Post-vaccination Immune Response Research Articles

Assessment of humoral immunity to the measles virus in healthcare workers

BACKGROUND: measles is an anthroponotic viral disease characterized by high contagiousness. In the early 2000s in the Russian Federation, the infection was on the verge of elimination, but outbreaks in 2003, 2014, 2019 and the rise in incidence since 2022 refutes this situation. Cleanup vaccination of risk groups and revaccination of persons vaccinated once are ongoing. It is relevant to determine antibodies in blood serum in the vaccinated population and in persons with an unknown vaccination and post-infection history. AIM: of the study is to present the results of a study of humoral immunity to the measles virus in healthcare workers vaccinated against measles and with an unknown vaccination and post-infectious history. MATERIALS AND METHODS: the study was conducted in Kazan, Republic of Tatarstan. The study involved employees of a skin and venereal disease clinic, children's clinics, and a blood center in the amount of 133 people (including 2 men), who were vaccinated and revaccinated with live measles vaccine, after which a sufficient amount of time had passed for the formation of an immune response - 3-4 weeks, as well as 40 female employees with an unknown vaccination and post-infection history. Specific IgG to the measles virus was determined in the test blood sera using the enzyme immunoassay method using the Vector-Best kit (Novosibirsk, Russia). Statistical analysis was carried out using the StatTech v.4.1.9 program (developed by Stattech LLC, Russia). RESULTS. The study was conducted in Kazan, Republic of Tatarstan. The study involved employees of a skin and venereal disease clinic, children's clinics, and a blood center in the amount of 133 people (including 2 men), who were vaccinated and revaccinated with live measles vaccine, after which a sufficient amount of time had passed for the formation of an immune response - 3-4 weeks, as well as 40 female employees with an unknown vaccination and post-infection history. Specific IgG to the measles virus was determined in the test blood sera using the enzyme immunoassay method using the Vector-Best kit (Novosibirsk, Russia). Statistical analysis was carried out using the StatTech v.4.1.9 program (developed by Stattech LLC, Russia). CONCLUSIONS. The ongoing outbreaks of measles in 2003, 2014, 2019, 2022-2023 require constant monitoring of the epidemiological situation with the study of the post-vaccination immune response in vaccinated people and the post-infection response in people with an unknown history of measles

Inserting CTL Epitopes of the Viral Nucleoprotein to Improve Immunogenicity and Protective Efficacy of Recombinant Protein against Influenza A Virus.

Conserved influenza virus proteins, such as the hemagglutinin stem domain (HA2), nucleoprotein (NP), and matrix protein (M), are the main targets in the development of universal influenza vaccines. Previously, we constructed a recombinant vaccine protein Flg-HA2-2-4M2ehs containing the extracellular domain of the M2 protein (M2e) and the aa76-130 sequence of the second HA subunit as target antigens. It demonstrated immunogenicity and broad protection against influenza A viruses after intranasal and parenteral administration. This study shows that CD8+ epitopes of NP, inserted into a flagellin-fused protein carrying M2e and HA2, affect the post-vaccination immune humoral response to virus antigens without reducing protection. No differences were found between the two proteins in their ability to stimulate the formation of follicular Th in the spleen, which may contribute to a long-lasting antigen-specific humoral response. The data obtained on Balb/c mice suggest that the insertion of CTL NP epitopes into the flagellin-fused protein carrying M2e and HA2 reduces the antibody response to M2e and A/H3N2. In C57Bl6 mice, this stimulates the formation of NP-specific CD8+ Tem and virus-specific mono- and multifunctional CD4+ and CD8+ Tem in the spleen and completely protects mice from influenza virus subtypes A/H1N1pdm09 and A/H3N2.

