Anti-Spike IgG antibodies as correlates of protection against SARS-CoV-2 infection in the pre-Omicron and Omicron era.

Anti-Spike IgG antibodies against SARS-CoV-2, which are elicited by vaccination and infection, are correlates of protection against infection with pre-Omicron variants. Whether this association can be generalized to infections with Omicron variants is unclear. We conducted a retrospective cohort study with 8457 blood donors in Tyrol, Austria, analyzing 15,340 anti-Spike IgG antibody measurements from March 2021 to December 2022 assessed by Abbott SARS-CoV-2 IgG II chemiluminescent microparticle immunoassay. Using a Bayesian joint model, we estimated antibody trajectories and adjusted hazard ratios for incident SARS-CoV-2 infection ascertained by self-report or seroconversion of anti-Nucleocapsid antibodies. At the time of their earliest available anti-Spike IgG antibody measurement (median November 23, 2021), participants had a median age of 46.0 years (IQR 32.8-55.2), with 45.3% being female, 41.3% having a prior SARS-CoV-2 infection, and 75.5% having received at least one dose of a COVID-19 vaccine. Among 6159 participants with endpoint data, 3700 incident SARS-CoV-2 infections with predominantly Omicron sublineages were recorded over a median of 8.8 months (IQR 5.7-12.4). The age- and sex-adjusted hazard ratio for SARS-CoV-2 associated with having twice the anti-Spike IgG antibody titer was 0.875 (95% credible interval 0.868-0.881) overall, 0.842 (0.827-0.856) during 2021, and 0.884 (0.877-0.891) during 2022 (all p < 0.001). The associations were similar in females and males (Pinteraction = 0.673) and across age (Pinteraction = 0.590). Higher anti-Spike IgG antibody titers were associated with reduced risk of incident SARS-CoV-2 infection across the entire observation period. While the magnitude of association was slightly weakened in the Omicron era, anti-Spike IgG antibody continues to be a suitable correlate of protection against newer SARS-CoV-2 variants.

A high functional cure rate was induced by pegylated interferon alpha-2b treatment in postpartum hepatitis B e antigen-negative women with chronic hepatitis B virus infection: an exploratory study.

Background and aims: Limited data have been reported on achieving functional cure using pegylated interferon (Peg-IFN) alpha-2b treatment for postpartum hepatitis B e antigen (HBeAg)-negative women with chronic hepatitis B virus (HBV) infection. This study was to assess the effectiveness and safety of Peg-IFN alpha-2b in HBV postpartum women without HBeAg and identify factors linked to the functional cure. Methods: A total of 150 HBeAg-negative postpartum women were retrospectively recruited.47 patients received Peg-IFN alpha-2b [Peg-IFN(+) group] and 103 patients did not [Peg-IFN(-) group]. Propensity score matching (PSM) was used to adjust the baseline imbalance between the two groups. The patients were followed for at least 48 weeks. The primary endpoints were hepatitis B surface antigen(HBsAg) loss and HBsAg seroconversion at 48 weeks. Logistic regression analysis was used to assess factors associated with HBsAg loss at 48 weeks. Results: At week 48,the HBsAg loss and seroconversion rate in Peg-IFN(+) group were 51.06%(24/47) and 40.43%(19/47), respectively. Even after PSM, Peg-IFN(+) group still showed higher HBsAg loss rate (50.00% vs 7.14%,p<0.001) and higher HBsAg seroconversion rate (38.10% vs 2.38%,p<0.001). Baseline HBsAg levels (Odds Ratio [OR]: 0.051, 95% Confidence Interval [CI]: 0.003-0.273, P=0.010), HBsAg at week 24 (OR:0.214, 95%CI:0.033-0.616, P=0.022), HBsAg decline at week 24 (OR:4.682, 95%CI: 1.624-30.198, P=0.022) and postpartum flare (OR:21.181, 95%CI:1.872-633.801, P=0.030) were significantly associated with HBsAg loss at week 48 after Peg-IFN alpha-2b therapy. Furthermore, the receiver operating characteristic curve (ROC) showed that the use of baseline HBsAg<182 IU/mL, HBsAg at week24 < 4 IU/mL and HBsAg decline at week24>12IU/mL were good predictors of HBsAg loss. No serious adverse events were reported. Conclusion: Peg-IFN alpha-2b treatment could achieve a high rate of HBsAg loss and seroconversion in HBeAg-negative postpartum women with reliable safety, particularly for patients experience postpartum flare and have low baseline HBsAg levels.

Estimating the key outcomes and hepatocellular carcinoma risk in patients in immune-tolerant phase of chronic hepatitis B virus infection: A systematic review and meta-analysis.

