Post-vaccination Antibody Research Articles

Association between antibody responses post-vaccination and severe COVID-19 outcomes in Scotland

Several population-level studies have described individual clinical risk factors associated with suboptimal antibody responses following COVID-19 vaccination, but none have examined multimorbidity. Others have shown that suboptimal post-vaccination responses offer reduced protection to subsequent SARS-CoV-2 infection; however, the level of protection from COVID-19 hospitalisation/death remains unconfirmed. We use national Scottish datasets to investigate the association between multimorbidity and testing antibody-negative, examining the correlation between antibody levels and subsequent COVID-19 hospitalisation/death among double-vaccinated individuals. We found that individuals with multimorbidity ( ≥ five conditions) were more likely to test antibody-negative post-vaccination and 13.37 [6.05–29.53] times more likely to be hospitalised/die from COVID-19 than individuals without conditions. We also show a dose-dependent association between post-vaccination antibody levels and COVID-19 hospitalisation or death, with those with undetectable antibody levels at a significantly higher risk (HR 9.21 [95% CI 4.63–18.29]) of these serious outcomes compared to those with high antibody levels.

The influence of adjuvants ISA 61 and ISA 50 on the antigenic activity, the ability to form colostral immunity and the effectiveness of experimental samples of the vaccine <i>KOMBOVAC-A</i>

The article provides a comparative assessment of two experimental samples of the seven-component vaccine KOMBOVAС-A, manufactured with adjuvants ISA 61 and ISA 50, in terms of: antigenic activity (in laboratory and naturally susceptible animals); influence on the formation of colostral immunity in calves when vaccinating pregnant cows, as well as effectiveness in livestock farming conditions unfavorable for the main respiratory and intestinal diseases of calves of viral etiology. It was found that the vaccine sample based on the ISA 61 adjuvant had a higher antigenic activity compared to a similar sample based on the ISA 50 adjuvant, inducing a higher level of synthesis of post-vaccination antibodies. The use of the vaccine in conditions of a dysfunctional livestock farm has reduced the morbidity and mortality of calves, while the vaccine sample made on the basis of ISA 61 oil proved to be more effective.

Association between adverse events after COVID-19 vaccination and anti-SARS-CoV-2 antibody concentrations, the Netherlands, May 2021 to November 2022: a population-based prospective cohort study.

BackgroundNon-severe adverse events (AE) including pain at injection site or fever are common after COVID-19 vaccination.AimTo describe determinants of AE after COVID-19 vaccination and investigate the association between AE and pre- and post-vaccination antibody concentrations.MethodsParticipants of an ongoing prospective cohort study (VASCO) completed a questionnaire on AE within 2 months after vaccination and provided 6 monthly serum samples during May 2021-November 2022. Logistic regression analyses were performed to investigate AE determinants after mRNA vaccination, including pre-vaccination Ig antibody concentrations against the SARS-CoV-2 spike protein receptor binding domain. Multivariable linear regression was performed in SARS-CoV-2-naive participants to assess the association between AE and log-transformed antibody concentrations 3-8 weeks after mRNA vaccination.ResultsWe received 47,947 completed AE questionnaires by 28,032 participants. In 42% and 34% of questionnaires, injection site and systemic AE were reported, respectively. In 2.2% of questionnaires, participants sought medical attention. AE were reported more frequently by women, younger participants (< 60 years), participants with medical risk conditions and Spikevax recipients (vs Comirnaty). Higher pre-vaccination antibody concentrations were associated with higher incidence of systemic AE after the second and third dose, but not with injection site AE or AE for which medical attention was sought. Any AE after the third dose was associated with higher post-vaccination antibody concentrations (geometric mean concentration ratio: 1.38; 95% CI: 1.23-1.54).ConclusionsOur study suggests that high pre-vaccination antibody levels are associated with AE, and experiencing AE may be a marker for higher antibody response to vaccination.

RBD mutations at the residues K417, E484, N501 reduced immunoreactivity with antisera from vaccinated and COVID-19 recovered patients.