386. SAFETY AND FEASIBILITY OF PERSONALIZED NEOANTIGEN DC VACCINES IN POSTOPERATIVE ESOPHAGUS SQUAMOUS CELL CARCINOMA: A PHASE 1B TRIAL

Abstract Background Immunotherapy, as a neoadjuvant treatment, currently stands at the forefront of esophageal squamous carcinoma research. Yet, the landscape of post-surgery adjuvant therapy remains largely unexplored, especially for patients who experience inadequate responses or develop resistance to initial immunotherapy. Addressing this gap, we have undertaken a single-center, single-arm, prospective, and exploratory clinical study. This study aims to evaluate the efficacy of a personalized neoantigen-loaded dendritic cell vaccine (Neo-DCVac) as a novel adjuvant treatment in ESCC patients who have previously undergone neoadjuvant immunochemotherapy (nICT). Methods Neo-DCVac was designed and administered to 12 ESCC patients undergoing radical mastectomy post-nICT. Tailored adjuvant therapy was based on tumor immune microenvironment (TIME) analysis, following Lam's Stratified Treatment Strategy. The immunization schedule included five doses at weeks 1, 2, 4, 6, and 8, with bi-monthly boosts during the consolidation phase, sustained over a year. Primary endpoints were safety and post-vaccination immune response. Secondary endpoints included 1- and 2-year overall survival (OS) and progression-free survival. T-cell response to neoantigen peptides was assessed using enzyme-linked immunospot (ELISPOT), flow cytometry, and enzyme-linked immunosorbent asssay (ELISA), alongside single-cell sequencing to explore the vaccine's efficacy mechanism. Results From April 2021 to October 2023, a total of 12 ESCC patients were enrolled. The occurrence of all-grade AEs was 38.5% (5/12), all of grade 1-2, with no dose-limiting toxicities. No treatment interruptions or treatment-related deaths were observed. Till October 27 2023, the median follow-up was 31.2 months. Survival analysis revealed 1-year and 2-year disease-free survival (DFS) and overall survival (OS) rates of 88.3%, 66.7%, and 100.0%, 91.7%, respectively. Patients with diver genes had a longer median DFS (not reached) compared with patients without diver genes (10.8 months, P = 0.001). Post-vaccine immunization, all patients showed a marked increase in peripheral blood T cell subtypes (CD3, CD4, CD8), with significant neoantigen peptide response in 75% (9/12) as evidenced by ELISPOT and ELISA tests. Single-cell sequencing coupled with CoNGA analysis revealed a distinct MAIT cell population, displaying 65 clonotypes and 146 cells with consistent GEX profiles and TCR sequences. GLIPH2 analysis on Neo-Vac immunotherapy patients identified shared peptide-MHC specificities, notably in patient ES0-01, and similar patterns in patients ES0-04 and ES0-07, suggesting T cell expansion and neoantigen-specific responses post-vaccination. Conclusions The neoantigen DC vaccine demonstrated favorable safety and exhibited notable efficacy in ESCC.

Multiparametric analysis of the specific immune response against SARS-CoV-2

Background SARS-CoV-2, which causes COVID-19, has killed more than 7 million people worldwide. Understanding the development of postinfectious and postvaccination immune responses is necessary for effective treatment and the introduction of appropriate antipandemic measures. Objectives We analysed humoral and cell-mediated anti-SARS-CoV-2 immune responses to spike (S), nucleocapsid (N), membrane (M), and open reading frame (O) proteins in individuals collected up to 1.5 years after COVID-19 onset and evaluated immune memory. Methods Peripheral blood mononuclear cells and serum were collected from patients after COVID-19. Sampling was performed in two rounds: 3-6 months after infection and after another year. Most of the patients were vaccinated between samplings. SARS-CoV-2-seronegative donors served as controls. ELISpot assays were used to detect SARS-CoV-2-specific T and B cells using peptide pools (S, NMO) or recombinant proteins (rS, rN), respectively. A CEF peptide pool consisting of selected viral epitopes was applied to assess the antiviral T-cell response. SARS-CoV-2-specific antibodies were detected via ELISA and a surrogate virus neutralisation assay. Results We confirmed that SARS-CoV-2 infection induces the establishment of long-term memory IgG+ B cells and memory T cells. We also found that vaccination enhanced the levels of anti-S memory B and T cells. Multivariate comparison also revealed the benefit of repeated vaccination. Interestingly, the T-cell response to CEF was lower in patients than in controls. Conclusion This study supports the importance of repeated vaccination for enhancing immunity and suggests a possible long-term perturbation of the overall antiviral immune response caused by SARS-CoV-2 infection.

