Effectiveness of Booster Dose of Anti SARS-CoV-2 BNT162b2 in Cirrhosis: Longitudinal Evaluation of Humoral and Cellular Response.

Background: LC has been associated with hyporesponsiveness to several vaccines. Nonetheless, no data on complete serological and B- and T-cell immune response are currently available. Aims: To assess, in comparison with healthy controls of the same age and gender, both humoral and cellular immunoresponses of patients with LC after two or three doses of the mRNA Pfizer-BioNTech vaccine against SARS-CoV-2 and to investigate clinical features associated with non-response. Material and methods: 179 patients with LC of CTP class A in 93.3% and viral etiology in 70.1% of cases were longitudinally evaluated starting from the day before the first dose to 4 weeks after the booster dose. Their antibody responses were compared to those of healthcare workers without co-morbidities. In a subgroup of 40 patients, B- and T-cell responses were also compared to controls. Results: At d31, d90 and d180 after BNT162b2 vaccine, no detectable SARS-CoV-2 IgG response was observed in 5.9%, 3.9% and 7.2% of LC patients as compared to 0 controls (p < 0.03). A delay in B-cell and lack of prompt T-cell response compared to healthcare workers was also registered. A significant correlation between antibody titers and cellular response was observed. A MELD score > 8 was the only independent predictor of poor d31 response (p = 0.028). Conclusions: Our results suggest that cirrhotic patients have a slower and in <10% suboptimal immune response to SARS-CoV-2 vaccination. Rates of breakthrough infections were comparable between cirrhotics and controls. The booster dose was critical in inducing both humoral and cellular responses comparable to controls.

Cellular and Humoral Immune Responses and Breakthrough Infections After Two Doses of BNT162b Vaccine in Healthcare Workers (HW) 180 Days After the Second Vaccine Dose.

Background: Immunity and clinical protection induced by mRNA vaccines against SARS-CoV-2 have been shown to decline overtime. To gather information on the immunity profile deemed sufficient in protecting against hospitalization, we tested IgG levels, interferon-gamma (IFN-γ) secretion, and neutralizing antibodies 180 days (d180) after the second shot of BNT162b vaccine, in HW. Methods: A total of 392 subjects were enrolled. All received BioNTech/Pfizer from February 2020 to April 2021. The vaccine-specific humoral response was quantitatively determined by testing for IgG anti-S1 domain of SARS-CoV-spike protein. Live virus microneutralization (MN) was evaluated by an assay performing incubation of serial 2-fold dilution of human serum samples, starting from 1:10 to 1:5120, with an equal volume of Wuhan strain and Delta VOC viral solution and assessing the presence/absence of a cytopathic effect. SARS-CoV-2-spike protein-specific T-cell response was determined by a commercial IFN-γ release assay. Results: In 352 individuals, at d180, IgG levels decreased substantially but no results below the assay's positivity threshold were observed. Overall, 22 naive (8.1%) had values above the highest threshold. Among COVID-naive, the impact of age, which was observed at earlier stages, disappeared at d180, while it remained significant for 81 who had experienced a previous infection. Following the predictive model of protection by Khoury, we transformed the neutralizing titers in IU/ml and used a 54 IU/ml threshold to identify subjects with 50% protective immunity. Overall, live virus MN showed almost all subjects with previous exposure to SARS-CoV-2 neutralized the virus as compared to 33% of naive double-dosed subjects (p < 0.0001). All previously exposed subjects had strong IFN-γ secretion (>200 mIU/ml); among 271 naive, 7 (2.58%) and 17 (6.27%) subjects did not show borderline or strong secretion, respectively. Conclusions: In naive subjects, low IgG titers are relatively long-lasting. Only a third of naive subjects maintain neutralizing responses. After specific stimulation, a very limited number of naive were unable to produce IFN-γ. The results attained in the small group of subjects with breakthrough infection suggest that simultaneous neutralizing antibody titers <20, binding antibody levels/ml <200, and IFN-γ <1,000 mIU/ml in subjects older than 58 may identify at-risk groups.

