Decrease In Antibody Levels Research Articles

Vaccination status and hepatitis A immunity in children: insights from a large-scale study in Turkey

BackgroundHepatitis A remains a public health concern, particularly in areas with suboptimal sanitation. Introduced in Turkey's immunization schedule in 2011, the vaccine has improved immunity; however, gaps persist, especially in older, unvaccinated children. This study examines the seropositivity rates and antibody levels in children across different vaccination statuses and age groups, and to identify gaps in immunity, particularly among children those born before the introduction of the hepatitis A vaccine in Turkey.MethodsData from 9,858 patients, collected between August 2019 and March 2024, were analyzed to evaluate the immunological response to the vaccine. Patients were categorized into four groups based on vaccination status: under-vaccinated (children 6–18 months old), single-dose vaccinated (children 18–24 months old), fully vaccinated (children over 24 months old born after March 1, 2011), and unvaccinated (born before March 1, 2011, when routine hepatitis A vaccination began). Seropositivity rates and antibody levels were measured and statistically analyzed.ResultsIn this study, a total of 9,858 pediatric patients were assessed, with 1.1% under-vaccinated, 3.4% single-dose vaccinated, 60.5% fully vaccinated, and 35% unvaccinated. Seropositivity rates reached 93% in the fully vaccinated group, compared to 83% in the single-dose group and 63% in the unvaccinated group. Antibody titers were significantly higher in the fully vaccinated group, with statistically significant differences in seropositivity between this group and the unvaccinated group (p < 0.001). Additionally, a notable decrease in antibody levels was observed in the unvaccinated group as age increased (r = -0.365, p < 0.001).ConclusionThese findings underscore the critical need for targeted interventions to close vaccination gaps, especially among older, unvaccinated children who exhibit lower immunity levels. These insights are crucial for enhancing vaccination outreach and improving public health measures against hepatitis A.

Does Tobacco Smoking Affect Vaccine-Induced Immune Response? A Systematic Review and Meta-Analysis.

Background. Causing approximately 8 million deaths each year, tobacco smoking represents a significant public health concern. Evidence shows that smoking significantly impairs antibody production and immune cell activity following vaccination. Objectives. This review aims to provide a comprehensive overview of the literature regarding how smoking reduces the effectiveness of active immunization by affecting vaccine-induced immune response. Methods. This study was performed according to the PRISMA guidelines, and the protocol was registered on the PROSPERO platform (ID: CRD42024582638). PubMed, Scopus and Web of Science were consulted as bibliographic and citation databases. Studies published in Italian and English and that aimed to investigate the effects of exposure to active and passive tobacco smoking on vaccine-induced immune response were included. Results. Thirty-four studies were selected. Overall, a decrease in antibody levels and avidity and in immune cell production were observed in individuals exposed to smoke. The meta-analysis showed a weighted mean difference between smokers and non-smokers equal to 0.65 (95% CI: 0.10-1.19, p = 0.02) for vaccinations against COVID-19, influenza, pneumococcus, HBV, HPV, tetanus, pertussis, polio, haemophilus influenzae type b, measles-mumps-rubella, and recurrent urinary tract infections. Conclusions. Smoking cessation campaigns should be considered in order to increase the effectiveness of vaccination programs. Furthermore, the opportunity to adopt different vaccine dosing schemes for smokers and non-smokers, especially in acute epidemics, should be considered.

Anti Phospholipase A2 Receptor 1 Antibodies and Membranous Nephropathy Recurrence After Kidney Transplantation

Membranous nephropathy can lead to end-stage kidney disease, for which kidney transplantation is the preferred therapy. However, the disease often relapses, which can impact allograft survival. We conducted a prospective multicenter study in France involving 72 patients with membranous nephropathy who were awaiting and then underwent kidney transplantation. In addition, we established a retrospective validation cohort of 65 patients. The primary objective was to evaluate the prognostic significance of pretransplant anti phospholipase A2 receptor 1 (PLA2R1) antibodies on the recurrence of membranous nephropathy. The study also assessed the incidence rate, time to onset, and risk factors for recurrence, as well as allograft outcome. The prospective cohort showed a 26% cumulative incidence of membranous nephropathy recurrence after a median follow-up of 23.5 months. This was confirmed by a 28% cumulative incidence after a median follow-up of 67 months in the retrospective cohort. A strong association was found between the presence of anti-PLA2R1 antibodies prior to transplantation and the risk of disease recurrence (risk ratio= 5.9; 95% confidence interval [CI]: 2.3-15.7; P< 0.0001). These results were confirmed in the retrospective cohort. Monitoring of anti-PLA2R1 antibodies in the immediate posttransplant period is of limited value, because recurrence occurred early in the first 6 months (median delay of 5 [3-14] months) after transplantation despite decreasing antibody levels. The presence of anti-PLA2R1 antibodies prior to transplantation was a strong predictor of recurrence of allograft membranous nephropathy. An individualized immunomonitoring and management strategy for kidney transplant candidates with anti-PLA2R1-associated membranous nephropathy should be considered.