The question of whether patients in the immune-tolerant (IT) phase of chronic hepatitis B virus (HBV) infection should undergo antiviral therapy and determine the optimal regimen remains unclear. A comprehensive search of PubMed, Embase, MEDLINE, Cochrane Library, and Wanfang Data from inception to 5 December 2023, was conducted. Studies reporting on key outcomes such as HBV DNA undetectability, HBeAg loss or seroconversion, HBsAg loss or seroconversion, and hepatocellular carcinoma (HCC) incidence in patients in the IT phase of chronic HBV infection were included. In total, 23 studies were incorporated. Approximately 4% of patients in the IT phase achieved spontaneous HBeAg loss over 48 weeks of follow-up. Antiviral therapy demonstrated a favourable impact on HBV DNA negative conversion (Children: risk ratios [RR] = 6.83, 95% CI: 2.90-16.05; Adults: RR = 25.84, 95% CI: 6.47-103.31) and HBsAg loss rates (Children: RR = 9.49, 95% CI: 1.74-51.76; Adults: RR = 7.35, 95% CI: 1.41-38.27) for patients in the IT phase. Subgroup analysis revealed that in adult patients in the IT phase, interferon plus nucleos(t)ide analogues (NA)-treated patients exhibited a higher pooled rate of HBsAg loss or seroconversion than those treated with NA monotherapy (9% vs. 0%). Additionally, the pooled annual HCC incidence for patients in the IT phase was 3.03 cases per 1000 person-years (95% CI: 0.99-5.88). Adult patients in the IT phase had a significantly lower HCC incidence risk than HBeAg-positive indeterminate phase patients (RR = 0.46, 95% CI: 0.32-0.66), with no significant differences observed between IT and immune-active phases. Presently, there is insufficient evidence solely based on reducing the risk of HCC incidence, to recommend treating patients in the IT phase of chronic HBV infection. However, both adult and paediatric patients in the IT phase responded well to antiviral therapy, showing favourable rates of HBsAg loss or seroconversion.

Hydroxychloroquine is associated with lower seroconversion upon 17DD-Yellow fever primovaccination in patients with primary Sjögren's syndrome.

The present study aimed at investigating whether the hydroxychloroquine (HCQ) treatment would impact the neutralizing antibody production, viremia levels and the kinetics of serum soluble mediators upon planned 17DD-Yellow Fever (YF) primovaccination (Bio-Manguinhos-FIOCRUZ) of primary Sjögren's syndrome (pSS). A total of 34 pSS patients and 23 healthy controls (HC) were enrolled. The pSS group was further categorized according to the use of HCQ (HCQ and Non-HCQ). The YF-plaque reduction neutralization test (PRNT ≥1:50), YF viremia (RNAnemia) and serum biomarkers analyses were performed at baseline and subsequent time-points (Day0/Day3-4/Day5-6/Day7/Day14-D28). The pSS group showed PRNT titers and seropositivity rates similar to those observed for HC (GeoMean = 238 vs 440, p = .11; 82% vs 96%, p = .13). However, the HCQ subgroup exhibited lower seroconversion rates as compared to HC (GeoMean = 161 vs 440, p = .04; 69% vs 96%, p = .02) and Non-HQC (GeoMean = 161 vs 337, p = .582; 69% vs 94%, p = .049). No differences in YF viremia were observed amongst subgroups. Serum biomarkers analyses demonstrated that HCQ subgroup exhibited increased levels of CCL2, CXL10, IL-6, IFN-γ, IL1-Ra, IL-9, IL-10, and IL-2 at baseline and displayed a consistent increase of several biomarkers along the kinetics timeline up to D14-28. These results indicated that HCQ subgroup exhibited a deficiency in assembling YF-specific immune response elicited by 17DD-YF primovaccination as compared to Non-HCQ subgroup. Our findings suggested that hydroxychloroquine is associated with a decrease in the humoral immune response after 17DD-YF primovaccination.

The seroconversion history to SARS-CoV-2 in Indigenous people from Brazil - the interplay between exposure, vaccination, and tuberculosis.

The COVID-19 pandemic caused a significant loss of human lives and a worldwide decline in quality of life. Although our understanding of the pandemic has improved significantly since the beginning, the natural history of COVID-19 and its impacts on under-represented populations, such as Indigenous people from America, remain largely unknown. We performed a retrospective serological survey with two Brazilian Indigenous populations (n=624), Tupiniquim and Guarani-Mbyá. Samples were collected between September 2020 and July 2021: a period comprising the dissemination of SARS-CoV-2 variants and the beginning of COVID-19 vaccination in Brazil. Seroconversions against S and N antigens were assessed using three different commercially available ELISA kits. Samples were also used to assess the prevalence of tuberculosis (TB) in the same population (n=529). Seroconversion against SARS-CoV-2 antigens was considered positive if at least one of the three ELISA kits detected levels of specific antibodies above the threshold specified by the manufacturer. In this sense, we report 56.0% (n=349/623) of seroconverted individuals. Relative seroconversion peaked after introduction of the Coronavac vaccine in February 2021. Vaccination increased the production of anti-S IgG from 3.9% to 48.6%. Our results also indicated that 11.0% (n=46/417) of all individuals were positive for TB. Seroconversion to SARS-CoV-2 was similar between individuals with positive tuberculosis test results to those with negative test results. Most vaccinated individuals seroconverted to SARS-CoV-2, indicating that Coronavac may be as protective in individuals from these indigenous groups as observed in the general Brazilian population. COVID-19 severity was minimal regardless of incomplete vaccine coverage, suggesting that vaccination may not be the only factor protecting individuals from severe COVID-19. Tuberculosis is highly prevalent and not associated with increased seroconversion to SARS-CoV-2.

