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Background: Serological studies can demonstrate pathogen circulation in regional populations and reflect public health mea-sures' effectiveness during different pandemic phases. By late November 2021, coinciding with the third pandemic wave, the sero-prevalence of SARS-CoV-2 spike IgG antibodies among the Iranian population was 32.63%. Objective(s): This study aimed to assess the Iranian population's seroprevalence during the fifth pandemic wave by analyzing donated blood samples. Method(s): This population-based cross-sectional study was conducted on Iranian blood donors referred to all 31 main provincial capitals between August 2021 and September 2021. The participants selected through quota sampling were asked to complete a questionnaire on socio-demographics and coronavirus disease 2019 (COVID-19)-related information. Also, SARS-CoV-2 spike IgG antibodies were measured in serum samples using SARS-CoV-2 enzyme-linked immunosorbent assay (ELISA) kits. The seroprevalence was weighted based on the gender and age groups of the population and then adjusted for test performance. Result(s): Totally 3,339 blood donors participated in this study. The overall population-weighted seroprevalence adjusted for test performance was 52.67% (95% confidence interval (CI): 50.14-55.21). Seroprevalence was higher among participants with a high school diploma (55.45%, 95% CI 50.61-60.29), a positive history of close contact with COVID-19 patients (65.23%, 95% CI 60.83-69.63), and previous positive COVID-19 PCR tests (86.51%, 95% CI 82.32-90.7). Conclusion(s): More than half of the study population was exposed to SARS-CoV-2, indicating a 1.7-fold increase in the seroprevalence between late November 2020 and mid-September 2021. Our finding illuminated the pattern of Iran's fifth wave of the pandemic.Copyright © 2023, Author(s).
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A clinical analysis of COVID-19 cases combined with acute respiratory diseases is presented. The aim of the study was to analyze clinical and laboratory data of patients with combined COVID-19 infection. In patient A. infected with SARS-CoV-2 without X-ray confirmation of lung damage, acute tonsillitis, polyadenopathy, hepatosplenomegaly, moderate leukocytosis, lymphomonocytosis and the presence of reactive lymphocytes were detected. Serological and molecular biological studies were carried out for the purpose of differential diagnosis. A positive test result for IgM antibodies to EBV was obtained. The method of polymerase chain reaction (PCR) revealed EBV DNA in blood plasma. The result of the determination of heterogeneous IgG antibodies to the EBV caspid antigen is negative. Clinical symptoms of the patient with coronavirus infection COVID-19, confirmed by radiological and serological screening, included: fever, sore throat, hyperemia and hypertrophy of the palatine tonsils, hepatomegaly, changes of the cellular composition of the blood. At the same time, the lymph nodes in the neck, chest and abdominal cavity were not enlarged;the presence of reactive lymphocytes and plasma cells was not detected. Serological markers of EBV were also not detected. A PCR test for Epstein-Barr virus DNA was negative.Copyright © 2022 Infectious Diseases: News, Opinions, Training.
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Background: Patients with cancer are vulnerable to coronavirus disease 2019 (COVID-19). Given the rising number of COVID-19 cases and relaxation of stringent COVID-19 protocols, assessment of the level of protective immunity to COVID-19 in patients with cancer has assumed importance. Objective(s): Our primary objective was to evaluate the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies in patients with cancer. Material(s) and Method(s): We conducted a cross-sectional study on 100 patients with solid tumors attending our Oncology Department at the Believers Church Medical College, Kerala, India, between December 2020 and June 2021. Seroprevalence was assessed using the VITROS Anti-SARS-CoV-2 IgG test (Ortho-Clinical Diagnostics, Rochester, NY, USA). Additionally, we assessed the factors associated with seropositivity and collected data regarding the general experience of patients with cancer during the pandemic. Result(s): The median age of the participants was 62 years (IQR, 53-69.8);52 (52%) were males. The seroprevalence of the SARS-CoV-2 IgG antibodies was 11% (95% CI, 4.8-17.1). Age < 50 years was the only factor that was significantly associated with a higher rate of COVID-19 antibodies (77% vs 8.9% in patients >= 50 years;P = 0.007), and sex, smoking, and the use of alcohol did not show any association. The majority (77/100, 77%) of the patients were worried about contracting COVID-19 infection;some even deferred cancer-directed treatment because of the fear of visiting health care settings. Conclusion(s): Low seroprevalence of SARS-CoV-2 IgG antibodies in unvaccinated patients with cancer is a matter of concern as it indicates that many of these patients are still vulnerable to infection. There is an urgent need to continue implementing strict safety measures in oncology centers and to encourage widespread COVID-19 vaccination to prevent the uncontrolled spread of COVID-19 among patients with cancer. (Funded by the institution, Believers Church Medical College, Kerala).Copyright © 2023 Neurology India, Neurological Society of India Published by Wolters Kluwer - Medknow.