Associations between Allelic Variants of the Human IgH 3' Regulatory Region 1 and the Immune Response to BNT162b2 mRNA Vaccine.

The escalation of Coronavirus disease 2019 (COVID-19) has required the development of safe and effective vaccines against the severe acute respiratory syndrome coronavirus 2-associated (SARS-CoV-2), which is the causative agent of the disease. Here, we determined the levels of antibodies, antigen-specific B cells, against a recombinant GFP-tagged SARS-CoV-2 spike (S) protein and total T and NK cell subsets in subjects up to 20 days after the injection of the BNT162b2 (Pfizer-BioNTech) vaccine using a combined approach of serological and flow cytometry analyses. In former COVID-19 patients and highly responsive individuals, a significant increase of antibody production was detected, simultaneous with an expansion of antigen-specific B cell response and the total number of NK-T cells. Additionally, through a genetic screening of a specific polymorphic region internal to the 3' regulatory region 1 (3'RR1) of human immunoglobulin constant-gene (IgH) locus, we identified different single-nucleotide polymorphic (SNP) variants associated with either highly or lowly responsive subjects. Taken together, these results suggest that favorable genetic backgrounds and immune profiles support the progression of an effective response to BNT162b2 vaccination.

Quantitative serological evaluation as a valuable tool in the COVID-19 vaccination campaign.

OBJECTIVES: After exceptional research efforts, several vaccines were developed against SARS-CoV-2 which sustains the pandemic COVID-19. The Comirnaty vaccine showed high efficacy in clinical trials and was the first to be approved for its distribution to the general population. We evaluated the immune response induced by the first vaccine dose in different sex/age groups and subjects with or without naturally present anti-SARS-CoV-2 antibodies. METHODS: As part of an Italian multicenter project (Covidiagnostix), serum samples from 4,290 health-professionals were serologically tested the day of the first vaccination dose, and 21 days later, using two different instrumentations (Siemens-Healthineers and Roche). RESULTS: In total, 97% of samples showed the presence of specific antibodies 21 days after the vaccination dose; the percentage of non-responders increased with age in both genders. Remarkably, naturally seropositive individuals showed antibody persistence up to 11 months and an exceptionally higher vaccination response compared to subjects never infected by SARS-CoV-2. CONCLUSIONS: This study highlighted the importance of the serological test i) to identify naturally SARS-CoV-2 seropositive individuals and ii) to evaluate the antibody level elicited by the first vaccination dose. Both tests, highlighted differences in the immune response, when subjects were stratified by sex and age, and between naturally seropositive and seronegative subjects. The data obtained show how serological tests could play a crucial role in the triage of the population subjected to the vaccination campaign for COVID-19. The definition of suitable instrumentation-specific thresholds is needed to correctly follow eventually acquired post-vaccination immunity in the general population.

Early Serological Response to BNT162b2 mRNA Vaccine in Healthcare Workers.

PURPOSE: Clinical significance and durability of serological response after mRNA COVID-19 vaccines is under investigation. Data on early virological response are limited. To iden-tify potential predictors of antibody durability, circulating antibody levels were longitudinally ex-plored in healthcare workers included in a follow-up program for SARS-CoV-2 infection. Meth-ods: Subjects meeting the inclusion criteria signed an informed consent. Serum samples were col-lected at baseline, before the first BNT162b2 vaccine, at days 7, 21, 31, 90, and 180 days after the first dose. Serological evaluation was performed by QuantiVac Euroimmune anti-S1 antibody as-say. Only subjects followed-up until day 90 are here considered. RESULTS: Of 340 taken into consid-eration, 265 subjects were naive, and 75 COVID-19 experienced. The former showed a progres-sive increase in their antibody levels before day 90 decline, while the latter showed antibody levels reaching a plateau at day 7 and slightly declining at day 90. All showed antibody levels higher than the assay cut-off at day 31 and 90. Among naive, 108 had an early response whose predic-tors were younger age and female gender (OR 0.94, 95% CI 0.91-0.96, p < 0.0001; and OR 2.58, 95% CI 1.48-4.51, p = 0.0009). Naive subjects experienced a day 30/90 decline in antibody levels, whereas experienced did not. Early response was an independent predictor of higher day 30/90 antibody levels decline (OR = 2.05, 95% CI 1.04-4.02; p = 0.037). CONCLUSIONS: Our results suggest that in healthcare workers early response might be inversely associated with antibody levels 90 days after BNT162b2 vaccine.