#1800 Cascade filtration in severe pulmonary-kidney syndrome: an one-center experience

Abstract Background and Aims In some forms of rapidly progressive glomerulonephritis (RPGN), the effect of plasma exchange (PE) is not well understood. Cascade filtration (CF) differs from standard PE in that it uses a double filter system, where the first filter is used to separate plasma from whole blood and the second filter is used to filter high-molecular weight substances. In this study, we investigated the efficacy and safety of CF in patients with ANCA-associated vasculitis (AAV) and Goodpasture's syndrome (GPS). Method During one year we included 18 patients with RPGN whose received CF in the study. The eligibility criteria was eGFR ≤15 ml/min/1.73 m2 and/or diffuse alveolar hemorrhage (DAH), presence of antineutrophilic antibodies or anti-GBM-antibodies. CF was performed on a Plasauto Sigma using a Plasmaflo OP-05W plasma separator and a Cascadeflo EC-30W separator with a fresh frozen plasma or 25% albumin solution. All patients received immunosuppressive therapy with steroids and cyclophosphamide, one patient with AAV received rituximab due to anemia and thromobocytopenia. All data were obtained from one hospitalization with the median of 43 days. Results Eight patients with AAV and three patients with GPS met the eligibility criteria. The median age of the patients in the AAV group was 59.8 (48; 66) years, with a female to male ratio of 1:1. All patients had evidence of systemic disease: seven patients had lung damage, including DAH, two patients had arthralgia, one had purpura and one had severe sinonasal involvement. The median creatinine level was 588 µmol/l (382; 1352), dialysis was initiated in 6 patients, and the median Birmingham Vasculitis Activity Score (BVAS) was 17 (15; 20). After three procedures of CF, all patients showed positive changes on CT scan, and dialysis was stopped in three patients. The immunological response to CF was observed quite rapidly in seven patients, with decreasing ANCA titer after three exchanges and decreasing antibody levels after six exchanges in one patient. There was a significant decrease in inflammatory markers, median C-reactive protein at baseline 179 (147; 226) decreased to 23 (2.8; 30.9) mg/l (p = 0.041). The CF was well tolerated with no significant adverse events. One patient receiving rituximab died after 4 months due to a severe COVID 19 infection. Three patients with GPS, one male 23 years old and two females 56 and 60 years old, also received CF. Creatinine concentrations at baseline were 1285, 1299 and 661 µmol/l, BVAS scores were 18, 20 and 15, respectively. After three procedures of CF, there was an immunological response: decrease in antibody levels from 121 U/ml to 15 U/ml, from 88.2 to 18.4 U/ml, from &amp;gt; 200.0 to 85.4 U/ml, CRP from 252 to 0.7 mg/l, from 120 to 5 mg/l, from 81.9 to 12.58 mg/l. There were no deaths and all three patients remained on dialysis. Conclusion CF was an effective and well tolerated method of treating severe AAV and GPS in addition to immunosuppressive treatment. Possibly due to the different filtration principle and the absence of donor plasma, we did not observe any infection-related adverse events and a lower number of procedures of CF was required compared to standard plasma exchanges. Further larger studies are needed to evaluate the benefits and safety of CF in combination with immunosuppressive treatment in RPGN patients.

Anti-spike antibody durability after SARS-CoV-2 vaccination in adolescent solid organ transplant recipients.