Autoantibody-positivity before and seroconversion during treatment with anti-PD-1 is associated with immune-related adverse events in patients with melanoma.

INTRODUCTION: Treatment with the immune checkpoint inhibitor anti-programmed cell death protein-1 (PD-1) often causes immune-related adverse events (irAEs). Since irAEs resemble autoimmune diseases, autoantibodies might play a role and could potentially be used to identify patients at risk. Therefore, we investigated the association between autoantibody-positivity and toxicity as well as clinical response in patients with melanoma treated with anti-PD-1. MATERIALS AND METHODS: This two-center, retrospective study included 143 patients with melanoma treated with anti-PD-1. Toxicities grade ≥2 and recurrences/responses were captured until 6 months after treatment initiation. Autoantibody measurements were performed at baseline and 3 months after treatment initiation, including IgM-rheumatoid factor (RF), antinuclear antibodies (ANA), extractable nuclear antigen, anti-cyclic citrullinated peptide antibodies (anti-CCP2) and anti-thyroid antibodies. RESULTS: 169 irAEs were experienced by 86/143 patients (137 grades 1-2, 32 grades 3-4), the most common being thyroiditis (n=25), dermatitis (n=24), and sicca problems (n=19). Patients with autoantibodies at baseline experienced more irAEs (p=0.001), predominantly associated with anti-thyroid antibodies and thyroid dysfunction. No association was observed between any irAE and anti-CCP2, RF or ANA. In women, baseline and on-treatment anti-thyroid antibody-positivity as well as seroconversion during treatment was associated with thyroid dysfunction. In men, this association was only observed on-treatment. The presence of autoantibodies was not associated with melanoma recurrence (p=0.776) or response (p=0.597). CONCLUSION: The presence of autoantibodies prior to anti-PD-1 therapy is associated with irAEs in patients with melanoma. Both baseline positivity and seroconversion of anti-thyroid antibodies were strongly associated with thyroid dysfunction. This association was stronger in women, with all women who were baseline positive developing thyroid dysfunction.

A longitudinal study on SARS-CoV-2 seroconversion, reinfection and neutralisation spanning several variant waves and vaccination campaigns, Heinsberg, Germany, April 2020 to November 2022.

BackgroundSince its emergence in December 2019, over 700 million people worldwide have been infected with SARS-CoV-2 up to May 2024. While early rollout of mRNA vaccines against COVID-19 has saved many lives, there was increasing immune escape of new virus variants. Longitudinal monitoring of population-wide SARS-CoV-2 antibody responses from regular sample collection irrespective of symptoms provides representative data on infection and seroconversion/seroreversion rates.AimTo examine adaptive and cellular immune responses of a German SARS-CoV-2 outbreak cohort through several waves of infection with different virus variants.MethodsUtilising a 31-month longitudinal seroepidemiological study (n = 1,446; mean age: 50 years, range: 2-103) initiated during the first SARS-CoV-2 superspreading event (February 2020) in Heinsberg, Germany, we analysed acute infection, seroconversion and virus neutralisation at five follow-up visits between October 2020 and November 2022; cellular and cross-protective immunity against SARS-CoV-2 Omicron variants were also examined.ResultsSARS-CoV-2 spike (S)-specific IgAs decreased shortly after infection, while IgGs remained stable. Both increased significantly after vaccination. We predict an 18-month half-life of S IgGs upon infection. Nucleocapsid (N)-specific responses declined over 12 months post-infection but increased (p < 0.0001) during Omicron. Frequencies of SARS-CoV-2-specific TNF-alpha+/IFN-gamma+ CD4+ T-cells declined over 12 months after infection (p < 0.01). SARS-CoV-2 S antibodies and neutralisation titres were highest in triple-vaccinated participants infected between April 2021 and November 2022 compared with infections between April 2020 and January 2021. Cross neutralisation against Omicron BQ.1.18 and XBB.1.5 was very low in all groups.ConclusionInfection and/or vaccination did not provide the population with cross-protection against Omicron variants.

Network-based strategies to combat HCV: Examining social and spatial drivers of transmission among PWID in New Delhi.

