Endimiani, Andrea

AbstractIn a COVID‐19 sero‐surveillance cohort study with predominantly healthy and vaccinated individuals, the objectives were (i) to investigate longitudinally the factors associated with the quantitative dynamics of antispike (anti‐S1) IgG antibody levels, (ii) to evaluate whether the levels were associated with protection from SARS‐CoV‐2 infection, and (iii) to assess whether the association was different in the pre‐Omicron compared with the Omicron period. The QuantiVac Euroimmun ELISA test was used to quantify anti‐S1 IgG levels. The entire study period (16 months), the 11‐month pre‐Omicron period and the cross‐sectional analysis before the Omicron surge included 3219, 2310, and 895 reactive serum samples from 949, 919, and 895 individuals, respectively. Mixed‐effect linear, mixed‐effect time‐to‐event, and logistic regression models were used to achieve the objectives. Age and time since infection or vaccination were the only factors associated with a decline of anti‐S1 IgG levels. Higher antibody levels were significantly associated with protection from SARS‐CoV‐2 infection (0.89, 95% confidence interval [CI] 0.82–0.97), and the association was higher during the time period when Omicron was predominantly circulating compared with the ones when Alpha and Delta variants were predominant (adjusted hazard ratio for interaction 0.66, 95% CI 0.53–0.84). In a prediction model, it was estimated that >8000 BAU/mL anti‐S1 IgG was required to reduce the risk of infection with Omicron variants by approximately 20%–30% for 90 days. Though, such high levels were only found in 1.9% of the samples before the Omicron surge, and they were not durable for 3 months. Anti‐S1 IgG antibody levels are statistically associated with protection from SARS‐CoV‐2 infection. However, the prediction impact of the antibody level findings on infection protection is limited.

The recommended empiric ceftriaxone dosing regimen for acute bacterial meningitis in adults is 2 g every 12 h. After penicillin-susceptible Streptococcus pneumoniae is isolated as a causative microorganism, the ceftriaxone dose may be continued or reduced to a single dose of 2 g every 24 h, per institutional preference. There is no clear guidance that indicates the superiority of one regimen over the other. The objective of this study was to evaluate the susceptibility of S. pneumoniae in the cerebral spinal fluid (CSF) of patients with meningitis and the relationship between ceftriaxone dose and clinical outcomes. We identified 52 patients with S. pneumoniae meningitis with positive CSF cultures who were treated at the University Hospital, Bern, Switzerland, over a 19-year period. We collected clinical and microbiological data for evaluation. Broth microdilution and Etest methods were performed to test penicillin and ceftriaxone susceptibility. All isolates were susceptible to ceftriaxone. Ceftriaxone was empirically used in 50 patients, with a starting dosing regimen of 2 g every 24 h in 15 patients and 2 g every 12 h in 35 patients. In 32 patients started on a twice-daily regimen (91%), doses were reduced to once daily after a median of 1.5 (95% CI 1–2) days. The overall in-hospital mortality was 15.4% (n = 8), and 45.7% of patients reported at least one sequela of meningitis at the last follow-up (median 375, 95% CI 189–1585 days). We found no statistical difference in outcome between the 2 g every 24 h and the 2 g every 12 h ceftriaxone dosing regimens. A ceftriaxone total daily dose of 2 g may be associated with similar outcomes to a 4 g total daily dose, provided that the causative organism is highly susceptible to ceftriaxone. The persistence of neurological and infection sequelae at the last follow-up underscores the need for optimal treatment of these complex infections.

Objectives In a COVID-19 sero-surveillance cohort study with predominantly healthy and vaccinated individuals, the objectives were (i) to investigate longitudinally the factors associated with the quantitative dynamics of anti-spike IgG antibody levels, (ii) to evaluate whether the antibody levels were associated with protection from SARS-CoV-2 infection and (iii) to assess whether the association was different in the pre-Omicron compared with the Omicron period. Methods The QuantiVac Euroimmun ELISA test was used to quantify anti-S1 IgG levels. The entire study period (16 months), the 11-month pre-Omicron period and the cross-sectional analysis prior to the Omicron surge included 3219, 2310 and 895 reactive serum samples from 949, 919 and 895 study participants, respectively. Mixed-effect linear, mixed-effect time-to-event and logistic regression models were used to achieve the objectives. Results Age and time since infection or vaccination were the only factors associated with a decline of anti-S1 IgG levels. Antibody levels were significantly associated with protection from SARS-CoV-2 infection, and the association was higher for the Omicron than for the Alpha and Delta variants. In a prediction model, it was estimated that >8000 BAU/mL anti-S1 IgG was required to reduce the risk of infection with Omicron variants by 20% to 30% for 90 days. Conclusions Anti-S1 IgG antibody levels are associated with protection from infection. The levels in the pre-Omicron periods were less significant than during the Omicron surge, which in turn required very high levels for protection in a statistical model.

AbstractIntroductionTo assess the risk for COVID‐19 of police officers, we are studying the seroprevalence in a cohort. The baseline cross‐sectional investigation was performed before a vaccination campaign in January/February 2021, and demonstrated a seroprevalence of 12.9%. Here, we demonstrate serosurveillance results after a vaccination campaign.MethodsThe cohort consists of 1022 study participants. The 3‐ and 6‐month follow‐up visits were performed in April/May and September 2021. Data on infection and vaccination rates were obtained via measuring antibodies to the nucleocapsid protein and spike protein and online questionnaires.ResultsThe mean age of the population was 41 (SD 8.8) years, 72% were male and 76% had no comorbidity. Seroconversion was identified in 1.05% of the study population at the 3‐month visit and in 0.73% at the 6‐month visit, resulting in an infection rate of 1.8% over a time period of 6 months. In comparison, the infection rate in the general population over the same time period was higher (3.18%, p = .018). At the 6‐month visit, 77.8% of participants reported being vaccinated once and 70.5% twice; 81% had an anti‐S antibody titer of >250 U/ml and 87.1% of ≥2 U/ml. No significant association between infection and job role within the department, working region, or years of experience in the job was found. Anti‐spike antibody titers of vaccinated study participants showed a calculated decreasing trend 150–200 days after the second vaccine dose.ConclusionThese data confirm the value of the vaccination campaign in an exposed group other than healthcare professionals.