Harmonization of six quantitative SARS-CoV-2 serological assays using sera of vaccinated subjects.

BACKGROUND AND AIMS: Vaccines, to limit SARS-CoV-2 infection, were produced and reliable assays are needed for their evaluation. The WHO produced an International-Standard (WHO-IS) to facilitate the standardization/comparison of serological methods. The WHO-IS, produced in limited amount, was never tested for reproducibility. This study aims at developing a reproducible and accessible working standard (WS) to complement the WHO-IS. MATERIALS AND METHODS: Sera from vaccinated individuals were used to produce the WSs. The WHO-IS, the WSs and single serum samples (n = 48) were tested on 6 quantitative serological devices. Neutralization assays were performed for the 48 samples and compared with their antibody titers. RESULTS: The WS carry an antibody titer 20-fold higher than the WHO-IS. It was reproducible, showed both good linearity and insignificant intra- and inter-laboratory variability. However, the WSs behave differently from the WHO-IS. Analysis of the 48 samples showed that single correlation factors are not sufficient to harmonize results from different assays. Yet, all the devices predict neutralization activity based on the antibody titer. CONCLUSIONS: A reproducible and highly concentrated WS, specific for IgG against SARS-CoV-2 Spike-glycoprotein was produced. Such characteristics make it particularly suited for the harmonization of commercially available assays and the consequent evaluation of post-vaccinated individuals.

High Rates of Hidden HCV Infections among Hospitalized Patients Aged 55-85.

BACKGROUND AND AIMS: The WHO has solicited all countries to eliminate HCV by 2030. The Italian government started routine screening for HCV infection in January 2021, initially targeting subjects born between 1969 and 1989. With the aim of achieving micro-elimination, we designed a hospital-wide project focusing on inpatients born from 1935 to 1985 and conducted it in our institution. METHOD: All inpatients aged 35 to 85, admitted from 10 February 2020 to 9 February 2021 for many different diseases and conditions underwent HCV antibody (HCVAb) testing by third-generation ELISA. When positive, reflex HCV RNA testing and genotyping were performed. Clinical history, fibrosis diagnosis, laboratory data and concomitant medications were available for all. RESULTS: The HCV screening rate of inpatients was 100%. In total, 11,748 participants were enrolled, of whom 53.50% were male. The HCVAb positivity rate was 3.03%. The HCVAb rate increased with age and was higher for patients born between 1935 and 1944 (4.81%). The rate of HCV RNA positivity was 0.97%. The vast majority (80.70%) of HCV RNA-positive participants were 55 or older; in about 40% of cases, HCV RNA-positive patients were unaware of their infection. Although 16 patients died after HCV chronic infection diagnosis (two due COVID-19) or HCV treatment prescription (one due to COVID-19), 74.56% of patient HCV diagnoses were linked to HCV treatment, despite their co-morbidities. All patients older than 65 who died had an active HCV infection. CONCLUSION: The present study revealed a rate of active HCV infections among inpatients lower than what has been reported in the past in the general population; this appears to be a result of the widespread use of pangenotypic direct-acting antiviral agents (DAAs). The overall rate of active infection was lower than the rate observed in the 1935-1954 cohort. The high rate of inpatients unaware of HCV infections and the high number of deaths among subjects with an active HCV infection born from 1935 to 1954, suggest that, at least in southern Italy, targeted screening of this birth cohort may be required to reduce the number of undiagnosed cases and hidden infections.