People who inject drugs (PWID) account for some of the fastest-growing HCV epidemics globally. While individual risk factors for infection are understood, less is known about network and spatial factors critical for elimination strategies. Two thousand five hundred twelve PWID in New Delhi, India, were recruited (2017-19) through network referrals. Biometrics identified duplicates and cross-network linkages. Participants completed semi-annual surveys and blood tests for HCV antibodies and RNA. Poisson regression and network analyses identified predictors of incident HCV and compared network-based intervention approaches. Baseline HCV antibody prevalence was 65.1%, of whom 79.6% were HCV RNA-positive. We observed 92 HCV seroconversions over 382.25 person-years (incidence: 24.1 per 100 person-years). Of the 92 seroconverters, 67% (62) were directly connected to an RNA-positive participant, and all were within one degree of separation from an RNA-positive participant. Individual-level factors associated with seroconversion included age, sexual activity, and injection behaviours. After adjusting for individual-level factors, seroconversion was significantly associated with number of RNA-positive partners (adjusted incidence rate ratio [AIRR] = 1.30) and injecting at a particular venue (AIRR = 2.53). This association extended to indirect ties, with 17% reduced odds of seroconversion for each degree of separation from the venue (AIRR = 0.83). Network analyses comparing intervention strategies found that targeting venues identified more cases compared to a treat-a-friend approach. We observed a fast-growing HCV epidemic driven by viremia within individuals' immediate networks and indirect social and spatial ties, demonstrating the importance of achieving broad, sustained virologic response and rethinking network-based interventions to include venues.

Factors associated with PrEP-era HIV seroconversion in a 4-year U.S. national cohort of n = 6059 sexual and gender minority individuals who have sex with men, 2017-2022.

INTRODUCTION: Community-based cohort studies of HIV seroconversion can identify important avenues for enhancing HIV prevention efforts in the era of pre-exposure prophylaxis (PrEP). Within individuals, one can assess exposure and outcome variables repeatedly and with increased certainty regarding temporal ordering. This cohort study examined the association of several risk factors with subsequent HIV seroconversion. METHODS: We report data from a 4-year study (2017-2022) of 6059 HIV seronegative sexual and gender minority individuals who have sex with men who had indications for-, but were not using-, PrEP at enrolment. Participants completed repeat exposure assessments and self-collection of biospecimens for HIV testing. We examined the roles of race and ethnicity, socio-economic status, methamphetamine use and PrEP uptake over the course of follow-up in relation to HIV seroconversion. RESULTS: Over 4 years, 303 of the participants seroconverted across 18,421 person-years (incidence rate = 1.64 [95% CI: 1.59-1.70] per 100 person-years). In multivariable discrete-time survival analysis, factors independently associated with elevated HIV seroconversion risk included being Black/African American (adjusted risk ratio [aRR]: 2.44, 1.79-3.28), Hispanic/Latinx (1.53, 1.19-1.96), housing instability (1.58, 1.22-2.05) and past year methamphetamine use (3.82, 2.74-5.33). Conversely, time since study enrolment (24 vs. 12 months, 0.67, 0.51-0.87; 36 months, 0.60, 0.45-0.80; 48 months, 0.48, 0.35-0.66) and higher education (master's degree or higher vs. less than or equal to high school, 0.36, 0.17-0.66) were associated with reduced seroconversion risk. Compared to non-PrEP users in the past 2 years without a current clinical indication, those who started PrEP but then discontinued had higher seroconversion risk, irrespective of clinical indication (3.23, 1.74-6.46) or lack thereof (4.30, 1.85-9.88). However, those who initiated PrEP in the past year (0.14, 0.04-0.39) or persistently used PrEP in the past 2 years (0.33, 0.14-0.74) had a lower risk of seroconversion. Of all HIV seroconversions observed during follow-up assessments (12, 24, 36 and 48 months), methamphetamine was reported in the 12 months prior 128 (42.2%) times (overall). CONCLUSIONS: Interventions that acknowledge race and ethnicity, economic variables such as education and housing instability, and methamphetamine use are critically needed. Not only are interventions to engage individuals in PrEP care needed, but those that retain them, and re-engage those who may fall out of care are essential, given the exceptionally high risk of seroconversion in these groups.

Predictive role of early treatment dynamics of HBV RNA and HBcrAg for HBeAg seroconversion in children with chronic hepatitis B.