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Introduction In this study, we aimed to monitor anti-spike and anti-nucleocapsid antibodies positivity in healthcare workers (HCWs) vaccinated with two doses of inactivated CoronaVac (Sinovac, China) vaccine. Methods Overall, 242 volunteer HCWs were included. Of the participants, 193 were HCWs without history of prior documented COVID-19 (Group 1), while 49 had history of prior documented COVID-19 before vaccination (Group 2). The participants were followed up for SARS-CoV-2 antibodies positivity at four different blood sampling time points (immediately before the second vaccine dose and at the 1st, 3rd months and 141-150 days after the second dose). We investigated the serum IgG class antibodies against SARS-CoV-2 RBD region and IgG class antibodies against SARS-CoV-2 nucleocapsid antigen by chemiluminescent microparticle immunoassay (CMIA) method using commercial kits. Results We found positive serum anti-RBD IgG antibody in 76.4% of the participants (71% in Group 1;98% in Group 2) 28 days after the first dose. When the antibody levels of the groups were compared at the four blood sampling time points, Group 2 anti-RBD IgG levels were found to be significantly higher than those in Group 1 at all follow-up time points. Although anti-RBD IgG positivity persisted in 95.6% of all participants in the last blood sampling time point, a significant decrease was observed in antibody levels compared to the previous blood sampling time point. Anti-nucleocapsid IgG antibody was positive in 12 (6.2%) of participants in Group 1 and 32 (65.3%) in Group 2 at day 28 after the first dose. At the fourth blood sampling time point, anti-nucleocapsid antibodies were found to be positive in a total of 20 (9.7%) subjects, 10 (6.1%) in Group 1 and 10 (23.8%) in Group 2. Conclusions In this study, it was determined that serum antibody levels decreased in both groups after the third month after the second dose in HCWs vaccinated with CoronaVac vaccine.Copyright © GERMS 2022.
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Objectives: Few studies evaluate the immunogenicity and safety of different COVID-19 vaccine platforms in patients with primary Sjogren's Syndrome (pSS). The present study aims to assess the immunogenicity through anti-spike IgG antibodies after the COVID-19 vaccine dose in heterologous groups compared to homologous regimen in patients with pSS. Method(s): These data are from the SAFER study: 'Safety and efficacy of the COVID-19 vaccine in rheumatic disease', a real-life phase IV multicenter longitudinal study, evaluating patients since before the first dose. Pregnant women, those with a history of serious adverse events prior to any vaccine, and those with other causes of immunosuppression were excluded. Patients with pSS > 18 years, classified according to ACR/EULAR 2016 classification criteria were included. Antibodies against the Receptor Binding Domain - RBD portion of the Spike protein of SARS-CoV-2 (IgG-S) were measured by chemiluminescence (Architect SARS-CoV-2 Quanti II, Abbott), before the first dose and 28 days after the 2nd and 3rd dose. Seropositivity was defined as IgG-Spike titers >=7.1 BAU/mL. Patients received adenoviral vector (ChAdOx1, Astrazeneca), mRNA (Pfizer) or inactivated SARS-COV-2 (Coronavac). Non-parametric methods were used. The alpha level of significance was set at 5%. Result(s): 56 participants received 3 doses, 46 +/- 11 years old, disease duration 7.62 years, 92.9% female, 41.1% White and 55.4% Mixed. The homologous third-booster dose group (n = 15, all ChAdOx1) and heterologous group (n = 41) were homogeneous for age, sex, ethnicity, comorbidities, medication and baseline IgG-S median [IQR] titers. After primary vaccination (2 doses) IgG-S median and titers [IQR] were similar in homologous and heterologous groups (373.03 [179.58, 843.92] vs. 473.36 [119.05, 1059.60], p = 0.705). Third-booster dose induced higher IgG-S median [IQR] titers compared to only 2 doses (1229.54 [333.55, 4365.47] vs 464.95 [140.42, 1015.25], p alpha 0.001). Heterologous 3rd-booster induced higher IgG-S median [IQR] titers than homologous scheme with ChAdOx1 (1779.52 [335.83, 4523.89] vs 730.76 [303.37, 1858.98], p = 0.150), Fig 1 and 2, although not statistically significant. Conclusion(s): Third booster dose induced higher humoral immune response compared to two doses whichmay improve protection against COVID-19 in patients with pSS. Although not statistically significant, the response to the heterologous scheme tended to be better than the response to the homologous booster vaccination, which heterologous booster scheme tended to respond better than homologous booster vaccination, which is relevant in this immunosuppressed population. Increasing the sample size will help clarify this issue. .