Hepatitis C virus micro-elimination: Where do we stand?

Hepatitis C virus (HCV) elimination by 2030, using direct-acting antiviral treatments, has been promoted by the World Health Organization. This achievement is not attainable, however, particularly after the 2020 pandemic of the coronavirus disease 2019. Consequently, the more realistic objective of eliminating HCV from population segments for which targeted strategies of prevention and treatment are easily attained has been promoted in Europe, as a valid alternative. The underlying idea is that micro-elimination will ultimately lead to macro-elimination. The micro-elimination strategy may target different specific populations and at-risk groups. Different settings, including prisons and hospitals, have also been identified as micro-elimination scenarios. In addition, dedicated micro-elimination strategies have been designed that are tailored at the geographical level according to HCV epidemiology and individual country's income. The main elements of a valid and successful micro-elimination project are reliable epidemiological data and active involvement of all the stakeholders. Community involvement represents another essential component for a successful program.

Guidelines Have a Key Role in Driving HCV Elimination by Advocating for Simple HCV Care Pathways.

The availability of pangenotypic direct-acting antivirals for treatment of hepatitis C (HCV) has provided an opportunity to simplify patient pathways. Recent clinical practice guidelines have recognised the need for simplification to ensure that elimination of HCV as a public health concern remains a priority. Despite the move towards simplified treatment algorithms, there remains some complexity in the recommendations for the management of genotype 3 patients with compensated cirrhosis. In an era where additional clinical trial data are not anticipated, clinical guidance should consider experience gained in real-world settings. Although more experience is required for some pangenotypic therapeutic options, on the basis of published real-world data, there is already sufficient evidence to consider a simplified approach for genotype 3 patients with compensated cirrhosis. The coronavirus disease 2019 (COVID-19) pandemic has highlighted the need to minimise the need for complex patient pathways and clinical practice guidelines need to continue to evolve in order to ensure that patient outcomes remain optimised.

Is positivity for hepatitis C virus antibody predictive of lower risk of death in COVID-19 patients with cirrhosis?

Liver injury has been reported in coronavirus disease 2019 (COVID-19) cases but the impact of pre-existing liver damage and related etiology have not been completely elucidated. Our research interests include the potential reciprocal influence of COVID-19 and pre-existing liver damage related to hepatitis C virus (HCV) infection, in particular. To this end, we have evaluated three cohorts of patients admitted at three Italian hospitals during the coronavirus pandemic; these included 332 patients with COVID-19 and 1527 patients with HCV who were from established real-world antiviral treatment study cohorts (sofosbuvir/velpatasvir), with either liver disease (various severities; n = 1319) or cirrhosis (n = 208). Among the COVID-19 patients, 10 had cirrhosis (3%), including 7 of metabolic origin and 3 of viral origin. Mortality among the COVID-19 patients was 27.1%, with 70% of those with cirrhosis of metabolic etiology having died. Cirrhosis, older age, low white blood cell count and lymphocyte count being identified as risk predictors of death [odds ratio (OR) = 13.7, 95% confidence interval (CI): 2.59-83.01, P = 0.006; OR = 1.05, 95%CI: 1.03-1.08, P = 0.0001; OR = 1.09, 95%CI: 1.36-1.16, P = 0.001; OR = 0.61, 95%CI: 0.39-0.93, P = 0.023, respectively]. In the two cohorts of HCV patients, COVID-19 diagnosis was made in 0.07% of those with liver disease and 1% of those with cirrhosis. Thus, the prevalence of HCV antibodies among COVID-19-infected patients was comparable to that currently reported for the general population in Italy. Amongst the COVID-19 patients, pre-existing metabolic cirrhosis appears to be associated with higher mortality, while HCV antibodies may be suggestive of "protection" against COVID-19.