It is unclear whether induced spike protein-specific antibodies due to infections with SARS-CoV-2 or to the prototypic Wuhan isolate-based vaccination can immune-react with the emerging variants of SARS-CoV-2. The main objective of the study was to measure the immunoreactivity of induced antibodies postvaccination with Covishield™ (ChAdOx1 nCoV-19 coronavirus vaccines) or infections with SARS-CoV-2 by using selected peptides of the spike protein of wild type and variants of SARS-CoV-2. Thirty patients who had recovered from SARS-CoV-2 infections and 30 individuals vaccinated with both doses of Covishield™ were recruited for the study. Venous blood samples (5 mL) were collected at a single time point from patients within 3-4 weeks of recovery from SARS-CoV-2 infections or receiving both doses of Covishield™ vaccines. The serum levels of total immunoglobulin were measured in both study groups. A total of 12 peptides of 10 to 24 amino acids length spanning to the receptor-binding domain (RBD) of wild type of SARS-CoV-2 and their variants were synthesized. The serum levels of immune-reactive antibodies were measured using these peptides. The serum levels of total antibodies were found to be significantly (p<0.001) higher in the vaccinated individuals as compared to COVID-19 recovered patients. Our study reported that the mutations in the RBD at the residues K417, E484, and N501 have been associated with reduced immunoreactivity with anti-sera of vaccinated people and COVID-19 recovered patients. The amino acid substitutions at the RBD of SARS-CoV-2 have been associated with a higher potential to escape the humoral immune response.

Multiplex gradient immunochip for detection of post-vaccinal antibodies in poultry.

Multiplex analysis as an immunochip-in-a well format for simultaneous detection of post-vaccinal antibodies to three poultry infections (Newcastle disease, infectious bronchitis and bursal disease) in one chicken sera was developed. The immunochip had a microarray format printed on the bottom of a standard microtiter plate well and consisted of 36 microspots (d = 400μm each) with three lines of viral antigens absorbed in a gradient of five decreasing concentrations. Optimization of assay conditions revealed the necessity of careful choice of the reaction buffer due to the high tendency of chicken IgY to exhibit unspecific binding. The best results were obtained for PBS buffer (pH 6.0) supplied with 0.1% Tween 20. Assay results were visualized by a number of coloured microspots that were correlated with the specific antibody titre in the analysed serum. High (> 8000), medium (3000-8000) or low (1000-3000) antibody titre level for each of three infections could be quickly assessed in one probe visually or with the help of smartphone. ELISA results (antibody titres) and visual gradient immunochip results interpretation (high, medium, low antibody level/titre) for 63 chicken sera with multiple levels of post-vaccinal antibodies against Newcastle disease, infectious bronchitis and bursal disease were in good correlation.

Evaluation of the Development of Post-Vaccination Immunity against Selected Bacterial Diseases in Children of Post-Solid-Organ-Transplant Mothers.

Pregnancy after organ transplantation is considered high-risk and requires supervision in specialized centers. The impact of immunosuppression on the developing fetus is still the subject of research. It has been shown that it affects lymphocyte populations in the first year of life. For this reason, researchers suggest postponing mandatory infant vaccinations. The aim of the study was to analyze the influence of intrauterine exposure of the fetus to immunosuppression on the immunogenicity of protective vaccinations against selected bacterial pathogens. The ELISA method was used to determine the concentration of post-vaccination IgG antibodies against diphtheria, tetanus, pertussis, tuberculosis, H. influenzae type B, and S. pneumoniae in 18 children of mothers who underwent organ transplantation. The results were compared with the control group (n = 21). A comparison of the incidence of adverse post-vaccination reactions between the analyzed groups was also performed. There were no statistically significant differences in the immunogenicity of the analyzed vaccines between children of mothers who underwent organ transplantation and the age-matched general pediatric population. There were no differences in the incidence of adverse post-vaccination reactions between the analyzed groups. The obtained results do not indicate the need to modify the current protective vaccination schemes against bacterial pathogens in children of mothers who underwent organ transplantation.

Cross-Reactive Antibody Responses to Coronaviruses Elicited by SARS-CoV-2 Infection or Vaccination.