This study aimed to assess the predictive capacity of emerging serological markers, serum HBV RNA and HBcrAg, for HBeAg seroconversion in children with HBeAg-positive chronic hepatitis B (CHB). Treatment-naïve HBeAg-positive CHB children who admitted to the Liver Disease Center of Hunan Children's Hospital between April 2021 and September 2022 and received treatment with the combined entecavir and interferon-alpha treatment were recruited. Serum HBV RNA and HBcrAg were measured at baseline and Weeks 12, 24, and 48 of treatment. Our study showed that serum HBV RNA (HR = 0.71, 95% CI: 0.56-0.91, p = 0.006), HBcrAg (HR = 0.60, 95% CI: 0.43-0.84, p = 0.003), and HBsAg (HR = 0.49, 95%CI: 0.36-0.69, p < 0.001) at Week 12 were independent predictors of HBeAg seroconversion. ROC curve analysis presented that serum HBV RNA decline value (ΔHBV RNA) at Week 36 and HBcrAg decline value (ΔHBcrAg) at Week 12 (AUC = 0.871, p = 0.003 and AUC = 0.810, p = 0.003, respectively) could effectively predict HBeAg seroconversion. Furthermore, the optimal critical values were determined and the children with ΔHBV RNA > 3.759 log10 copies/mL at Week 36 or ΔHBcrAg >0.350 log10 U/mL at Week 12 more likely to achieve HBeAg seroconversion. The serum HBV RNA and HBcrAg provide new insights into the treatment of CHB in children. Early assessment of serum HBV RNA and HBcrAg during treatment can assist clinical decision-making and optimize individualized therapeutic approaches.

18-month longitudinal SARS COV-2 neutralizing antibody dynamics in haemodialysis patients receiving heterologous 3-dose vaccination (AZD-1222- AZD-1222- BNT162b2) in a lower middle income setting.

BACKGROUND: Patients with chronic kidney disease on haemodialysis (HD) were given priority COVID-19 vaccination due to increased disease risk. The immune response to COVID-19 vaccination in patients on HD was diminished compared to healthy individuals in 2-dose studies. This study aimed to evaluate seroconversion rate, neutralizing antibody (nAB) levels and longitudinal antibody dynamics to 3-dose heterologous vaccination against COVID-19 in a cohort of HD patients compared to healthy controls and assess patient factors associated with antibody levels. METHODS: This study was a case-control longitudinal evaluation of nAB dynamics in 74 HD patients compared to 37 healthy controls in a low/middle income setting. Corresponding samples were obtained from the two cohorts at time-points (TP) 1-1-month post 2nd dose of AZD1222 vaccine, TP2- 4 months post 2nd dose, TP4- 2 weeks post 3rd dose with BNT162b2 vaccine, TP5-5 months post 3rd dose and TP6-12 months post 3rd dose. Additional data is available at TP0- pre 2nd dose and TP3- 6 months post 2nd dose in HC and HD cohorts respectively. Anti-SARS-CoV-2 nAB were detected using Genscript cPassTM pseudoviral neutralization kit. Demographic and clinical details were obtained using an interviewer administered questionnaire. RESULTS: Cohorts were gender matched while mean age of the HD cohort was 54.1yrs (vs HCs mean age, 42.6yrs, p < 0.05). Percentage seroconverted and mean/median antibody level (MAB) in the HD cohort vs HCs at each sampling point were, TP1-83.7% vs 100% (p < 0.05), MAB-450 IU/ml vs 1940 IU/ml (p < 0.0001); TP2-71.4% vs 100%, (p < 0.001), MAB- 235 IU/ml vs 453 IU/ml, (p < 0.05); TP4-95.2% vs 100% (p > 0.05), MAB-1029 IU/ml vs 1538 IU/ml (p < 0.0001); TP5-100% vs 100%, MAB-1542 IU/ml vs 1741IU/ml (p > 0.05); TP6-100% vs 100%, MAB-1961 IU/ml vs 2911 IU/ml (p > 0.05). At TP2, patients aged < 60 years (p < 0.001) were associated with maintaining seropositivity compared to patients > 60 years. CONCLUSION: Two dose vaccination of haemodialysis patients provided poor nAB levels which improved markedly following 3rd dose vaccination, the effect of which was long- lasting with high nAB levels in both patients and controls detectable at 1 year follow-up.

Association of HBeAg decline rate from mid-pregnancy to delivery with HBeAg seroconversion after delivery in hepatitis B virus-infected mothers.