Immunostimulatory and Antibacterial Effects of Cannabis sativa L. Leaves on Broilers.

The aim of this study was to evaluate the effect of dried Cannabis sativa L. leaves as a phytogenic mixture added to broiler feed on CD4+ and CD8+ T lymphocyte subpopulations, Newcastle disease virus (NDV) antibody titres, and the presence of E. coli in faecal samples. The study was conducted on 100 male Ross 308 broilers, divided into four groups of 25 broilers, for a 42-day research period. The groups were housed separately in boxes on a litter of softwood shavings and were fed starter mixture from day 1 to day 21 and finisher mixture from day 22 to day 42. Industrial hemp (C. sativa) was grown in the Crkvina area, Croatia (latitude: 45°18'46.8″ N; longitude: 15°31'30″ E). The hemp leaves were manually separated, sun-dried, and ground to a powder. The mixture offered to the control group did not contain cannabis leaves, whereas the three experimental groups received mixtures containing mixed cannabis leaves in a quantity of 10 g/kg, 20 g/kg, or 30 g/kg (E_10, E_20, and E_30, respectively). The mean NDV antibody level was uniform in all study groups until post-vaccination day 14 and increased comparably with time. The percentage of CD4+ and CD8+ lymphocytes in the peripheral blood subpopulation showed statistically significant differences (p < 0.001) in the E_20 group as compared with the control group and both the E_10 and E_30 groups throughout the study period. As the broiler age increased, the CD4+-to-CD8+ ratios also increased and were statistically significant (p < 0.0001) on day 42 in all experimental groups as compared to the control group. Comparing the control group with the experimental groups indicated that the bacterial count was lower in broiler groups having received feed with the addition of 20 g/kg and 30 g/kg C. sativa leaves. In conclusion, the C. sativa leaves were found to elicit a favourable immunomodulatory effect on cell-mediated and humoral immune responses in broilers via increased CD4+ and CD8+ lymphocyte subpopulations and higher CD4+:CD8+ cell ratios, thus indicating enhanced immune function capacity. In addition, C. sativa leaves may have complementary effects on the broiler post-vaccination immune response, increase broilers' resistance to infectious diseases, reduce the effect of stress associated with vaccination, and improve broiler health and welfare.

Generating prophylactic immunity against arboviruses in vertebrates and invertebrates.

The World Health Organization recently declared a global initiative to control arboviral diseases. These are mainly caused by pathogenic flaviviruses (such as dengue, yellow fever and Zika viruses) and alphaviruses (such as chikungunya and Venezuelan equine encephalitis viruses). Vaccines represent key interventions for these viruses, with licensed human and/or veterinary vaccines being available for several members of both genera. However, a hurdle for the licensing of new vaccines is the epidemic nature of many arboviruses, which presents logistical challenges for phase III efficacy trials. Furthermore, our ability to predict or measure the post-vaccination immune responses that are sufficient for subclinical outcomes post-infection is limited. Given that arboviruses are also subject to control by the immune system of their insect vectors, several approaches are now emerging that aim to augment antiviral immunity in mosquitoes, including Wolbachia infection, transgenic mosquitoes, insect-specific viruses and paratransgenesis. In this Review, we discuss recent advances, current challenges and future prospects in exploiting both vertebrate and invertebrate immune systems for the control of flaviviral and alphaviral diseases.

