Explore the vast range of titles available.

Background: To provide updated estimates on SARS-CoV-2 antibody seroprevalence and average antibody titres for Central Europe. Methods: In repeat cross-sectional investigations (1 May 2022 to 9 March 2023) involving 28,768 blood donors in the Federal State of Tyrol, Austria (participation rate: 87.0%), we measured Spike receptor-binding domain (RBD) and Nucleocapsid IgG antibodies (37,065 and 12,645 samples), and estimated monthly seroprevalences and geometric mean titres. Results: Median age of participants was 45.4 years (range 18–70); 43.2% were female. Spike RBD IgG antibody seroprevalence was 96.3% (95% CI: 95.6–96.9%) in May 2022, 97.4% (96.7–98.0%) in December 2022, and 97.9% (96.4–98.8%) in March 2023. Among seropositive participants, geometric mean titres increased from 1400 BAU/mL (95% CI: 1333–1471) in May 2022 to 1821 BAU/mL (1717–1932) in December 2022, and dropped to 1559 BAU/mL (1405–1729) by March 2023. Furthermore, titres differed markedly by vaccination status and history of infection, with being the highest in participants with booster vaccination and prior infection. In autumn 2022, Nucleocapsid IgG antibody seroprevalence ranged from 36.5% (35.0–38.1) in September to 39.2% (37.2–41.2) in December 2022. Conclusion: Seroprevalence of SARS-CoV-2 antibodies in blood donors from Tyrol, Austria, was remarkably stable from May 2022 to March 2023. In contrast, average Spike RBD IgG antibody titres peaked in December 2022.

Background/Aim: Prompted by the increasing demand of non-invasive diagnostic tools for screening of gastric cancer (GC) risk conditions, i.e., atrophic gastritis (AG) and Helicobacter pylori (Hp) infection, the GastroPanel® test (GP: biomarker panel of PGI, PGII, G-17, Hp IgG ELISA) that was developed in the early 2000’s, was recently updated to a new-generation (unified GP) test version. This clinical validation study evaluated the diagnostic accuracy of the new-generation GP test in detection of AG and Hp among gastroscopy referral patients in a University Clinic. Patients and Methods: Altogether, 522 patients were enrolled among the patients referred for gastroscopy at the Gastro Center, Oulu University Hospital (OUH). All patients underwent gastroscopy with biopsies classified using the Updated Sydney System (USS), and blood sampling for GP testing. Results: Biopsy-confirmed AG was found in 10.2% (53/511) of the patients. The overall agreement between the GP and the USS classification was 92.4% (95%CI=90.0-94.6%), with the weighted kappa (κw) of 0.861 (95%CI=0.834-0.883). In ROC analysis using moderate/severe AG of the corpus (AGC2+) as the endpoint, AUC=0.952 (95%CI=0.891-1.000) and AUC=0.998 (95%CI=0.996-1.000) for PGI and PGI/PGII, respectively. Hp IgG antibody ELISA detected biopsy-confirmed Hp-infection with AUC=0.993 (95%CI=0.987-0.999). Conclusion: The new generation GastroPanel® is a precise test for non-invasive diagnosis of atrophic gastritis and Hp-infection in dyspeptic patients referred for diagnostic gastroscopy.

Developing convenient and accurate SARS-CoV-2 antigen test and serology test is crucial in curbing the global COVID-19 pandemic. In this work, we report an improved indium oxide (In 2 O 3 ) nanoribbon field-effect transistor (FET) biosensor platform detecting both SARS-CoV-2 antigen and antibody. Our FET biosensors, which were fabricated using a scalable and cost-efficient lithography-free process utilizing shadow masks, consist of an In 2 O 3 channel and a newly developed stable enzyme reporter. During the biosensing process, the phosphatase enzymatic reaction generated pH change of the solution, which was then detected and converted to electrical signal by our In 2 O 3 FETs. The biosensors applied phosphatase as enzyme reporter, which has a much better stability than the widely used urease in FET based biosensors. As proof-of-principle studies, we demonstrate the detection of SARS-CoV-2 spike protein in both phosphate-buffered saline (PBS) buffer and universal transport medium (UTM) (limit of detection [LoD]: 100 fg/mL). Following the SARS-CoV-2 antigen tests, we developed and characterized additional sensors aimed at SARS-CoV-2 IgG antibodies, which is important to trace past infection and vaccination. Our spike protein IgG antibody tests exhibit excellent detection limits in both PBS and human whole blood ((LoD): 1 pg/mL). Our biosensors display similar detection performance in different mediums, demonstrating that our biosensor approach is not limited by Debye screening from salts and can selectively detect biomarkers in physiological fluids. The newly selected enzyme for our platform performs much better performance and longer shelf life which will lead our biosensor platform to be capable for real clinical diagnosis usage.