There is still controversy about whether to continue antiviral therapy (AVT) after delivery, especially for pregnant women in the immune tolerance (IT) phase. In this study, a retrospective cohort study was conducted to explore the relationship between hepatitis B e antigen (HBeAg) decline rate (%) from mid-pregnancy to delivery and HBeAg seroconversion postpartum among patients using nucleos(t)ide analogs (NAs) to prevent mother-to-child transmission (MTCT), with the goal of identifying the ideal candidates for postpartum AVT continuation. This retrospective cohort study included 151 postpartum women. Univariate and multivariable logistic regression analyses were conducted to assess the association between the HBeAg decline rate (%) from mid-pregnancy to delivery and HBeAg seroconversion postpartum. Receiver operating characteristic (ROC) analysis was utilized to evaluate the predictive capacity of the HBeAg decline rate (%) and determine the optimal cut-off point. The univariate analysis revealed a significant association between the HBeAg decline rate (%) and HBeAg seroconversion postpartum (OR 1.068, 95% CI: 1.034-1.103, p < .001). In the multivariate regression analysis, adjusting for age, hepatitis B surface antigen (HBsAg) titre (log10 IU/mL) at mid-pregnancy, HBeAg titre (log10 S/CO) at mid-pregnancy, and hepatitis B virus (HBV) DNA load decline rate (%) from mid-pregnancy to delivery, the HBeAg decline rate(%) remained significantly associated with HBeAg seroconversion postpartum (OR 1.050, 95% CI: 1.015-1.093, p = .009). Then HBeAg decline rate (%) was treated as a categorical variable (tertiles) for sensitivity analysis. In the three distinct models, taking Tertile1 as a reference, women in Tertile3 still had a 4.201-fold (OR 4.201, 95% CI: 1.382-12.773, p = .011) higher risk of developing HBeAg seroconversion (p for trend <.05) after adjusting above covariates. The area under the curve (AUC) was 0.723 (95% CI: 0.627-0.819). The optimal cut-off value was 5.43%, with a sensitivity of 0.561, specificity of 0.791, and Youden's index of 0.352.A higher HBeAg decline rate (%) from mid-pregnancy to delivery independently correlated with an increased risk of HBeAg seroconversion postpartum. This decline rate can serve as a valuable clinical indicator for predicting HBeAg seroconversion.

Immune response of COVID-19 vaccines in solid cancer patients: A meta-analysis.

Solid cancer patients, compared to their healthy counterparts, are at a greater risk of contracting and suffering from severe complications and poorer prognosis after COVID-19 infections. They also have different immune responses after doses of COVID-19 vaccination, but limited evidence is available to reveal the effectiveness and help to guide immunization programs for this subpopulation; MEDLINE, Embase, Web of Science, Cochrane Library databases, and clinicaltrials.gov were used to search literature. The pooled seroconversion rate was calculated using a random-effects model and reported with a 95% confidence interval (CI); The review includes 66 studies containing serological responses after COVID-19 vaccination in 13,050 solid cancer patients and 8550 healthy controls. The pooled seropositive rates after the first dose in patients with solid cancer and healthy controls are 55.2% (95% CI 45.9%-64.5% N = 18) and 90.2% (95% CI 80.9%-96.6% N = 13), respectively. The seropositive rates after the second dose in patients with solid cancer and healthy controls are 87.6% (95% CI 84.1%-90.7% N = 50) and 98.9% (95% CI 97.6%-99.7% N = 35), respectively. The seropositive rates after the third dose in patients with solid cancer and healthy controls are 91.4% (95% CI 85.4%-95.9% N = 21) and 99.8% (95% CI 98.1%-100.0% N = 4), respectively. Subgroup analysis finds that study sample size, timing of antibody testing, and vaccine type have influence on the results; Seroconversion rates after COVID-19 vaccination are significantly lower in patients with solid malignancies, especially after the first dose, then shrinking gradually after the following two vaccinations, indicating that subsequent doses or a booster dose should be considered for the effectiveness of this subpopulation.

Outcomes of Kidneys Transplanted From Hepatitis C Viremic Donors to Naive Recipients From an Appalachian Rural Kidney Transplant Program.

OBJECTIVES: Before the advent of direct-acting antiviral therapy for hepatitis C virus, a large proportion of kidneys from donors with hepatitis C viremia were discarded. Hepatitis C virus is now amenable to effective treatment with excellent seronegativity rates. In this study, we review the outcomes of hepatitis C viremic kidneys transplanted into hepatitis C-naive recipients. MATERIALS AND METHODS: In this retrospective observational study, we examined 6 deceased donor kidneys with hepatitis C viremia that were transplanted into hepatitis C-naive recipients between March 2020 and April 2021 at a single center. Because of health insurance constraints, patients were treated for hepatitis C virus with glecaprevir/pibrentasvir for 8 weeks following seroconversion posttransplant. Primary outcome measured was viral seroconversion; secondary outcomes included graft function, posttransplant complications, and all-cause mortality. RESULTS: On average, patients seroconverted 6 days (range, 4-10 d) after transplant and began treatment 26 days (range, 15-37 d) after seroconversion. An 8-week course of antiviral treatment was successful in preventing acute hepatitis C virus infection in all patients. Posttransplant median creatinine was 1.96 mg/dL (range, 1-4.55 mg/dL), whereas median estimated glomerular filtration rate was 41.33 mL/min/1.73 m2 (range, 17-85 mL/min/1.73 m2). Patient survival rate was 66.7%, and death-censored graft survival rate was 100%. Two patients died from unrelated reasons: 1 from acute respiratory failure secondary to SARS-CoV-2 infection and 1 from posttransplant lymphoproliferative disorder. Two patients developed allograft rejection posttransplant (1 developed antibody mediated rejection, 1 developed borderline T-cell-mediated cellular rejection). Other major complications included neutropenia, fungal rash, SARS-CoV-2 infection, cytomegalovirus, BK virus, and Epstein-Barr virus reactivation. CONCLUSIONS: Use of hepatitis C-viremic donor kidneys for transplant is a safe option and has great potential to increase the kidney donor pool, as long as high index of suspicion is maintained for allograft rejection and opportunistic infections.