The newly emerged SARS-CoV-2 possesses shared antigenic epitopes with other human coronaviruses. We investigated if COVID-19 vaccination or SARS-CoV-2 infection may boost cross-reactive antibodies to other human coronaviruses. Prevaccination and postvaccination sera from SARS-CoV-2 naïve healthy subjects who received three doses of the mRNA vaccine (BioNTech, BNT) or the inactivated vaccine (CoronaVac, CV) were used to monitor the level of cross-reactive antibodies raised against other human coronaviruses by enzyme-linked immunosorbent assay. In comparison, convalescent sera from COVID-19 patients with or without prior vaccination history were also tested. Pseudoparticle neutralization assay was performed to detect neutralization antibody against MERS-CoV. Among SARS-CoV-2 infection-naïve subjects, BNT or CV significantly increased the anti-S2 antibodies against Betacoronaviruses (OC43 and MERS-CoV) but not Alphacoronaviruses (229E). The prevaccination antibody response to the common cold human coronaviruses did not negatively impact the postvaccination antibody response to SARS-CoV-2. Cross-reactive antibodies that binds to the S2 protein of MERS-CoV were similarly detected from the convalescent sera of COVID-19 patients with or without vaccination history. However, these anti-S2 antibodies do not possess neutralizing activity in MERS-CoV pseudoparticle neutralization tests. Our results suggest that SARS-CoV-2 infection or vaccination may potentially modulate population immune landscape against previously exposed or novel human coronaviruses. The findings have implications for future sero-epidemiological studies on MERS-CoV.

Sex Differences in Exercise-Induced Modulation of the Humoral Immune Response to Influenza Vaccination

Physical activity is known to modulate immune cell function and understanding its role in vaccine-induced immunity is critical for both optimizing vaccine strategies and implementing lifestyle factors that contribute to better immune health. This study aimed to elucidate the impact of physical activity on antibody responses following influenza vaccination, with a specific focus on biological sex differences among male and female cross-country athletes. Based on previous studies, we hypothesized that physical activity would increase immune responses, regardless of biological sex. Two cohorts of male and female Division III college cross-country runners and two cohorts of non-athletes (no physical activity) participated in this longitudinal investigation. Studies were conducted in two separate influenza seasons where participants received a quadrivalent seasonal influenza vaccine (2020-21 and 2022-23). An estimated non-adjusted VO2 max was calculated, and a survey was administered to identify overall health status prior to the start of the study. Blood samples were collected at predefined intervals to assess pre- and post-vaccination antibody responses specific for the H1N1 component of each seasonal influenza vaccine. VO2 max, a measure of overall fitness, was higher in the athletes as compared to those participants who were not physically active, and these results were consistent among both males and females. All participants mounted an immune response to the seasonal influenza vaccine as indicated by a rise in vaccine-specific antibody titers from pre-vaccination to post-vaccination. However, the differences in titers were sex specific, with greater neutralizing antibody titers in females as compared to males — regardless of their level of physical activity. When data were further partitioned by physical activity level, it was identified that although males have lower antibody responses than females, males that were cross country runners had significantly greater antibody responses than males that were not physically active. This study contributes valuable insights into the complex interplay between exercise, sex, and immune responses. Understanding these dynamics could inform recommendations for individuals to be engaged in regular physical activity to optimize overall immune health. This research was funded by a College of Saint Benedict and Saint John's University Faculty Development and Research Committee Award. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Anti-SARS-CoV-2 Antibodies Level and COVID-19 Vaccine Boosters among Healthcare Workers with the Highest SARS-CoV-2 Infection Risk-Follow Up Study.

During the COVID-19 pandemic, several vaccines were developed to limit the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, due to SARS-CoV-2 mutations and uneven vaccination coverage among populations, a series of COVID-19 waves have been caused by different variants of concern (VOCs). Despite the updated vaccine formulations for the new VOC, the benefits of additional COVID-19 vaccine doses have raised many doubts, even among high-risk groups such as healthcare workers (HCWs). We examined the factors underlying hesitancy to receive COVID-19 booster vaccine doses and analysed the anti-SARS-CoV-2 IgG antibody response after booster vaccination among HCWs. Our study found that 42% of the HCWs were hesitant about the second booster dose, while 7% reported no intent to get vaccinated with any additional doses. As reasons for not vaccinating, participants most frequently highlighted lack of time, negative experiences with previous vaccinations, and immunity conferred by past infections. In addition, we found the lowest post-vaccination antibody titres among HCWs who did not receive any vaccine booster dose and the highest among HCWs vaccinated with two booster doses.