Adolescent solid organ transplant recipients (aSOTRs) who received three doses of the COVID-19 mRNA vaccine experience high seroconversion rates and antibody persistence for up to 3 months. Long-term antibody durability beyond this timeframe following three doses of the SARS-CoV-2 mRNA vaccine remains unknown. We describe antibody responses 6 months following the third vaccine dose (D3) of the BNT162b2 mRNA vaccination among aSOTRs. Participants in a multi-center, observational cohort who received the third dose of the vaccine were analyzed for antibodies to the SARS-CoV-2 spike protein receptor-binding domain (Roche Elecsys anti-SARS-CoV-2-S positive: ≥0.8, maximum: >2500 U/mL). Samples were collected at 1-, 3-, and 6-months post-D3. Participants were surveyed at each timepoint and at 12-months post-D3. All 34 participants had positive anti-RBD antibody titers 6 months post-D3. Variations in titers occurred between 3 and 6 months post-D3, with 8/28 (29%) having decreased antibody levels at 6 months compared to 3 months and 2/28 (7%) reporting increased titers at 6 months. The remaining 18/28 (64%) had unchanged antibody titers compared to 3-month post-D3 levels. A total of 4/34 (12%) reported breakthrough infection within 6 months and 3/32 (9%) reported infection after 6-12 months following the third dose of the SARS-CoV-2 mRNA vaccine. The results suggest that antibody durability persists up to 6 months following three doses of the SARS-CoV-2 mRNA in aSOTRs. Demography and transplant characteristics did not differ for those who experienced antibody weaning. Breakthrough infections did occur, reflecting immune-evasive nature of novel variants such as Omicron.

IgG antibody levels against the SARS-CoV-2 spike protein in mother-child dyads after COVID-19 vaccination.

We aimed to assess IgG antibodies against the SARS-CoV-2 spike protein (anti-SARS-CoV-2 S IgG) in vaccinated mothers and their infants at delivery and 2-3months of age. We conducted a prospective study on mothers who received at least one dose of the COVID-19 vaccine (Pfizer-BNT162b2, Moderna mRNA-1273, or Oxford-AstraZeneca ChAdOx1-S) during pregnancy and on their infants. The baseline was at the time of delivery (n = 93), and the end of follow-up was 2 to 3months post-partum (n = 53). Serum anti-SARS-CoV-2 S IgG titers and ACE2 binding inhibition levels were quantified by immunoassays. Mothers and infants had high anti-SARS-CoV-2 S IgG titers against the B.1 lineage at birth. However, while antibody titers were maintained at 2-3months post-partum in mothers, they decreased significantly in infants (p < 0.001). Positive and significant correlations were found between anti-SARS-CoV-2 S IgG titers and ACE2-binding inhibition levels in mothers and infants at birth and 2-3months post-partum (r > 0.8, p < 0.001). Anti-S antibodies were also quantified for the Omicron variant at 2-3months post-partum. The antibody titers against Omicron were significantly lower in mothers and infants than those against B.1 (p < 0.001). Again, a positive correlation was observed for Omicron between IgG titers and ACE2-binding inhibition both in mothers (r = 0.818, p < 0.001) and infants (r = 0.386, p < 0.005). Previous SARS-CoV-2 infection and COVID-19 vaccination near delivery positively impacted anti-SARS-CoV-2 S IgG levels. COVID-19 mRNA vaccines induce high anti-SARS-CoV-2 S titers in pregnant women, which can inhibit the binding of ACE2 to protein S and are efficiently transferred to the fetus. However, there was a rapid decrease in antibody levels at 2 to 3months post-partum, particularly in infants.

Comparison of Post-Vaccination Response between mRNA and Vector Vaccines against SARS-CoV-2 in Terms of Humoral Response after Six Months of Observation.