Dynamics of humoral immunity during natural SARS-CoV-2 infection and/or after vaccination with the ‘Sputnik V’ vaccine

Comprehensive analysis of adaptive immune response to SARS-CoV-2 is critical for epidemiological monitoring, as well as for tracking immune response stages and vaccination strategies. Understanding the differences between immunity formed after COVID-19 infection and vaccine-induced immunity is a specific task within this problem. Moreover, the obvious task is to assess the effect of repeated antigenic stimulation on immunological defense against SARS-CoV-2. The aim of present study was a comparative analysis of humoral immunity (anti-SARS-CoV-2 IgA and IgG) developing after natural infection with SARS-CoV-2 and/or after vaccination with anti-COVID vaccine “Sputnik V”. The study involved 36 volunteers. 21 of them had COVID-19 and were vaccinated 8-10 months later (group 1). In 15 primarily vaccinated persons, previous SARS-CoV-2 infection was excluded by means of regular PCR screening and serological testing (group 2). Results: Intensity of humoral immune response to the primary natural SARS-CoV-2 infection and similar indexes of antiviral adaptive immunity after vaccination with “Sputnik V” vaccine were similar in both groups. However, both maximal values of anti-SARS-CoV-2 IgA and IgG and the rates of post-vaccination humoral immune response differed significantly between the persons who have previously had COVID-19 and those who have not previously been infected with SARS-CoV-2. We’ve got statistically significant differences between two groups of participants using Student’s t test comparing the average maximum IgA levels after vaccination (p &lt; 0.05). For IgG levels, these differences are less pronounced. In the first group, the average maximal values of specific IgA and IgG levels after natural infection with SARS-CoV-2 and after subsequent vaccination differed by more than 2 times. The time intervals for reaching maximal antibody levels after vaccination proved to be significantly shorter in the subjects who had a story of COVID-19, than in persons who did not report a clinical COVID-19 infection. Concerning the terms of arising IgG antibody response after vaccination versus cases of COVID-19 in the first group, we obtained a statistically significant difference by the Student’s t-test (p &lt; 0.05). Hence, the persons with a previous natural COVID-19 infection develop a faster, stronger and more durable response to the “Sputnik V” vaccine than the subjects who had no such infection in their history

Experimental Use of Common Marmosets (Callithrix jacchus) in Preclinical Trials of Antiviral Vaccines.

Common marmoset (Callithrix jacchus, CM) is a New World primate species that is of interest for preclinical trials of immunobiological products. In this study, we describe the approaches to long-term laboratory breeding and maintenance of CMs. We also establish the reference values of the main complete blood count and serum chemistry parameters evaluated during preclinical trials of immunobiological products and describe the histological characteristics of CM lymphoid organs during the development of post-vaccination immune response. We show that CMs bred in laboratory conditions excluding background infectious pathology are a relevant model that allows for a high degree of reliability in characterizing the safety and immunogenicity profile of antiviral vaccines during preclinical trials.

IMMUNE RESPONSE TO VACCINATION IN CHILDREN AND YOUNG PEOPLE WITH INFLAMMATORY BOWEL DISEASE: A 10 YEARS SYSTEMATIC REVIEW

Background: In the past decade, there is a notable uptrend in the incidence of IBD among the pediatric population. The immunosuppressive nature of IBD treatment may compromise the natural immune response, potentially impacting vaccination effectiveness. This study aims to to provide a 10 year systematic review of post vaccination immune response in pediatric IBD patients. Methods: This systematic review adhered to the PRISMA 2020 standards and included full-text English literature published between 2014 and 2024. Exclusion criteria involved editorials, review articles from the same journal, and submissions lacking a DOI. Literature was gathered from online sources such as PubMed and SagePub. Result: Our search in PubMed yielded 156 articles, while SagePub produced 243 articles. Focusing on the year 2014, PubMed had 127 articles, and SagePub had 102. Ultimately we selected 6 papers that met our criteria, 3 from PubMed and 3 from SagePub. Conclusion: This study concludes that the immunogenicity of certain vaccines such as PCV13, PPSV23, and rotavirus were not affected by the IBD, except for cholera. No adverse effect were found directly related to vaccination in pediatric IBD patients.