Reduction of adverse reactions and correlation between post-vaccination fever and specific antibody response across successive SARS-CoV-2 mRNA vaccinations

BackgroundSARS-CoV-2 mRNA vaccination, recognized for high immunogenicity, frequently induces adverse reactions, especially fever. We previously reported a correlation between post-vaccination fever and specific antibody responses to the primary series and first booster. We herein report changes in adverse reactions and the correlation between post-vaccination fever and antibody responses across successive vaccinations, from monovalent to bivalent mRNA vaccines. MethodsThis cohort study was conducted at a Japanese hospital to investigate adverse reactions to the monovalent primary, first booster, and BA.4/5 bivalent BNT162b2 vaccinations. Local and systemic reactions were reported through a self-reporting diary after each dose. The spike-specific IgG titers were measured following each vaccination. ResultsAcross 727 vaccinations in the vaccine series, the bivalent booster induced fewer adverse reactions than earlier doses. Fever ≥ 38.0 °C was significantly less frequent in the bivalent booster (12.3 %) compared to the primary series and monovalent booster (22.0 %, 26.2 %, p < 0.001). Reaction severity was also reduced in the bivalent booster. In the analysis of 70 participants with complete data for all doses, post-vaccination fever ≥ 38.0 °C exhibited the highest relative risk (RR) among all solicited reactions throughout the vaccine series (RR: 5.24 [95 % CI: 2.40–11.42] for monovalent and 6.24 [95 % CI: 2.14–18.15] for bivalent). The frequency of fever ≥ 38.0 °C after all doses was 8.6 % (6/70), with no fever ≥ 39.0 °C across all vaccinations. A high-grade post-vaccination fever was correlated with higher IgG titers, with multivariate analyses confirming this correlation as independent for each dose and unaffected by previous post-vaccination fever. ConclusionsThe bivalent mRNA vaccine booster showed fewer and milder adverse reactions than the monovalent doses. Although vaccinees with a history of post-vaccination fever were more likely to experience fever after a subsequent dose, such recurrences were infrequent. A correlation between post-vaccination fever and increased IgG titers was identified for each vaccination, irrespective of post-vaccination fever history.

Effect of physical exercise on inactivated COVID-19 vaccine antibody response in the elderly.

Physical exercise has been proposed as a new alternative to chemical adjuvants. To investigate the relationship between regular exercise and post-vaccination antibody response in the elderly. The study was conducted with the elderly over the age of 65. 30participants we randomized into 2groups and divided into exercise and control groups. The experimental group received a 12-week exercise program. The control group was followed up without any exercise. The day on which the second dose of the vaccine was administered to all participants was considered day 0. The antibody level in the serum samples was taken 15days and 12weeks after the vaccination. The antibody concentration was measured after the second dose of vaccination. The mean antibody level in the control group was 69.4U/ml and 56.4U/ml 15days and 12weeks after the second vaccination. The mean antibody level in the exercise group was 74U/ml and 71.6U/ml 15days and 12weeks after the second vaccination. Regular exercise of light to moderate intensity may increase post-vaccination antibody response in the elderly. Therefore, exercise can be used as a behavioral adjuvant to improve the vaccine efficacy in the elderly.

Metabolomic profiling of maternal plasma identifies inverse associations of acetate and urea with anti-SARS-CoV-2 antibody titers following COVID-19 vaccination during pregnancy.

We conducted a comprehensive metabolomic analysis of plasma samples obtained from pregnant women who displayed varying post-vaccination antibody titers after receiving mRNA-1273-SARS-CoV-2 vaccines. The study involved 62 pregnant women, all of whom had been vaccinated after reaching 24weeks of gestation. To quantify post-vaccination plasma antibody titers, we employed binding antibody units (BAU) in accordance with the World Health Organization International Standard. Subsequently, we classified the study participants into three distinct BAU/mL categories: those with high titers (above 2000), medium titers (ranging from 1000 to 2000), and low titers (below 1000). Plasma metabolomic profiling was conducted using 1H nuclear magnetic resonance spectroscopy, and the obtained data were correlated with the categorized antibody titers. Notably, in pregnant women exhibiting elevated anti-SARS-CoV-2 antibody titers, reduced plasma concentrations of acetate and urea were observed. A significant negative correlation between these compounds and antibody titers was also evident. An analysis of metabolomics pathways revealed significant inverse associations between antibody titers and four distinct amino acid metabolic pathways: (1) biosynthesis of phenylalanine, tyrosine, and tryptophan; (2) biosynthesis of valine, leucine, and isoleucine; (3) phenylalanine metabolism; and (4) degradation of valine, leucine, and isoleucine. Additionally, an association between the synthesis and degradation pathways of ketone bodies was evident. In conclusion, we identified different metabolic pathways that underlie the diverse humoral responses triggered by COVID-19 mRNA vaccines during pregnancy. Our data hold significant implications for refining COVID-19 vaccination approaches in expectant mothers. KEY MESSAGES : Anti-SARS-CoV-2 antibody titers decline as the number of days since COVID-19 vaccination increases. Anti-SARS-CoV-2 antibody titers are inversely associated with acetate, a microbial-derived metabolite, and urea. Amino acid metabolism is significantly associated with SARS-CoV-2 antibody titers.