Background The generalizability of the current quantitative assessments of age-specific RSV antibody levels remains unclear in China. We aimed to comprehensively understand the RSV immune profile at the population level and identify related factors. Methods We conducted a community-based cross-sectional sero-epidemiological study in Taizhou City, Eastern China, from June 2 to 30, 2024, and assessed RSV pre-F IgG antibody titres. We employed generalized linear models to identify factors linked to antibody titres and used a generalized additive model to determine RSV seropositivity risk. The serocatalytic model was further used to estimate the force of infection (FOI) based on age-specific seroprevalence data. Results Among 1303 individuals aged 16 months to 93 years, toddlers (younger than 2 years) had the lowest geometric mean titres (GMTs) of RSV pre-F IgG antibodies, which was 591.9 (95% confidence interval [CI], 106.5-3291.1). The GMTs increased annually by 2.038-fold (0.842–4.011), attaining a titre of 6133.9 (4639.3-8110.2) by the age of 4. The seroprevalence (using titre > 200 as the threshold) surged sharply with age, from 46.1% (42.2–50.2) at 1 year of age to 91.5% (88.9–93.8) at age 4, with an estimated FOI of 0.618 (0.547–0.697). Children residing in households with over four members correlated with a heightened risk of seropositivity within the first 4 postnatal year compared to those in households with four or fewer members (adjusted odds ratio, aOR: 1.954, 1.082–3.529). Age was significantly associated with GMTs in the elderly individuals (aged 65 and above), with an estimated annual increment of 0.019-fold (0.004–0.034). Elderly with underlying diseases demonstrated a 0.203-fold (0.036–0.341) reduction in GMTs compared to those without such conditions. Conclusions An early age-dependent pattern in RSV serostatus is observed, and the seroprevalence increased with age. Low antibody titres in early-life period and immunity impairment in the elderly due to underlying diseases emphasize the need to protect younger children and the elderly, from RSV infections. Clinical trial Not applicable.

Background This study evaluated SARS-CoV-2 infection rates among inbound international travelers to Uganda between May 2022 and July 2024, following the introduction of mandatory COVID-19 vaccination in March 2021. It also explored the relationship between traveler positivity rates and national COVID-19 trends. Methods We analyzed laboratory records of 4,517 inbound travelers tested at a laboratory which screens travelers at Entebbe International Airport. The testing algorithm included nucleic acid amplification testing (NAAT) for viral detection and chemiluminescent immunoassays to measure IgG antibody titers. Infection rates were stratified by vaccination status and age. To understand how vaccine- or infection-induced immunity might wane differently across age groups, impacting infection risk, we examined the interaction between IgG levels and age on PCR positivity and compared traveler positivity trends to national case data. Results The overall infection rate was 10.2% (461/4,517), with unvaccinated travelers having a significantly higher infection rate (13.1%; 253/1,935) than vaccinated ones (8.1%; 208/2,582). After adjusting for age and sex in a multivariate logistic regression analysis, vaccinated individuals had 42% lower odds of testing positive compared to those who were unvaccinated (Adjusted Odds Ratio: 0.58; 95% CI: 0.48–0.71; p  < 0.001). Protective IgG antibodies were present in 93.4% (2,412/2,582) of vaccinated individuals, compared to 6.1% (118/1,935) of the unvaccinated. PCR positivity was influenced by both age and IgG levels, with a non-linear interaction. Traveler positivity remained high across the study period, even as national case counts declined post-August 2022. Conclusion Vaccination significantly reduced infection risk and conferred higher IgG protection among travelers. The consistent high positivity among travelers, despite low national transmission, underscores the importance of continued surveillance at ports of entry as an early warning system, especially during global variant emergence. Clinical trial number Not applicable.