Algorithm for in silico search of immunodominant epitopes for immunodiagnosis of vaccine-targeted infections

This publication presents an algorithm for selecting immunodominant epitopes that are regions of influenza virus proteins used in vaccination in 2023-2024 for use in immunodiagnostics. Using various remote access programmes, an algorithm for searching for immunodominant epitopes was implemented based on the analysis of the amino acid sequence of virus proteins included in vaccines marketed in the Republic of Belarus. This is a stage before synthesis of peptides for laboratory diagnostics of cellular response of immunity system to virus vaccine. That in the future will allow to use only suitable peptides for diagnostics of postvaccinal immune response. Thus, a different set of peptides allows to detect the response of the immunity system to the surface proteins of viruses from vaccines "Grippol", "Vaxigripp Tetra", "Influvak Tetra" or to other proteins of influenza viruses in case of disease. Which is an additional test after evaluation of the humoral response in the form of neutralising antibodies to haemagglutinin.

The relationship between the indicators of natural antibodies, total immunoglobulins and immunocompetent blood cells of sheep in the process of post-vaccination immune response

Innate immunity plays an important role in protecting the body from pathogenic microorganisms. The significance of its structures in vaccination is currently widely discussed. The purpose of the research was to study the dynamics of immunological parameters during the immune response to various types of vaccines.The paper analyzes the levels of natural antibodies in the blood serum of sheep and considers possible correlations with indicators of innate immunity during the post-vaccination immune response. After blood sampling (background), the animals were immunized with rabies (n=5) and anthrax (n=5) vaccines. On the first day of the immune response in the blood of the sheep of the experimental groups, there was a slight increase in tot- Ig, the number of neutrophils increased, and the number of lymphocytes decreased. It was found that on the seven day the concentration of tot- Ig, which also includes specific antibodies to the antigens of vaccines against rabies and anthrax, increased by 2 times compared to the background values. However, the NAb concentration slightly increased only on the first day of the immune response to the anthrax vaccine. In animals, regardless of the vaccine administered, a negative correlation between the number of lymphocytes and neutrophils was constantly maintained (r= -0.88±0.02). As well as in the control (r= - 0.48), the negative correlation between neutrophils /NAb (r= - 0.52; r= -0.76) remained, which indicates the activation of phagocytes and the synthesis of natural antibodies. On the other hand, a correlation relationship between lymphocytes/NAb was established during the immune response to the vaccine against rabies (r=0.5) and anthrax (r=0.7), and the absence of this relationship in the control (r=0.16), which indicates the reaction of natural antibodies to a foreign antigen. The correlations of lymphocytes /NAb (r=0.7) and lymphocytes/tot- Ig (r=0.8) were higher in the dynamics of the immune response to the anthrax vaccine than to the rabies vaccine (r=0.5). It appears that serum anti- KLH NAbs, which include various Ig isotypes, may re ect innate humoral immune competence.

Respon Vaksinasi ND Ayam IPB D1 yang Dipelihara pada Lingkungan Lahan Kering

Newcastle Disease (ND) is one of the diseases that causes large losses in the poultry farming industry. Vaccination can reduce symptoms and protect chickens from ND. High maintenance temperatures on dry land can interfere with immune cell production. IPB D1 chicken is a chicken resulting from a cross between local chickens and purebred chickens that is resistant to disease. The aim of the research was to determine the response of IPB D1 chicken vaccination against Newcastle Disease (ND) and compare the antibody titers of IPB D1 chickens in tropical regions that were vaccinated with ND via the drinking water and intramuscular routes. This research was carried out on 30 IPB D1 chickens divided into three groups, namely , group A vaccination via drinking water, group B vaccination via intramuscular and control group (C) with the aim of comparing the antibody titers of IPB D1 chickens vaccinated via drinking water and intramuscularly and to determine the response of vaccination of IPB D1 chickens against Newcastle Disease. Pre- and post-vaccination immune responses were tested using hemagglutination inhibition (HI). The results showed that the group of chickens vaccinated through drinking water had an average pre-vaccination antibody titer of 1.8 ± 0.91 log 2, at week 2 post-vaccination it was 3.3 ± 2.05 log 2, at week 4 post-vaccination it was 5 .3 ± 2.31 log 2 and at the 8th week post-vaccination 3.2 ± 1.22 log 2. The average antibody titer in the group of chickens vaccinated via intramuscular pre-vaccination was 1.6 ± 0.51 log 2, at week 2. -2 post-vaccination 5.4 ± 3.09 log 2, at the 4th week post-vaccination 4.89 ± 2.71 log 2 and at the 8th week post-vaccination 3.56 ± 2.01. It was concluded that ND vaccination via the drinking water and intramuscular route was able to increase antibodies to reach an average titer above 4 HI log 2 within a period of at least four weeks after administering the vaccine to IPB D1 chickens kept in a dry land environment. The antibody titer of IPB D1 chickens vaccinated intramuscularly increased faster than those vaccinated through drinking water.