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The level and duration of protective immunity are often analyzed qualitatively or semi-quantitatively. The same strategy is applied to the analysis of antibody dynamics. At some point in time t after exposure or immunization, the presence of immunity against the infection is inferred from the level of specific antibodies by comparing it to a reference value. This approach does not account for the stochastic nature of human disease after exposure to a pathogen. At the same time, it is not fully clear what antibody level should be considered protective. The aim of this study was to develop a mathematical model for quantitative determination of protective immunity against SARS-CoV-2 and its duration. We demonstrate that the problem of describing protective immunity in quantitative terms can be broken down into 2 interrelated problems: describing the quantitative characteristics of a pathogen's virulence (in our case, the pathogen is SARS-CoV-2) and describing the dynamics of antibody titers in a biological organism. Below, we provide solutions for these problems and identify parameters of the model which describes such dynamics. Using the proposed model, we offer a theoretical solution to the problem of protective immunity and its duration. We also note that in order to quantitatively determine the studied parameters in a homogenous population group, it is necessary to know 5 parameters of the bivariate probability density function for correlated continuous random variables: the infective dose of the pathogen and the antibody titer at which the disease develops and which are still unknown.Copyright © Extreme Medicine.All right reserved.
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Objectives: Patients with immune-mediated rheumatic diseases (IMRDs) develop more severe outcomes of Coronavirus disease 2019 (COVID-19). Recent studies have contributed to understand the safety and efficacy of COVID-19 vaccines in IMRDs, suggesting that different diseases and therapies may interfere on immunization efficacy. In this study we analyze the immunogenicity of COVID-19 vaccines in patients with Systemic Vasculitides (VASC), the rate of COVID-19 and the frequency of disease relapse following immunization. Method(s): We included patients with VASC (n = 73), a subgroup of the SAFER study (Safety and Efficacy on COVID-19 Vaccine in Rheumatic Disease), a longitudinal, multicenter, Brazilian cohort.We analyzed the geometric means of IgG antibody against receptor-biding domain of protein spike of SARS-CoV-2 (anti-RBD) after two shots of CoronaVac (Inactivated vaccine), ChadOx-1 (AstraZeneca) or BNT162b2 (Pfizer-BioNTech). IgG anti-RBD was measured by chemiluminescence test. We assessed new-onset COVID-19 episodes, adverse events (AE) and disease activity for each VASC. Result(s): The sample included Behcet's disease (BD) (n = 41), Takayasu arteritis (TAK) (n = 15), antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) (n = 14), polyarteritis nodosa (n = 7) and other small vessel VASC(n = 6). The majority of patients were female (69%) without comorbidities (49%) and a median age of 37 years. The most common medication was conventional synthetic disease-modifying anti-rheumatic drugs, followed by biologic drugs. No patient received rituximab at baseline. Most patients received CoronaVac (n = 25) or ChadOx-1 (n = 36), while four received BNT162b2. Baseline IgG-RBD means were 1.34 BAU/mL. They increased to 3.89 and 5.29 BAU/mL after the 1st and 2nd vaccine dose, respectively. ChadOx-1 had higher antibody titers than CoronaVac (p = 0.002). There were no differences between different VASC. There were 3 cases of COVID-19 after immunization with CoronaVac. BD patients had a tendency for more cutaneous-articular activity following ChadOx-1. There were no severe relapses and no serious adverse events. Conclusion(s): Our results show the safety of different SARS-CoV-2 vaccines in VASC population. A progressive increase of IgG-RBD antibodies was observed after each dose. ChadOx-1 led to higher IgG-RBDgeometricmeans compared toCoronaVac. Finally, even though ChadOx-1 presented a tendency of triggering mild disease activity, there were no significant disease activity following vaccination in VASC patients. .