Seroprevalence, and Risk Factors of Post-Vaccination Antibodies for Foot and Mouth Disease in Tanah Laut District, South Borneo in 2022-2023

&lt;p&gt;Foot and Mouth Disease (FMD) caused by the Foot Mouth Disease virus (FMDV) is an animal disease that spreads quickly and causes huge economic losses. The Indonesian government has established the vaccination program as a form of national FMD management in 2022. This study was conducted to determine the success and post-vaccination seroprevalence of FMD in Tanah Laut District, South Borneo, and to analyze the factors that influence the success of vaccination. The research method is observational analytic with a cross-sectional study approach. Samples were sera of cows and goats that had been vaccinated, then tested serologically with SP ELISA serotype O and NSP ELISA. Result analyzed by chi-square test (X2), odds ratio (OR), relative risk (RR), and spatial analysis (average nearest neighbor).The seroprevalence of immunity to FMD in Tanah Laut Regency was 95.94%. Factors that influence the formation of antibodies after FMD vaccination were the type of animal (OR = 3.781), age (OR = 6.106), sex (OR = 2.801), rearing system (OR = 3.848), feed (OR = 3.448), type of vaccine (OR = 5.508), and number of vaccinations (OR = 0.109). Spatial analysis shows a clustered pattern (Nearest Neighbor Ratio = 0.005457). The seroprevalence of immunity to FMD in Tanah Laut Regency was 95.94%. Goat immune seroprevalence has a higher value when compared to cattle. Factors that influence the formation of FMD vaccination antibodies are animal type, age, sex, feed, rearing system, type of vaccine, and number of vaccinations.&lt;/p&gt;

Factors impacting antibody kinetics, including fever and vaccination intervals, in SARS-CoV-2-naïve adults receiving the first four mRNA COVID-19 vaccine doses

To evaluate the antibody response following the initial four doses of mRNA vaccines (BNT162b2 or mRNA-1273) in SARS-CoV-2-naïve healthy adults and investigate factors influencing antibody titer increases, this prospective cohort study was conducted in Japan from March 2021. The study included participants who received either the 1st and 2nd doses (n = 467), 3rd dose (n = 157), or 4th dose (n = 89). Blood samples were collected before and up to 6 months after each dose, and anti-receptor-binding domain antibody levels were measured. Multivariate analysis (usin multiple linear regression or linear mixed models) revealed several factors significantly associated with higher post-vaccination antibody levels, including mRNA-1273 vaccine (after the 1st and 2nd dose), male gender (after the 3rd and 4th doses), younger age (after the 1st and 2nd dose), non-smoking status (after the 2nd dose), non-use of immunosuppressive agents (after the 1st dose), higher pre-vaccination antibody titers (after the 2nd, 3rd, and 4th doses), and higher post-vaccination fever (after the 2nd and 4th doses). Furthermore, longer intervals since the last dose were significantly associated with higher antibody levels after the 3rd and 4th doses. These findings provide valuable insights for optimizing vaccination strategies.