The emergence of the SARS-CoV-2 (COVID-19) pandemic has accelerated work on the creation of effective vaccines, both in terms of previously known vector vaccines and new-generation (mRNA) vaccines. The scientific research on vaccination against COVID-19 infection is limited; therefore, understanding how the immune system responds to vaccines is critical. In our study, we conducted a long-term analysis of the presence and persistence of the immune response via chemiluminescence, analyzing the level of IgG antibodies and neutralizing antibodies in subjects vaccinated with two types of mRNA (Comirnaty) and vector (Vaxzevria) vaccines. Healthcare workers and a group of teachers were recruited for this study according to the 2021 government-launched vaccination calendar. They received two doses of the Comirnaty or Vaxzevria vaccine. SRBD (spike-receptor binding domain) IgG antibody levels were measured monthly for 6 consecutive months with a chemiluminescent assay (CLIA) and neutralizing antibodies for two periods-1 and 5 months from the completion of the vaccination course. 168 people were recruited for this study: 135 people for the mRNA vaccine group and 33 people for the vector vaccine group. Comparing the serum IgG levels between the two types of vaccines, a significant difference in median values can be noted at all time points. In consecutive months, the mRNA-vaccinated group exhibited significantly higher SRBD levels compared to the vector group, with peak concentrations at one month after the complete vaccination cycle (745 AU/mL vs. 15.44 AU/mL; p < 0.001). Peak antibody concentration for the vector vaccine was observed one month later, at the third follow-up visit; however, the median IgG concentration was almost 7.7 times higher for the Comirnaty group. Both products were effective in stimulating neutralizing antibody production after vaccination. Higher median values were observed for the mRNA vaccines in both evaluations. At first evaluation, the median value for NA concentration in the Comirnaty group was 6 times higher than in the Vaxzevria group (median value 12.23 [IQR 27.3] vs. 1.7 [IQR 3.3]; p < 0.001. People vaccinated with the mRNA vaccine (Comirnaty) showed a stronger immune response to the vaccination than the group of people administered the vector vaccine (Vaxzevria). The Comirnaty group showed higher levels of IgG, including neutralizing antibodies, at all time points during the follow-up period, and this was independent of having had a SARS-CoV-2 infection. A natural decrease in antibody levels was seen within 6 months. A booster vaccination may be required. No serious side effects were observed in either group.

Autoantibodies against laminin-521 are pathogenic in anti-glomerular basement membrane disease

Anti-glomerular basement membrane (anti-GBM) disease is an organ-specific autoimmune disorder characterized by autoantibodies against GBM components. Evidence from human inherited kidney diseases and animal models suggests that the α, β, and γ chains of laminin-521 are all essential for maintaining the glomerular filtration barrier. We previously demonstrated that laminin-521 is a novel autoantigen within the GBM and that autoantibodies to laminin-521 are present in about one-third of patients. In the present study, we investigated the pathogenicity of autoantibodies against laminin-521 with clinical and animal studies. Herein, a rare case of anti-GBM disease was reported with circulating autoantibodies binding to laminin-521 but not to the NC1 domains of α1-α5(IV) collagen. Immunoblot identified circulating IgG from this patient bound laminin α5 and γ1 chains. A decrease in antibody levels was associated with improved clinical presentation after plasmapheresis and immunosuppressive treatments. Furthermore, immunization with laminin-521 in female Wistar-Kyoto rats induced crescentic glomerulonephritis with linear IgG deposits along the GBM, complement activation along with infiltration of T cells and macrophages. Lung hemorrhage occurred in 75.0% of the rats and was identified by the presence of erythrocyte infiltrates and hemosiderin-laden macrophages in the lung tissue. Sera and kidney-eluted antibodies from rats immunized with laminin-521 demonstrated specific IgG binding to laminin-521 but not to human α3(IV)NC1, while the opposite was observed in human α3(IV)NC1-immunized rats. Thus, our patient data and animal studies imply a possible independent pathogenic role of autoantibodies against laminin-521 in the development of anti-GBM disease.

KADAR ANTIBODI IgG SARS COV-2 SETELAH VAKSINASI COVID-19 DOSIS LANJUTAN

COVID-19 is a problem throughout the world, including Indonesia. One of the efforts to overcome the COVID-19 pandemic is vaccination. A follow-up or booster dose was needed to increase individual protection because there was a decrease in antibodies 6 months after receiving vaccination. This study aimed to determine SARS-CoV-2 IgG antibody levels before and after 8 months of the third booster vaccination. This research method was observational with a longitudinal, cohort approach to 27 samples using a consecutive sampling technique at the Health Polytechnic of the Ministry of Health, Jakarta III in April-November 2022. The data collection techniques used questionnaires and venous blood sampling to examine quantitative Anti-SARS CoV-2 Ig G levels using the CMIA (Chemiluminescent microparticle immunoassay) method with the Architect tool which was carried out twice, namely before administration and 8 months after the third booster vaccination with a heterologous vaccine. Data were analyzed using a statistical test of the difference between the means of two groups. Based on the research results, although statistically there was no significant difference between before and 8 months after vaccination (p=0.055), there was a decrease in the mean quantitative Anti-SARS CoV-2 IgG level of 5301.24 AU/mL. As many as 63% of subjects experienced a decrease in antibody levels 8 months after vaccination compared to before the third booster vaccination. Longitudinal studies are needed to determine protective antibody levels.