AbstractCurrently approved anti-COVID-19 vaccines have been found to be safe and effective and almost 60% of Israeli residents are already vaccinated with BNT162b2 vaccine. This observational study was designed to evaluate the adverse events of vaccine reported by 61 healthcare workers at least 7 days after the 2nd vaccination, and to investigate the correlation of adverse events and anti-SARS-CoV-2 IgG antibody levels. The median participant's age was 51.25 years, 16 men and 45 women; 77% (44% of male and 84.5% of female participants) reported adverse events. Injection site pain, fatigue and fever were the most common symptoms, and significantly higher antibody levels (average 19,387 AU/mL) were found in participants who had fever compared to those who did not experience fever (average antibody levels of 9,977 AU/mL, p < 0.001). This finding corresponds to previous observations of higher anti-SARS-CoV-2 IgG antibody levels in COVID-19 patients presented with fever.

ObjectiveTo assess neonatal SARS-CoV-2 anti-spike IgG antibody levels after maternal mRNA COVID-19 vaccination and/or infection during pregnancy and evaluate their protective effect.MethodsProspective observational study, conducted from January 2021 to December 2022. Infants were tested for anti-spike IgG antibodies at birth and then every 3 months until disappearance of titer. A follow-up was done for SARS-CoV-2 infection up to 12 months.ResultsIn total, 147 newborns were enrolled with a median (IQR) gestational age of 39.60 weeks (38.3–40.4). Median (IQR) titers in UA/ml at 2 days were higher (P < .001) in newborns of vaccinated 7063.7 (2841.4–14,448.1), than of infected mothers 372.7 (158.00–884.90). Titers dropped significantly during the follow-up but 50% still had a detectable titer at 6 months. A high antibody titer at 2 days led to a longer persistence (HR 0.89, IC 95% 0.83–0.96, P = .004). In total, 36 infants were infected during the first months of life coinciding with the Omicron variant. Fifty percent had detectable antibodies during the infection period. Relationship between high IgG titers and month of infection was inverse (RHO − 0.52, P = .009).ConclusionThough a high antibody titer at birth led to longer persistence, no protective effect against infection was found. As newborns are a high risk group for COVID-19, avoiding transmission during the first year of life is important.

Mass vaccination against the disease caused by the novel coronavirus (COVID-19) was a crucial step in slowing the spread of SARS-CoV-2 in 2021. Even in the face of new variants, it still remains extremely important for reducing hospitalizations and COVID-19 deaths. In order to better understand the short- and long-term dynamics of humoral immune response, we present a longitudinal analysis of post-vaccination IgG levels in a cohort of 166 Romanian healthcare workers vaccinated with BNT162b2 with weekly follow-up until 35 days past the first dose and monthly follow-up up to 6 months post-vaccination. A subset of the patients continued with follow-up after 6 months and either received a booster dose or got infected during the Delta wave in Romania. Tests were carried out on 1694 samples using a CE-marked IgG ELISA assay developed in-house, containing S1 and N antigens of the wild type virus. Participants infected with SARS-CoV-2 before vaccination mount a quick immune response, reaching peak IgG levels two weeks after the first dose, while IgG levels of previously uninfected participants mount gradually, increasing abruptly after the second dose. Overall higher IgG levels are maintained for the previously infected group throughout the six month primary observation period (e.g. 36–65 days after the first dose, the median value in the previously infected group is 5.29 AU/ml, versus 3.58 AU/ml in the infection naïve group, p less than 0.001). The decrease of IgG levels is gradual, with lower median values in the infection naïve cohort even 7–8 months after vaccination, compared to the previously infected cohort (0.7 AU/ml versus 1.29 AU/ml, p = 0.006). Administration of a booster dose yielded higher median IgG antibody levels than post second dose in the infection naïve group and comparable levels in the previously infected group.