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Intro: Different vaccines against COVID-19 have been approved by the World Health Organization (WHO) at different stages, however, limited data is available on long-term kinetics of antibodies induced by vaccines. This study was performed to investigate the persistence and dynamicity of BBV-152 (Covaxin)- and AZD1222 (Covishield)-induced immunoglobulin-G (IgG) antibodies over the year and neutralizing antibodies' status after the one-month post booster dose. Method(s): This 52-week longitudinal cohort study documented antibody persistence and neutralizing antibody status among 278 health-care workers (HCWs) from four different healthcare and research facilities in Odisha, enrolled in January 2021 and continued until March 2022. An automated chemiluminescence immune assay (CLIA) platform from Abbott Diagnostics was used to quantify IgG antibodies against SARS-CoV-2's spike receptor-binding domain (RBD) and a surrogate virus neutralization test (sVNT) was performed by enzyme-linked immunosorbent assay (ELISA). If any participants developed any symptoms of COVID-19, nasopharyngeal swabs were collected and sent to ICMR- RMRC, Bhubaneswar for RT-PCR confirmation. Finding(s): Among the 243 participants, 119 HCWs (48.97%) were Covaxin recipients and the remaining 124 (51.02%) were Covishield recipients. During the seven follow- ups, 104 participants (42.79%) were identified as vaccine breakthrough cases. In 139 non-infected HCWs, the median antibody titer significantly waned after ten months of double dose, both for Covaxin (342.7 AU/mL at DD1 vs 43.9 AU/mL at DD10) and Covishield (2325.8 AU/mL at DD3 vs 595.2 AU/mL at DD10). No statistically significant differences in antibody titers were observed based on age, gender, comorbidities, and blood groups. The median inhibition activity of sVNT was increased significantly for Covaxin and Covishield booster recipients. Among the booster dose recipients, 24 had breakthrough cases by the Omicron variant. Conclusion(s): Results of this longitudinal cohort study can be used to implement vaccination strategies and could also aid in tracking and designing vaccine mandates to minimize vaccine escape.Copyright © 2023
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Patients with end-stage chronic kidney disease treated with hemodialysis are at risk of infection and severe course of the new coronavirus infection. This opinion was based on the data obtained as a result of PCR testing during the active phase of the disease with detailed clinical symptoms. However, this diagnostic method does not allow one to fully assess the prevalence of infection in the population. The aim - studying of the frequency of SARS-CoV-2 infection in patients receiving hemodialysis treatment and the spectrum of antiviral antibodies, depending on the nature of the course of COVID-19. Material and methods. 100 patients with chronic kidney disease (stage 5D) treated at the outpatient Dialysis Center (MCVTP) were included in the study by a simple random sample. The assessment of SARS-CoV-2 infection was carried out by analyzing the material of smears obtained from the naso-oropharynx by PCR and blood serum samples by ELISA. The study excluded 14 patients with dubious results for the determination of serological markers SARS-CoV-2 and 1 patient with active infection, who was isolated from the RNA of the virus. Results. IgM and IgG antibodies were detected in 49 (57.6%) of the 85 examined patients. 24 of them (group 1) were diagnosed with COVID-19 infection with typical clinical symptoms 3-9 months ago, and 25 (group 2) had no clinical manifestations of the acute respiratory infection at the appropriate time suggesting an asymptomatic course of the disease. IgM class antibodies were detected with equal frequency in group 1 and in group 2 (33.3 vs 24.0%, respectively, p<0.6). IgG antibodies exclusively to the nucleocapsid N-protein (IgGn) were detected only in the latent form of the disease (32%), while antibodies against the S-protein (spike protein) of the virus (IgGs and IgGn+s) were detected more often in the manifest form compared to the asymptomatic one (100 vs 60%, respectively, p<0.05). Conclusion. In a random cohort of patient receiving hemodialysis treatment, more than half were asymptomatic.Despite a wide range of prevention measures, SARS-CoV-2 infection among patients treated with hemodialysis is more than 2 times higher than in the general population.Copyright © 2021 Geotar Media Publishing Group. All rights reserved.