A cohort study reveals different dynamics of SARS-CoV-2-specific antibody formation after Comirnaty and Vaxzevria vaccination

The Coronavirus (COVID-19) Disease Pandemic, caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), has affected millions of people worldwide, prompting a collective effort from the global scientific community to develop a vaccine against it. This study purports to investigate the influence of factors such as sex, age, type of vaccination (Comirnaty, BNT162b2, Pfizer Inc. or Vaxzevria, ChAdOx1-S, Oxford/AstraZeneca), and time since vaccine administration on the process of antibody production. Both of them are based on the introduction of SARS-CoV-2 spike protein (S protein) to the body using different mechanisms (mRNA and recombinant adenovirus, respectively). S protein is responsible for host cell attachment and penetration via its receptor-binding domain (RBD domain). The level of anti-RBD IgG antibodies was tested with an ELISA-based immunodiagnostic assay in serum samples from a total of 1395 patients at 3 time points: before vaccination, after the first dose, and after the second dose. Our novel statistical model, the Generalized Additive Model, revealed variability in antibody production dynamics for both vaccines. Interestingly, no discernible variation in antibody levels between men and women was found.A nonlinear relationship between age and antibody production was observed, characterized by decreased antibody levels for people up to 30 and over 60 years of age, with a lack of correlation in the middle age range. Collectively, our findings further the understanding of the mechanism driving vaccine-induced immunity. Additionally, we propose the Generalized Additive Model as a standardized way of presenting data in similar research.

A third vaccine dose equalises the levels of effectiveness and immunogenicity of heterologous or homologous COVID-19 vaccine regimens, Lyon, France, December 2021 to March 2022.

BackgroundTo cope with the persistence of the COVID-19 epidemic and the decrease in antibody levels following vaccination, a third dose of vaccine has been recommended in the general population. However, several vaccine regimens had been used initially for the primary vaccination course, and the heterologous Vaxzevria/Comirnaty regimen had shown better efficacy and immunogenicity than the homologous Comirnaty/Comirnaty regimen.AimWe wanted to determine if this benefit was retained after a third dose of an mRNA vaccine.MethodsWe combined an observational epidemiological study of SARS-CoV-2 infections among vaccinated healthcare workers at the University Hospital of Lyon, France, with a prospective cohort study to analyse immunological parameters before and after the third mRNA vaccine dose.ResultsFollowing the second vaccine dose, heterologous vaccination regimens were more protective against infection than homologous regimens (adjusted hazard ratio (HR) = 1.88; 95% confidence interval (CI): 1.18-3.00; p = 0.008), but this was no longer the case after the third dose (adjusted HR = 0.86; 95% CI: 0.72-1.02; p = 0.082). Receptor-binding domain-specific IgG levels and serum neutralisation capacity against different SARS-CoV-2 variants were higher after the third dose than after the second dose in the homologous regimen group, but not in the heterologous group.ConclusionThe advantage conferred by heterologous vaccination was lost after the third dose in terms of both protection and immunogenicity. Immunological measurements 1 month after vaccination suggest that heterologous vaccination induces maximal immunity after the second dose, whereas the third dose is required to reach the same level in individuals with a homologous regimen.

Evaluation of antibody kinetics and durability in health individuals vaccinated with inactivated COVID-19 vaccine (CoronaVac): a cross-sectional and cohort study in Zhejiang, China.

Although inactivated COVID-19 vaccines are proven to be safe and effective in the general population, the dynamic response and duration of antibodies after vaccination in the real world should be further assessed. We enrolled 1067 volunteers who had been vaccinated with one or two doses of CoronaVac in Zhejiang Province, China. Another 90 healthy adults without previous vaccinations were recruited and vaccinated with three doses of CoronaVac, 28 days and 6 months apart. Serum samples were collected from multiple timepoints and analyzed for specific IgM/IgG and neutralizing antibodies (NAbs) for immunogenicity evaluation. Antibody responses to the Delta and Omicron variants were measured by pseudovirus-based neutralization tests. Our results revealed that binding antibody IgM peaked 14-28 days after one dose of CoronaVac, while IgG and NAbs peaked approximately 1 month after the second dose then declined slightly over time. Antibody responses had waned by month 6 after vaccination and became undetectable in the majority of individuals at 12 months. Levels of NAbs to live SARS-CoV-2 were correlated with anti-SARS-CoV-2 IgG and NAbs to pseudovirus, but not IgM. Homologous booster around 6 months after primary vaccination activated anamnestic immunity and raised NAbs 25.5-fold. The neutralized fraction subsequently rose to 36.0% for Delta (p=0.03) and 4.3% for Omicron (p=0.004), and the response rate for Omicron rose from 7.9% (7/89)-17.8% (16/90). Two doses of CoronaVac vaccine resulted in limited protection over a short duration. The inactivated vaccine booster can reverse the decrease of antibody levels to prime strain, but it does not elicit potent neutralization against Omicron; therefore, the optimization of booster procedures is vital. Key Research and Development Program of Zhejiang Province; Key Program of Health Commission of Zhejiang Province/ Science Foundation of National Health Commission; Major Program of Zhejiang Municipal Natural Science Foundation; Explorer Program of Zhejiang Municipal Natural Science Foundation.