Longitudinal antibody dynamics after COVID-19 vaccine boosters based on prior infection status and booster doses

Global concern over COVID-19 vaccine distribution disparities highlights the need for strategic booster shots. We explored longitudinal antibody responses post-booster during the Omicron wave in a Japanese cohort, emphasizing prior infection and booster doses. This prospective cohort study included 1763 participants aged 18 years and older with at least three vaccine doses (7376 datapoints). Antibody levels were measured every 2 months. We modeled temporal declines in antibody levels after COVID-19 vaccine boosters according to prior infection status and booster doses using a Bayesian linear mixed-effects interval-censored model, considering age, sex, underlying conditions, and lifestyle. Prior infection enhanced post-booster immunity (posterior median 0.346, 95% credible interval [CrI] 0.335–0.355), maintaining antibody levels (posterior median 0.021; 95% CrI 0.019–0.023) over 1 year, in contrast to uninfected individuals whose levels had waned by 8 months post-vaccination. Each additional booster was correlated with higher baseline antibody levels and slower declines, comparing after the third dose. Female sex, older age, immunosuppressive status, and smoking history were associated with lower baseline post-vaccination antibodies, but not associated with decline rates except for older age in the main model. Prior infection status and tailored, efficient, personalized booster strategies are crucial, considering sex, age, health conditions, and lifestyle.

CHARTING IMMUNE DEFENSE: ANALYZING ANTI-SARS-COV-2 SPIKE ANTIBODY LEVELS POST SPUTNIK V VACCINATION IN PAKISTAN

Rapid ramp up of immune responses against SARS-CoV-2 during pandemic enables adequate prevention and treatment for COVID-19. Estimating levels of SARS-CoV-2 spike protein antibodies post vaccination is crucial for designing mass-vaccination strategies. The aim of this study was to evaluate effectiveness of Sputnik V first dose in Pakistan. A cross-sectional study of 1000 participants was conducted for examining Gam-COVID-Vac or Sputnik V first dose effects at 21st days post administration at Islamabad Diagnostic Center, Islamabad, Pakistan. From 1000 real-time PCR negative (SARS-CoV-2 RNA) individuals, samples were collected and analyzed for antibodies to the SARS-CoV-2 spike protein using Electro-chemiluminescence immunoassay (ECLIA) (Elecsys # 09289267190 Roche, USA). 85% of the participants showed strong positive results with SARS-CoV-2 spike protein antibodies &gt;1.5 AU/ml. The individuals with antibody titer &gt;250 AU/ml were 34.9%. While participants with &gt;100 AU/ml of antibodies were 12.7%. However 9.5% showed antibody titer of &gt;25 AU/ml. 27% of participants had antibody titers of &gt;1.5-2.5 AU/ml. While antibody titers of &lt;1.5 AU/ml were observed among 15.9% of participants. Majority of the individuals represented significantly strong antibody titers against SARS-CoV-2 even before second booster dose of Ad5 based Sputnik V vaccine. Continuous monitoring of antibody levels among COVID-19 vaccinated populations are deemed to assess humoral immunity status against SARS-CoV-2 infections.

Immunogenicity and safety of concomitant bivalent COVID-19 and quadrivalent influenza vaccination: implications of immune imprinting and interference

ObjectivesConcomitant COVID-19 and influenza vaccination would be an efficient strategy. Although the co-administration of monovalent COVID-19 and influenza vaccinations showed acceptable immunogenicity, it remains unknown whether the bivalent COVID-19 vaccine could intensify immune interference. We aimed to evaluate the immunogenicity and safety of concomitant BA.5-based bivalent COVID-19 and influenza vaccination. MethodsAn open-label, nonrandomized clinical trial was conducted for 154 age-matched and sex-matched healthy adults between October 2022 and December 2022. Participants received either a concomitant bivalent COVID-19 mRNA booster and quadrivalent influenza vaccination (group C) or separate vaccinations (group S) at least 4 weeks apart. Solicited and unsolicited adverse events were reported up to 6 months postvaccination. Immunogenicity was evaluated by anti-spike (S) IgG electrochemiluminescence immunoassay, focus reduction neutralization test, and hemagglutination inhibition assay. ResultsGroup C did not meet the noninferiority criteria for the seroconversion rates of anti-S IgG and neutralizing antibodies against the wild-type SARS-CoV-2 strain compared with group S (44.2% vs. 46.8%, difference of −2.6% [95% CI, −18 to 13.4]; 44.2% vs. 57.1%, difference of −13.0% [95% CI to −28.9 to 2.9]). However, group C showed a stronger postvaccination neutralizing antibody response against Omicron BA.5 (72.7% vs. 64.9%). Postvaccination geometric mean titers for SARS-CoV-2 and influenza strains were similar between groups, except for influenza B/Victoria. Most adverse events were mild and comparable between the study groups. DiscussionConcomitant administration of bivalent COVID-19 mRNA and quadrivalent influenza vaccines showed tolerable safety profiles and sufficient immunogenicity, particularly attenuating immune imprinting induced by previous ancestral vaccine strains.