Relationships between Parameters for Natural Antibodies, General Immunoglobulins, and Immunocompetent Blood Cells in Sheep in Postvaccination Immune Response

Relationships between Parameters for Natural Antibodies, General Immunoglobulins, and Immunocompetent Blood Cells in Sheep in Postvaccination Immune Response

Dynamics of the postvaccinal humoral immune response in canids vaccinated against CDV

Canine distemper disease, a viral disease that affects canids, domestic and wild, regardless of age, race and sex, is one of the frequent infectious diseases in this species, evolving seriously, with a fatal outcome. Vaccination schemes practiced in companion canids also include vaccination against this infection produced by the canine distemper virus (CDV). This study aims to monitor the titer of anti-CDV antibodies after vaccination, in order to evaluate the efficiency of post-vaccination immune response.

Multivariate analysis of the parameters of the immune response after immunization with inactivated influenza vaccines

Influenza A and B viruses are widely spread respiratory pathogens of humans and cause both isolated cases and local outbreaks of the disease, as well as massive seasonal epidemics and pandemics. Vaccination is the main strategy for combating influenza, and an increase in the proportion of vaccinated people in the population determines the success of vaccination. To identify patterns of postvaccination immune response formation to different types of vaccines and assess the significance of its multiple parameters the appropriate statistical methods should by applied. These methods allow to operate with large datasets and reduce their dimension, while keeping the maximum of information about the differences between individual observations. The aim of our study was the analysis of parameters of humoral and cellular immunity and their dynamics after vaccination with different types of inactivated influenza vaccines (IIV) using statistical methods of complex data analysis. The study was conducted in the clinical department of the Smorodintsev Research Institute of Influenza, Ministry of Health of the Russian Federation, in the flu season 2018 – 2019. The multivariate analysis of the immune response parameters after immunization with IIV “Grippol plus”, “Sovigripp” “Ultrix” included data obtained for 39 volunteers before vaccination, on the 7th and 21st days after vaccination. To identify parameters with significant differences between groups, one-factor analysis of variance (ANOVA) was used separately for each parameter and time point. To visualize the differences in the parameters selected in the analysis of variance, the Principal component analysis (PCA) method was used. The conducted studies revealed the peculiarities of the formation of a post-vaccination immune response to various types of IIV. It was shown that the factors of antigen-specific CD4+ and CD8+ T-cell immune response introduced the major contribution to the formation of the differences between groups. The approach is a powerful tool in analyzing the parameters of the immune response in clinical trials of influenza vaccines and other preventive medicine.

COVID-19 anti immunoglobulin G antibodies serum levels among health care workers post COVID -19 vaccination: A single center study

Coronavirus disease 2019 (COVID-19) pandemic has urged the scientific community internationally to find answers in terms of therapeutics and vaccines to control the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The post vaccination immune response differs between individuals especially health care workers who are the first line of defense to combat this disease. Our aim was to measure levels of anti-IgG antibodies titer post COVID-19 vaccination among health care workers in Suez Canal University Hospital. The study included 141 healthcare workers. Of these, 54 were physicians, 80 nurses, 6 health service workers, and one security guard. We used the Roche Elecsys Anti-SARS-CoV-2 assay for serological detection of IgG. Seropositive was found in 96.5% of the participants, and 43.3% of them had evidence of the prior history of COVID-19 infection. The highest titers of IgG in sera were found in the youngest age groups (20 – &lt;35) years with a mean of 335.1 U/ ml. Participants who received the Sinovac vaccine had the highest mean IgG titer, 354.6U/ml; followed by Sinopharm (mean 352.15 U/ml) then Pfizer and Moderna (311.7U/ml) and AstraZeneca vaccine had the least mean level (267.31U/ml). Fatigue was the most significant short side effect occurring with 34% of the participants. In conclusion, there was a significant rising in serum IgG titer post-vaccine, and better antibody response in those previously infected with COVID-19. The post-COVID-19 vaccine serum IgG titers were affected by age, prior history of COVID-19 infection, and type of vaccine while short side effects post-vaccination may be affected by age and type of the vaccine.