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Aim. An online survey among social network users was conducted to assess the frequency of COVID-19 cases, the spectrum of medications used for treatment, and the subjective assessment of clinical manifestations of the disease. Material and methods. An anonymous online survey was conducted among users of various social networks using a questionnaire created on the SurveyMonkey survey and research platform. During the first month of December 2021, the survey included 23 questions regarding the clinical and demographic characteristics of respondents, the number of COVID-19 cases, clinical manifestations, and severity, as well as the need for medical help and medication. Results. 752 respondents took part in the online survey, more than 70% of them are under 50 years old. Among the respondents 59.73% had a new coronavirus infection (COVID-19). More than 40% of the participants had COVID-19 in the period from September 2020 to April 2021 (2nd wave in Russia). In 79.2% of people, the presence of a new coronavirus infection was confirmed by one of the diagnostic methods: polymerase chain reaction (PCR test), radiography, the presence of antibodies to Ig G/M, and took into account the presence of contact with infected SARS-CoV-2. 411 participants observed any clinical manifestations of the disease. Most often respondents who had COVID-19 indicated weakness, cough, dyspnea, disappearance or decrease in the acuity of smell and taste. The volume of lung tissue damage in 36.5% of cases was less than 25%. The disappearance of any clinical manifestations of the disease immediately after recovery was noted by 32.0% of respondents. Most of the patients (59.2%) sought medical help at the polyclinic, 38.9% had to self-medicate. 71.9% respondents indicated they had been vaccinated against COVID-19, but without specifying the timing and completeness of the course. Side effects after immunization (fever, weakness, soreness, and redness at the injection site) were subjectively assessed by 41.9% of respondents. Conclusion. Among the surveyed respondents, 62.7% of the disease symptoms were mild. The highest number of cases occurred in the 2nd and 4th waves of COVID-19 morbidity in Russia. Most often respondents indicated symptoms of acute respiratory infection. The complete disappearance of clinical manifestations of the disease immediately after recovery was noted by 32.0 % of respondents, and the persistence of symptoms for up to a year - 7.5. More than 70% of the participants in the online survey reported vaccination against COVID-19, but the questionnaire did not include questions about the timing of vaccinations (before or after COVID-19) and the completeness of the course.Copyright © Eco-Vector, 2023. All rights reserved.
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Objectives: To evaluate the immunogenicity of ChAdOx1, Coronavac and BNT162B2 vaccines in SLE patients, including homologous and heterologous immunizations. Method(s): The 'Safety and efficacy on COVID-19 Vaccine in Rheumatic Disease-SAFER study' is a Brazilian multicentric longitudinal phase IV study to evaluate COVID-19 Vaccine in immune-mediated rheumatic diseases (IMRD) in real life, started on May 2021. SLE patients (according to the 2012 SLICC classification criteria), older than 18 years of age were recruited after 2 or 3 doses of vaccine against COVID-19 (ChAdOx1, BNT162b2 and CoronaVac) and were evaluated at baseline and on the 28th day after each dose. Homologous immunization was considered if they received three doses of the same vaccine and heterologous if a different one was applied. IgG antibody against SARS-CoV-2 spike receptor-binding domain were measured by chemiluminescence (SARS-CoV-2-IgG-II Quant assay, Abbott-Laboratories) at baseline and 28 days after the first, 2nd and 3rd doses (Seropositivity IgGSpike>= 7.1BAU/mL). Statistical analysis: ANOVA and pairwise comparisons tests Results: 316 SLE patients were included (255 heterologous and 61 homologous immunization), 89.2% were female and the mean age was 37.6 +/- 11.2 years. The two groups were homogeneous regarding demographical data, disease activity and immunosuppressive treatment. 49.7% used corticosteroids (alpha 5 mg/day in 52.3%), 83.5% antimalarials, 22.8% azathioprine and 20.3% mycophenolate mofetil. 207 patients received the first two doses with CoronaVac, 128 ChadOx-1 and 32 BNT162b2. Regarding the first two doses of the same vaccine, there was no difference in IgG titers over time between CoronaVac or ChadOx-1 (p = 0.313). IgG titers increased in all vaccine groups, with difference only after 2nd dose: 4.96 +/- 1.71BAU/mL CoronaVac vs. 6.00 +/- 1.99BAU/mL ChadOx-1 vs. 7.31 +/- 1.49BAU/mL BNT162b2 (p alpha 0.001). There was no difference in IgG titers over time between homologous or heterologous vaccine schedule (p = 0.872). IgG titers also increased in all groups, with difference only after 2nd dose: 5.49 +/- 1.96BAU/mL heterologous vs. 6.30 +/- 2.10BAU/mL homologous (p = 0.009). Conclusion(s): Induction of immunogenicity occurred in different vaccine regimens in SLE patients. Future research to explore different heterologous schemes in IMRD must be performed.