Autogenic splenic implantation versus splenectomy in patients undergoing distal pancreatectomy for benign or low-grade malignant lesions of the distal pancreas: study protocol for a multicentre, open-label, randomized controlled trial (RESTORE)

BackgroundThe spleen plays a significant role in the clearance of circulating microorganisms. Sequelae of splenectomy, especially immunodeficiency, can have a deleterious effect on a patient’s health and even lead to death. Hence, splenectomy should be avoided and spleen preservation during elective surgery has become a treatment goal. However, this cannot be achieved in every patient due to intraoperative technical difficulties or oncological reasons. Autogenic splenic implantation (ASI) is currently the only possible way to preserve splenic function when a splenectomy is necessary. Experience largely stems from trauma patients with a splenic rupture. Splenic immune function can be measured by the body’s clearing capacity of encapsulated bacteria. The aim of this study is to assess the splenic immune function after ASI was performed during minimally invasive (laparoscopic or robotic) distal pancreatectomy with splenectomy.MethodsThis is the protocol for a multicentre, randomized, open-labelled trial. Thirty participants with benign or low-grade malignant lesions of the distal pancreas requiring minimally invasive distal pancreatectomy and splenectomy will be allocated to either additional intraoperative ASI (intervention) or no further intervention (control). An additional 15 patients who will undergo spleen-preserving distal pancreatectomy serve as the control group with normal splenic function. Six months postoperatively, after assumed restoration of splenic function, patients will be given a Salmonella typhi (Typhim Vi™) vaccine. The Salmonella typhi vaccine is a polysaccharide vaccine. The specific antibody titres immediately before and 4 to 6 weeks after vaccination will be measured. The ratio between pre- and post-vaccination antibody count is the primary outcome measure and secondary outcome measures include intraoperative details, length of hospital stay, 30-day mortality and morbidity.DiscussionThis study will investigate the splenic immune function of patients who undergo ASI during minimally invasive distal pancreatectomy with splenectomy. The splenic immune function will be measured using the surrogate outcome of specific antibody titre after vaccination with a Salmonella typhi vaccine. The results will reveal details about splenic function after ASI and guide further treatment options for patients when a splenectomy cannot be avoided. It might eventually lead to a new standard of care making sometimes more demanding and time-consuming spleen-preserving procedures redundant.Trial registrationInternational Standard Randomized Controlled Trials Number (ISRCTN) ISRCTN10171587. Prospectively registered on 18 February 2019.

Absolute concentration estimation of COVID-19 convalescent and post-vaccination IgG antibodies.

Soon after commencement of the SARS-CoV-2 disease outbreak of 2019 (COVID-19), it became evident that the receptor-binding domain of the viral spike protein is the target of neutralizing antibodies that comprise a critical element of protective immunity to the virus. This study addresses the relative lack of information regarding actual antibody concentrations and binding affinities in convalescent plasma (CP) samples from COVID-19 patients and extends these analyses to post-vaccination (PV) samples to estimate protective IgG antibody (Ab) levels. A direct enzyme-linked immunosorbent assay (ELISA) was used to measure IgG anti-spike protein (SP) antibodies (Abs) relative to human chimeric spike S1 Ab standards. Microplate wells were coated with recombinant SP. Affinities of Ab binding to SP were determined by previously described methods. Binding affinities were also determined in an RBD-specific sandwich ELISA. Two indices of protective immunity were determined as permutations of Ab molar concentration divided by affinity as dissociation constant (KD). The range and geometric means of Ab concentrations in 21 CP and 21 PV samples were similar and a protective Ab level of 7.5 μg/ml was determined for the latter population, based on 95% of the normal distribution of the PV population. A population (n = 21) of plasma samples from individuals receiving only one vaccination with the BNT162b2 or mRNA-1273 vaccines (PtV) exhibited a geometric mean Ab concentration significantly (p < 0.03) lower than the PV population. The results of this study have implications for future vaccine development, projection of protective efficacy duration, and understanding of the immune response to SARS-CoV-2 infection.

Comparative characteristics of immune-enzymatic systems for post vaccinal antibodies determination to three infection diseases

Comparative characteristics of immune-enzymatic systems for post vaccinal antibodies determination to three infection diseases