The Effect of Antipyretics on Antibody Production in Pediatric Patients Post-Vaccination

The COVID-19 pandemic and subsequent vaccine administration renewed the question of the potential effect that antipyretics have on antibody levels post-vaccination in pediatric patients. Many patients take antipyretics to reduce side effects and fevers as they have anti-inflammatory properties. We reviewed the literature for studies examining the question of whether the consumption of antipyretics reduced post-vaccination antibody titers. We found that there is a correlation between antipyretics decreasing antibody production in the pediatric population when given prophylactically. However, to confirm these results more in depth studies are required. Our PICO question allowed us to narrow our focus into the pediatric population, antipyretic intervention, and antibody levels. Our results reflect a significant decrease in antibody levels, but antipyretics do not affect clinical efficiency of the vaccines. Our world relies on vaccine technology and it has allowed us to survive pandemics like the COVID 19 outbreak. In order to keep using these innovations safely, more trials must be conducted.

The association of neonatal SARS-CoV-2 anti-spike protein receptor-binding domain antibodies at delivery with infant SARS-CoV-2 infection under the age of 6 months: a prospective cohort study

ObjectivesThe aim of this study was to assess the association between neonatal SARS-CoV-2 antibody level at delivery and infant SARS-CoV-2 infection under the age of 6 months and to identify predictive factors for neonatal antibody level at delivery. MethodsIn a prospective observational study, conducted between September 2021 and mid-February 2022, cord blood sera were tested for SARS-CoV-2 anti-spike receptor-binding domain antibodies after maternal BNT162b2 vaccination or infection. Infants were followed up for 6 months for SARS-CoV-2 infection. ResultsSixty-seven mother-infant dyads were enrolled; nine of those did not meet the eligibility criteria. Of the 58 mother-infant dyads included, 6-month follow-up data were available for 57 mother-infant dyads. The mean ± standard deviation log SARS-CoV-2 anti-spike antibody level at delivery was lower among infants who were COVID-19 positive versus negative during follow-up (3.41 ± 0.74 AU/mL, n = 12; vs. 3.87 ± 0.84 AU/mL, n = 46; p 0.036); a log titre of ≥4.07 AU/mL (11 750) at delivery was associated with a significantly lower likelihood of infant infection (1/26 vs. 11/32 in infants with antibody level of <4.07 log AU/mL, OR = 0.076 [95% CI, 0.076, 0.64], p 0.018). A spline curve model showed a linear decrease in antibody levels when the last dose was administered at ≤30 weeks of gestation (50 days before delivery), after which the antibody levels increased (R2 = 0.50). In multivariate analysis, more vaccine doses, prior maternal infection, and last administered dose at ≥31 weeks of gestation were associated with higher antibody levels at delivery. DiscussionHigher anti-spike antibodies at delivery were associated with decreased risk of COVID-19 at the age of <6 months; the antibody level decreased linearly when the last dose was administered at ≤30 weeks of gestation. Future research should assess the effectiveness of a second booster during pregnancy against infant infection.

Immunogenicity of the ChAdOx1 nCoV-19 vaccine in patients with hematologic malignancies.