Background After the exit “zero-COVID” strategy in mainland China by the end of 2022, a large-scale COVID-19 outbreak seeded by Omicron variants occurred. An inhaled adenovirus type-5 vector-based (i.e., inhaled Ad5-nCoV) COVID-19 vaccine was licensed earlier in 2021. In this study, we aimed to assess the real-world effectiveness of a heterologous booster of inhaled Ad5-nCoV vaccine against Omicron infection and compared with the protection from hybrid immunity (i.e., prior breakthrough infection). Methods In this retrospective cohort study, we identified 1087 out of a total of 1146 hospital staff from a tertiary hospital in Urumqi city, China from November 22 to December 29, 2022. Demographic characteristics, baseline health status, occupation, behavioral factors, laboratory test of serological IgG antibody, and timeline from immunization to laboratory-testing outcome were obtained. We analysed the individual-level vaccination status of inhaled Ad5-nCoV vaccine, prior SARS-CoV-2 infection status and baseline vaccination status, and other risk factors before follow-up. The protective effects of the heterologous inhaled Ad5-nCoV vaccine and hybrid immunity against Omicron BA.5 infection and hospitalization were calculated as relative rate reduction (RRR), which was estimated using multivariate Poisson regression models. Results A total of 1087 hospital staff (median age of 34 years, and 343 males [31.6%]), including 931 accepted for serological antibody tests, were recruited to assess the vaccine effectiveness (VE) of the inhaled Ad5-nCoV booster and hybrid immunity. Among the 1087 participants, 413 had a history of prior SARS-CoV-2 infection (before follow-up) but did not receive an inhaled Ad5-nCoV booster, and 674 reported no prior infection, including 390 who received an inhaled Ad5-nCoV booster. The highest serological IgG antibody level was detected among the inhaled Ad5-nCoV group, with a median of 294.59 S/CO, followed by the hybrid immunity group, with a median of 93.65 S/CO compared to the reference level of the inactivated vaccine group (most of whom received the Sinopharm/BBIBP-CorV vaccine). The inhaled Ad5-nCoV booster and hybrid immunity yielded RRRs of 41.9% (95% CI: 24.8, 55.0) and 97.9% (95% CI: 94.2, 99.2), respectively, against Omicron BA.5 infection, regardless of symptom status. Conclusion We found that hybrid immunity could provide a high level of protection against Omicron infection, while a heterologous inhaled Ad5-nCoV booster conferred a moderate level of protection. Our findings supported the rollout of a heterologous vaccination strategy regardless of preexisting vaccine coverage.

In Indonesia, 2.4% of all new tuberculosis patients had multi-drug resistant disease (MDR-TB); an estimated 24,000 incidences. Historical case series of MDR-TB described a high frequency of cavitation and poor prognosis. The diagnosis of chronic pulmonary aspergillosis (CPA) relies on raised levels of Aspergillus IgG antibodies, and detectable Histoplasma IgG antibodies are suspicious for chronic pulmonary histoplasmosis (CPH). We investigated whether MDR-TB patients might have concurrent CPH or CPA. This was a cross-sectional study with 50 MDR-TB patients. ELISA was used to detect Histoplasma IgG antibodies and lateral flow assay was used to detect Aspergillus IgG/IgM antibodies. Several other possible disease determinants were assessed by multivariate analysis. Of the 50 MDR-TB patients, 14 (28%) and 16 (32%) had positive Histoplasma or Aspergillus serology; six patients (12%) had dual antibody reactivity. Radiological abnormalities in positive patients included diffuse or local infiltrates, nodules, consolidation, and apical cavities, consistent with CPH and CPA. Patients with detectable fungal antibodies tended to have worse disease, and 4 of 26 (15.3%) died in the first 5 months of dual infection (p = 0.11 compared with no deaths in those with only MDR-TB). The criteria for the diagnosis of CPH and CPA were fulfilled in those with moderately and far advanced disease (13 of 14 or 93%) and 12 of 16 (75%), respectively. Damp housing was the only determinant associated with Histoplasma antibodies (PR 2.01; 95%CI 0.56–7.19), while pets were associated with the Aspergillus antibody (PR 18.024; 95%CI 1.594–203.744). CPA or CPH are probably frequent in MDR-TB patients in Indonesia and may carry a worse prognosis.