Postinfectious and Postvaccinal Humoral Immune Response to SARS-CoV-2 in Adults: Qualitative and Quantitative Assessment

Relevance. Serological studies play an important role in assessing the spread of SARS-CoV-2 and formation of post-infection and post-vaccination immune response.The Aims aim of the study was a comparative assessment of seroprevalence and concentration of antibodies to SARS-CoV-2 at 3–6 months after infection or vaccination.Materials &amp; Methods. For the presence of total IgM and IgG antibodies to RBD fragment of the SARS-CoV-2 S protein, the blood sera of 1331 people aged 18-70 years were examined, of which 334 had COVID-19 3–6 months before the study, 305 did not have COVID-19 and were vaccinated (using Sputnik V, Russia, or Sinopharm, PRC) 3–6 months before the study, 692 people were not ill and were not vaccinated. A quantitative assessment of IgG antibodies to the full-size S-protein of SARS-CoV-2 was performed for 435 samples.Results. The proportion of seropositive individuals 3–6 months after COVID-19 or after vaccination did not differ: 92.5% and 93.8% of the corresponding group had antibodies. Among the non-ill and unvaccinated, 45.7% also had specific antibodies, which indicates a high level of asymptomatic infection with SARS-CoV-2. The group of vaccinated was also examined immediately before the introduction of the vaccine, and 39.7% of them already had specific antibodies due to asymptomatic infection with SARS-CoV-2. The median concentration of antibodies in the group of COVID-19 was statistically significantly higher than in asymptomatically infected (50.9 AE/ml versus 29.1 AE/ml). The largest proportion of seropositive individuals (100.0%) and the highest concentration of antibodies (110 AE/ml) were detected in the group of vaccinated who had pre-existing antibodies.Conclusion. Infection with the SARS-CoV-2 is characterized by a high frequency of subclinical course. Asymptomatic infection induced a weaker immune response compared to symptomatic COVID-19 or vaccination. Hybrid immunity caused by natural infection with SARS-CoV-2 and subsequent vaccination was the most persistent and pronounced.

Various reagent kits for comparatively analyzed effectiveness of humoral immune response after vaccination “Sputnik V"

Modern methods of vaccination have confirmed their high effectiveness in fighting against the pandemic of a novel coronavirus infection. However, the use of various types of vaccines requires studying the effectiveness of the post-vaccination immune response (PIO), first of all, assessing the specificity and amount of production of antibodies to the surface and internal antigens of the SARS-CoV-2 virus, in particular, after the use of the most promising domestic vaccine Gam-Covid-Vac (Sputnik V). In particular, the data on the effectiveness of PVIR (increased antibody level) for the most promising domestic vaccine Gam-Covid-Vac (Sputnik V) need to be confirmed. It is also necessary to evaluate the effectiveness of the laboratory methods used for this purpose. To assess the effectiveness of PVIR, samples of biomaterial (blood serum) obtained on the 2225 day after inoculation of the second component of the vaccine from 202 Sputnik V-vaccinated, not preimmunized subjects, lacking antibodies to SARS-CoV-2 before vaccination, were examined. The levels of IgG and IgM antibodies to the surface and nucleocapsid antigens of the SARS-CoV-2 virus were determined using several semi-quantitative and quantitative methods and reagent kits from national and foreign manufacturers. To assess the diagnostic effectiveness of the methods, a comparative analysis of the specificity and sensitivity of all the laboratory methods used and a data correlation for various quantitative methods (using the Spearman correlation coefficient) between antibodies specific to the full-sized trimerized S-protein and the receptor-binding domain (RBD) of the SARS-CoV-2 S-protein were carried out. During the study, it was determined that all the reagent kits used to study IgG antibodies against SARS-CoV-2 S-protein and S-protein RBD showed maximum (100%) specificity in in the majority subjects (from 186 to 202 samples). The relevance of the data (comparative specificity), both for semi-quantitative and quantitative ELISA as well as for both ILA test systems regarding qualitative characteristics (positivenegative) was also close to the maximum magnitude (98.499.4%). A post-vaccination immune response during Sputnik V vaccination analyzing production of specific IgG antibodies was observed in 98.9% of all vaccinated subjects. IgG antibody range was studied to assess related protective level. Data are presented that a protective level of more than 150 BAU/мл was observed in 59.390.5% of the subjects, above 500 BAU/ml in 22.052.4% of the subjects, depending on the method used and the set of reagents. Based on the data obtained, it is concluded that all the methods and kits of reagents used, including domestically manufactured semi-quantitative tests, can be considered adequate to assess effectiveness of the post-vaccination immune response analyzing production of SARS-CoV-2-specific antibodies.