The present study aimed to study the immunogenicity of the ChAdOx1 nCoV-19 vaccine in patients with hematologic malignancies. This prospective cohort study of hematology patients aimed to evaluate their antibody levels against the receptor-binding domain of the severe acute respiratory syndrome coronavirus 2 spike protein and seroconversion rates following two doses of the ChAdOx1 nCoV-19 vaccine. Between June and July 2021, we enrolled 61 patients and included 44 patients in our analysis. Antibody levels were assessed 8 and 4 weeks after the first and second injections, respectively, and compared with those of a healthy group. Eight weeks after the first dose, the geometric mean antibody level was 1.02 binding antibody units (BAU)/mL in the patient group and 37.91 BAU/mL in the healthy volunteer group (p<0.01). Four weeks after the second dose, the geometric mean antibody level was 9.44 BAU/mL in patients and 641.6 BAU/mL in healthy volunteers (p<0.01). The seroconversion rates 8 weeks after the first dose were 27.27% and 98.86% in the patient and healthy volunteer groups, respectively (p<0.001). The seroconversion rate 4 weeks after the second dose was 47.73% in patients and 100% in healthy volunteers. Factors leading to lower seroconversion rates were rituximab therapy (p=0.002), steroid therapy (p<0.001), and ongoing chemotherapy (p=0.048). Factors that decreased antibody levels were hematologic cancer (p<0.001), ongoing chemotherapy (p=0.004), rituximab (p<0.001), steroid use (p<0.001), and absolute lymphocyte count <1,000/mm3 (p=0.009). Immune responses were impaired in individuals with hematologic malignancies, particularly patients undergoing ongoing therapy and B-cell-depleting therapy. Additional vaccinations should be considered for these patients, and further investigated.

How many is good enough? An analysis of serological follow-up after vaccination against SARS-CoV-2

Abstract Introduction Despite vaccinations available worldwide, patients and healthcare workers still struggle with COVID-19. Previously we observed in some convalescents surprisingly lower antibody levels after a second dose of SARS-CoV-2 vaccine compared to the first dose. Six months after full vaccination we obtained follow-up results of 87 patients divided into 3 groups: (A) convalescents with higher antibody levels after second dose of vaccine compared to first dose, (B) naïve patients, (C) convalescents with decreasing antibody level after second dose compared to first dose. Materials and Methods Patients’ anti-SARS-CoV-2 antibody levels were checked by the anti-SARS-CoV-2 QuantiVac ELISA (IgG) (EUROIMMUN MedicinischeLabordiagnostica AG, Luebeck, Germany) test, as before, and prior to the blood sampling patients completed a questionnaire regarding, inter alia, general condition, smoking, flu vaccination. Results Thanks to this follow-up we concluded that none of the patients suffered from symptomatic SARS-CoV-2 infection within 6 months after vaccination. Decline of antibody levels 6 months after vaccination was observed in all groups. Convalescent group A lost more antibodies in the mentioned period of time than group B or C. Group C presented still high results, higher than in group B (p = 0.007), but lower than in group A (p = 0.048). Conclusions Temporary decrease of antibody levels in convalescents after the second dose of SARS-CoV-2 vaccination did not imply further consequences in the form of important antibody level differences 6 months after vaccination. Patients’ overweight could have an impact on antibody production but only after natural infection. It did not affect obtained results after vaccinations.

A Retrospective Study with a Commercial Vaccine against Lyme Borreliosis in Dogs Using Two Different Vaccination Schedules: Characterization of the Humoral Immune Response

Lyme borreliosis, a multisystemic disease caused by spirochetes of the genus Borrelia, is the most common tick-borne disease in the northern hemisphere. Differently from human medicine, several vaccines are available for dogs. To provide the best protection possible, vaccination schemes should be adapted regularly to meet the needs resulting from an increased tick exposure risk due to an inescapable climate change. In this retrospective study, a total of 183 vaccinations were performed with a commercial, multivalent vaccine against Lyme borreliosis, and vaccinated dogs were monitored over an observation period of 13 months. Dogs were either vaccinated on days 0 and 21 and a booster on day 365 (standard vaccination schedule), or with an additional booster vaccination on day 180. Canine serum samples were then tested for their borrelia-specific antibody levels using a two-tiered test system consisting of a kinetic ELISA followed by a line immunoassay. Dogs vaccinated with the standard vaccination schedule displayed decreasing antibody levels between days 120 and 360, which is probably insufficient to prevent an infection with borreliae. In contrast, the additional booster vaccination received on day 180 intercepts this decline in antibody levels between days 225 and 360, providing a sufficient immunity to prevent infection. The results from this retrospective study allow us to recommend a basic vaccination schedule with an additional booster vaccination on day 180 to ensure the best possible protection for dogs against Lyme borreliosis.