Exposure dynamics of Ross River virus in horses - Horses as potential sentinels (a One Health approach).

Ross River virus (RRV), the most medically and economically important arbovirus in Australia, has been the most prevalent arbovirus infections in humans for many years. Infected humans and horses often suffer similar clinical symptoms. We conducted a prospective longitudinal study over a 3.5-year period to investigate the exposure dynamics of RRV in three foal cohorts (n = 32) born in a subtropical region of South East Queensland, Australia, between 2020 and 2022. RRV-specific seroconversion was detected in 56% (n = 18) of foals with a median time to seroconversion, after waning of maternal antibodies, of 429 days (95% CI: 294-582). The median age at seroconversion was 69 weeks (95% CI: 53-57). Seroconversion events were only detected between December and March (Southern Hemisphere summer) over the entire study period. Cox proportion hazards regression analyses revealed that seroconversions were significantly (p < 0.05) associated with air temperature in the month of seroconversion. Time-lags in meteorological variables were not significantly (p > 0.05) associated with seroconversion, except for relative humidity (p = 0.036 at 2-month time-lag). This is in contrast to research results of RRV infection in humans, which peaked between March and May (Autumn) and with a 0-3 month time-lag for various meteorological risk factors. Therefore, horses may be suitable sentinels for monitoring active arbovirus circulation and could be used for early arbovirus outbreak detection in human populations.

A prospective observational cohort study of covid-19 epidemiology and vaccine seroconversion in South Western Sydney, Australia, during the 2021-2022 pandemic period.

BACKGROUND: It is known that COVID-19 disproportionally adversely affects the immunocompromised, including kidney transplant recipients (KTR), as compared to the general population. Risk factors for adverse outcomes and vaccine seroconversion patterns are not fully understood. Australia was uniquely positioned to reduce initial case numbers during the 2021-2022 pandemic period due to its relative isolation and several significant public health interventions. South-Western Sydney Local Heath District was one of the predominant regions affected. METHODS: A single centre, prospective cohort study of prevalent renal transplant recipients was conducted between 25th July 2021 and 1st May 2022. Baseline characteristics, COVID-19 vaccination status, COVID-19 diagnosis and outcomes were determined from the electronic medical record, Australian vaccination register and Australian and New Zealand Dialysis and Transplant Registry. Assessment of vaccine-induced seroconversion was assessed with ELISA in a subpopulation. Analysis was performed using SPSS v.28. RESULTS: We identified 444 prevalent transplant recipients (60% male, 50% diabetic, median age 58 years (Interquartile range (IQR)21.0) and eGFR 56 ml/min/1.73m2 (IQR 21.9). COVID-19 was identified in 32% (n = 142) of patients, of which 38% (n = 54) required hospitalisation and 7% (n = 10) died. At least one COVID-19 vaccination was received by 95% (n = 423) with 17 (4%) patients remaining unvaccinated throughout the study period. Seroconversion after 2 and 3 doses of vaccine was 22% and 48% respectively. Increased COVID-19 related deaths were associated with older age (aOR 1.1, 95% CI 1.004-1.192, p = 0.040), smoking exposure (aOR 8.2, 05% CI 1.020-65.649, p = 0.048) and respiratory disease (aOR 14.2, 95%CI:1.825-110.930, p = 0.011) on multi-variable regression analysis. Receipt of three doses of vaccination was protective against acquiring COVID-19 (aOR 0.48, 95% CI 0.287-0.796, p = 0.005) and death (aOR 0.6, 95% CI: 0.007-0.523, p = 0.011), but not against hospitalisation (p = 0.32). Seroconversion was protective for acquiring COVID-19 on multi-variable regression independent of vaccination dose (aOR 0.1, 95%CI: 0.0025-0.523, p = 0.011). CONCLUSIONS: COVID-19 was associated with a high mortality rate. Older age, respiratory disease and prior smoking exposure may be risk factors for increased mortality. Vaccination of 3 doses is protective against acquiring COVID-19 and death, however not hospitalisation. Antibody response is protective for acquiring COVID-19, however seroconversion rates are low.

In the fight against HIV/AIDS: the arduous implementation of government-funded pre-exposure prophylaxis programme in Taiwan.