Response to mRNA SARS-CoV-2 vaccination evaluated by B-cell receptor repertoire after tixagevimab/cilgavimab administration.

The use of anti-SARS-CoV-2 antibody products like tixagevimab/cilgavimab represents an important strategy to protect immunocompromised patients with haematological malignancies from COVID-19. Although patients who receive these agents should still be vaccinated, the use of tixagevimab/cilgavimab can mask the production of anti-spike antibody after vaccination, making it hard to assess vaccine response. We have newly established a quantification method to assess the response to SARS-CoV-2 vaccination at the mRNA level using B-cell receptor (BCR) repertoire assay and the Coronavirus Antibody Database (CoV-AbDab). Repeated blood samples before and after vaccination were analysed for the BCR repertoire, and BCR sequences were searched in the database. We analysed the number and percentage frequency of matched sequences. We found that the number of matched sequences increased 2 weeks after the first vaccination and quickly decreased. Meanwhile, the number of matched sequences more rapidly increased after the second vaccination. These results show that the postvaccine immune response can be assessed at the mRNA level by analysing the fluctuation in matching sequences. Finally, BCR repertoire analysis with CoV-AbDab clearly demonstrated the response to mRNA SARS-CoV-2 vaccination even after tixagevimab/cilgavimab administration in haematological malignancy patients who underwent allogeneic haematopoietic stem cell transplantation.

Postvaccination immune responses and risk of primary total hip arthroplasty—A population-based cohort study

To investigate the relationship between individual postvaccination immune responses and subsequent risk of total hip arthroplasty (THA) due to idiopathic osteoarthritis (OA) or rheumatoid arthritis (RA). Results of tuberculin skin tests (TSTs) following the Bacille Calmette-Guerin (BCG) vaccination were used as a marker of individual immune responses. TST results from the mandatory mass tuberculosis screening program 1948-1975 (n=236 770) were linked with information on subsequent THA during 1987-2020 from the Norwegian Arthroplasty Register. The multivariable Cox proportional hazardregression was performed. A total of 10 698 individuals received a THA during follow-up. In men, there was no association between TST and risk of THA due to OA (Hazard ratio [HR] 1.01, 95% confidence interval [CI] 0.92-1.12 for positive versus negative TST and HR 1.06, 95% CI 0.95-1.18 for strong positive vs negative TST), while the risk estimates increased with increasingly restrictive sensitivity analyses. In women, there was no association with THA due to OA for positive versus negative TST (HR 0.98, 95% CI 0.92-1.05), while a strong positive TST was associated with reduced risk of THA (HR 0.90, 95% CI 0.84-0.97). No significant associations were observed in the sensitivity analysis for women or for THA due to RA. Our results suggestthat an increased postvaccination immune response is associated with a nonsignificant trend of increased risk of THA among men and a decreased risk among women, although risk estimates were small.