Effect of Previous Infection and Vaccination on Incidence of Covid-19 among Healthcare Workers and Antibody Response

Aims: To correlate the effect of previous COVID-19 infection and vaccination on incidence of COVID -19 infection .&#x0D; Study Design: It is a prospective observational study.&#x0D; Place and Duration of Study: Eternal Heart Care Centre and Research Institute, Jaipur, India.&#x0D; Methodology: We included 405 healthcare workers with COVID-19 positive infection, with or without the symptoms. Clinical as well as hematological examination were done.&#x0D; Results: Our study showed 75.6% seropositivity rate even 6 months after vaccination in which seropositivity was significantly higher in people who had past history of COVID-19 .Antibody levels were highest when observed one month after vaccination. A decrease in antibody levels over time after vaccination is observed. Seropositivity rate was significantly higher in people who were less than 40 years old.&#x0D; Conclusion: A decrease in antibody levels over time after vaccination is observed and this showed that the rate of infection decreases after receiving vaccination.

Durability of Antibody Response Against Hepatitis B Virus for a Decreased Crowd: A Retrospective Polycentric Cohort Study from a 10-Year Follow-Up Clinical Study.

Hepatitis B surface antibody (HBsAb) plays an important role in the prevention of hepatitis B virus (HBV) infection, especially in immunocompromised individuals and in those infected with HBV.HBsAb levels often fluctuate and decrease.This study aimed to determine the regularity of HBsAb persistence among different populations. Moreover, the risk factors and the optimal cutoff value were determined to predict a decreasing population in HBsAb level. The study involved 182 participants, including 76 patients with a 25% decrease in HBsAb levels and 106 patients with an HBsAb decrease rate of >50%. Both hepatitis B core antibody negative and positive patients were included.These patients were followed up for 10 years. The follow-up demographic and laboratory data were recorded and compared among the groups. Fluctuations in HBsAb data and HBsAb persistent immunity were evaluated. The independent factors and the optimal cutoff value were recorded. The first HBsAb median of Group 4 was lower than that of the other groups, and its median was 50.8 mlU/mL. In addition, the persistent immunity of the case groups was shorter than that of the control groups (p < 0.05). Furthermore, previous HBV history, use of antiviral drugs, and low levels of first HBsAb were independent risk factors in people with obviously decreased antibody levels. Also, when the optimum cutoff value on the receiver operating characteristic curve of the HBsAb difference value was taken as 8.53 mIU/mL, its sensitivity and specificity were 94% and 70% between the control and case groups, respectively. To maintain optimal immunity against HBV infection, patients with a previous HBV history, those taking antiviral drugs, and/or those with low levels of HBsAb should be reimmunized with the hepatitis B vaccine in a timely manner.

The risk factors of SARS-CoV-2 antibody level differences in healthcare workers post vaccination in Siloam hospitals: A nationwide multicenter study

BackgroundSeveral vaccines have been approved against COVID-19, and five have been used in Indonesia. Due to the decrease in antibody levels three to six months after the second dose of CoronaVac, healthcare workers received the third booster of mRNA vaccine (mRNA-1273) to increase the antibody level. This study aimed to evaluate the risk factors of anti-S-RBD IgG levels differences in healthcare workers.MethodsThis study is a retrospective cohort study of 576 healthcare workers without previous SARS-CoV-2 infection who received two doses of CoronaVac and the third dose of mRNA-1273 six months after the second dose. Blood samples were obtained 2nd, 6th, 12th, and 24th weeks after the second dose of CoronaVac vaccine administration, with mRNA-1273 booster on week 20. Quantitative measurements of IgG antibodies were performed with Elecsys Anti-SARS-CoV-2 S immunoassay. We identify the baseline factors predicting post-vaccination antibody titers using univariate and multivariate linear regression analysis.ResultsThis study comprised 576 participants aged 32 years old, 72.05% female, and 45.84% from high-risk occupation subgroups. The median antibodies titer level on the 2nd, 6th, 12th, and 24th weeks after the second vaccine dose administration were 40.99 u/mL, 42.01 u/mL, 54.78 u/mL, and 23,225 u/mL. Antibody levels trended highest in female and younger age group (20-29 years old).ConclusionThe third dose of vaccine increased the quantitative SARS-CoV-2 spike IgG antibody titers and eliminated differences in antibodies titer by gender. Keywords: Antibodies titer, COVID-19, Immune response, S-RBD IgG, Vaccine