INTRODUCTION: The government-funded pre-exposure prophylaxis (PrEP) programme was targeted to those aged under 30 years or serodiscordant couples and implemented in September 2018-October 2020 in Taiwan. The study aimed to examine the effectiveness of the programme and the relationship between sexually transmitted disease (STD) and HIV seroconversion. METHODS: This study was a retrospective cohort analysis with questionnaires designed for participants who joined the aforementioned programme in the PrEP-designated hospitals. The questionnaires included sociodemographic factors, sexual risk behaviours, number and types of sexual partners, and usage of narcotics filled in at the beginning of the programme and every 3 months. The McNemar test was used for the paired questionnaire analysis. The HIV seroconversion status among STD-notified patients nationwide was confirmed by using the data linkage method, followed up until October 2021 with stratification of PrEP programme participation or not. RESULTS: The programme recruited 2155 people. 11 participants (0.5%) had seroconversion within the programme, while 26 (1.2%) had seroconversion after withdrawing from the programme. Overall, 1892 subjects with repeated questionnaires were included in the analysis for behaviour changes with median follow-up of 289 days. After joining the programme, 94.7% of them claimed that they had sexual behaviours: the rate of those who had condomless sex rose to 5.5% (p<0.001) and the rate of those who used narcotics decreased to 2% (p<0.001), compared with their response in the pre-questionnaire. Notably, the frequency of non-use of narcotics in recent 3 months increased from 16.9% to 38.4% in the pre-questionnaire and post-questionnaire responses, among the 177 who had claimed narcotics usage in recent 12 months (p=0.003). More HIV seroconversion was found among patients with STD who did not join the programme than those who joined the programme (8.7% vs 4.9%, p=0.031). CONCLUSIONS: The government-funded programme showed HIV case reduction and positive changes in health behaviours except for condomless sex which had increased prevalence. The reduction of HIV cases was also observed among people with STD. More resources should be allocated to the PrEP programme.

Antiviral therapy response in patients with chronic hepatitis B and fatty liver: A systematic review and meta-analysis.

The impact of concurrent fatty liver (FL) on response to antiviral therapy in chronic hepatitis B (CHB) patients has not been well characterized. We aimed to systematically review and analyse antiviral treatment response in CHB patients with and without FL. We searched PubMed, Embase, Web of Science and the Cochrane Library databases from inception to 31 May 2023 for relevant studies. Biochemical response (BR), complete viral suppression (CVS) and hepatitis B e antigen (HBeAg) seroconversion in CHB patients with FL (CHB-FL) and without FL (non-FL CHB) were compared. In an initial pool of 2101 citations, a total of 10 studies involving 2108 patients were included. After 12 weeks of treatment, CHB-FL patients as compared with non-FL CHB patients had lower BR rate (48.37% [108/227] vs. 72.98% [126/174], p = .04) but similar trend for CVS (36.86% [80/227] vs. 68.81% [114/174], p = .05) and similar rates of HBeAg seroconversion (6.59% [7/103] vs. 7.40% [7/110], p = .89). However, at week 48, there were no statistically significant differences between CHB-FL and non-FL CHB patients in any of the outcomes, including BR (60.03% [213/471] vs. 69.37% [314/717], p = .67), CVS (65.63% [459/746] vs. 73.81% [743/1132], p = .27) and HBeAg seroconversion (10.01% [30/275] vs. 14.06% [65/453], p = .58) with similar findings for week 96. BR rate was lower in CHB-FL patients after 12 weeks of antiviral treatment. However, after a longer follow-up of either 48 or 96 weeks, no statistically significant differences were observed in BR, CVS or HBeAg seroconversion rates between CHB patients with and without FL.

Low-dose dengue virus 3 human challenge model: a phase 1 open-label study.

Dengue human infection models present an opportunity to explore the potential of a vaccine, anti-viral or immuno-compound for clinical benefit in a controlled setting. Here we report the outcome of a phase 1 open-label assessment of a low-dose dengue virus 3 (DENV-3) challenge model (NCT04298138), in which nine participants received a subcutaneous inoculation with 0.5 ml of a 1.4 × 103 plaque-forming unit per ml suspension of the attenuated DENV-3 strain CH53489. The primary and secondary endpoints of the study were to assess the safety of this DENV-3 strain in healthy flavivirus-seronegative individuals. All participants developed RNAaemia within 7 days after inoculation with peak titre ranging from 3.13 × 104 to 7.02 × 108 genome equivalents per ml. Solicited symptoms such as fever and rash, clinical laboratory abnormalities such as lymphopenia and thrombocytopenia, and self-reported symptoms such as myalgia were consistent with mild-to-moderate dengue in all volunteers. DENV-3-specific seroconversion and memory T cell responses were observed within 14 days after inoculation as assessed by enzyme-linked immunosorbent assay and interferon-gamma-based enzyme-linked immunospot. RNA sequencing and serum cytokine analysis revealed anti-viral responses that overlapped with the period of viraemia. The magnitude and frequency of clinical and immunologic endpoints correlated with an individual's peak viral titre.