-2) seroconversion and occupational exposure of employees at a Swiss university hospital: A large longitudinal cohort study

The dynamics of coronavirus disease 2019 (COVID-19) seroconversion of hospital employees are understudied. We measured the proportion of seroconverted employees and evaluated risk factors for seroconversion during the first pandemic wave

Head-to-Head Evaluation of Five Automated SARS-CoV-2 Serology Immunoassays in Various Prevalence Settings

Purpose: To assess the diagnostic performances of five automated anti-SARS-CoV-2 immunoassays, Epitope (N), Diasorin (S1/S2), Euroimmun (S1), Roche N (N), and Roche S (S-RBD), and to provide a testing strategy based on pre-test probability. Methods: We assessed the receiver operating characteristic (ROC) areas under the curve (AUC) values, along with the sensitivity, specificity, positive predictive values (PPVs), and negative predictive values (NPVs), of each assay using a validation sample set of 172 COVID-19 sera and 185 negative controls against a validated S1-immunofluorescence as a reference method. The three assays displaying the highest AUCs were selected for further serodetection of 2033 sera of a large population-based cohort. Results: In the validation analysis (pre-test probability: 48.1%), Roche N, Roche S and Euroimmun showed the highest discriminant accuracy (AUCs: 0.99, 0.98, and 0.98) with PPVs and NPVs above 96% and 94%, respectively. In the population-based cohort (pre-test probability: 6.2%) these three assays displayed AUCs above 0.97 and PPVs and NPVs above 90.5% and 99.4%, respectively. A sequential strategy using an anti-S assay as screening test and an anti-N as confirmatory assays resulted in a 96.7% PPV and 99.5% NPV, respectively. Conclusions: Euroimmun and both Roche assays performed equally well in high pre-test probability settings. At a lower prevalence, sequentially combining anti-S and anti-N assays resulted in the optimal trade-off between diagnostic performances and operational considerations.</jats:p