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The problem of the incidence of new coronavirus infection in childhood is becoming increasingly important. At the same time, questions arise regarding the peculiarities of the pathogenesis of COVID-19 in children. The aim of the research was to study the clinical and immunological features of COVID-19 in children hospitalized with a severe course of the disease. Material and methods. We examined 53 children from 0 to 15 years old, hospitalized with suspected new coronavirus infection at Children's Clinical Hospital No. 3 in Novosibirsk from October to December 2020. Determination of specific IgM and IgG antibodies to SARS-CoV-2 antigens in serum blood was carried out using the ELISA method. SARS-CoV-2 virus RNA in nasopharyngeal and oropharyngeal swabs was determined using commercial kits for PCR diagnostics. A z-test was used to compare relative numbers. The significance level was taken equal to 5% (p=0.05). Results and discussion. All examined children hospitalized with suspected COVID-19, regardless of the duration of the disease, had specific IgG antibodies to SARS-CoV-2 antigens, which confirms earlier contact with the new coronavirus in relation to the time of the examination. In 63.6% of cases, specific IgM antibodies of the class to SARS-CoV-2 were detected in the blood serum, in 6% of cases the result was doubtful. IgM antibodies were not detected in blood serum in 30.3% of patients. The results obtained for the determination of IgG and IgM antibodies to SARS-CoV-2 antigens may reflect the atypical nature of seroconversion in COVID-19. An extremely diverse clinical symptomatology was revealed, including, in addition to catarrhal syndrome and intoxication syndrome, abdominal, meningeal, and articular syndromes. In 24.3% of children, polymorphic exanthema was detected, which may be a manifestation of the systemic nature of damage to the vascular wall. Conclusion. With serologically confirmed SARS-CoV-2 etiology of the infectious process in the examined children, an extremely diverse clinical symptomatology was revealed, which, most likely, may be associated with multiple organ damage.Copyright © Transplantologiya. The Russian Journal of Transplantation.All right reserved.
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*Presenting author Emerging infectious diseases have been causing outbreaks in humans for centuries and most infectious diseases originate in animals. Re-emerging zoonotic pathogens are rapidly increasing in prevalence or geographic range and causing a significant and growing threat to global health. The present work provides an insight of zoonotic viruses risk at human-bat/rodent interfaces in Cambodia. We conducted studies to investigate the circulation of zoonotic viruses and the risk of exposure in human living at the interfaces with bats and rodents. Rodent's samples were collected in rural and urban areas of Cambodia. Organs were tested for Hantavirus, Orthohepevirus species C and Arenavirus. Bat's samples were collected in Steung Treng for Sarbecovirus and in Battambang and Kandal for Nipah virus detection. People working/living at the human-animal interfaces were screened for IgG antibodies. In rodents (750), hantavirus was detected in 3.3% rodents from urban areas only. Seoul orthohantavirus was the most predominant virus followed by Thottapalayam virus. HEV-C was detected only in rodents from urban settings (1.8%). Arenavirus was detected in both rural (6.8%) and urban (2.5%) areas. In humans (788), the seroprevalence of IgG antibodies against hantavirus, HEV-A and Arenavirus was 10.0%, 24% and 23.4% respectively. NiV was detected in flying fox's urines collected between 2013-2016 in Kandal (0.63%) and in Battambang (1.03%). Blood samples collected in both provinces were negative for NiV antibodies. SARS-CoV-2 related virus was detected in Rhinolphus shameli in Steung Treng in 2010, 2020 and 2021. Blood samples from people living at the vicinity of positive bats were positive for antibodies against CoV (7.7%), but no specific neutralizing SARS-CoV2 antibodies were detected. Our studies provided insight of the risk of zoonoses in Cambodia and highlighted the importance of zoonotic surveillance and further One Health effort to prevent, detect, and respond to future cross-species transmission.Copyright © 2023
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Intro: Children and Young people were the last group in England be offered COVID-19 vaccination (from September 2021), thus were the largest susceptible group when SARS-CoV-2 Omicron variants emerged. We monitored vaccine and naturally-derived antibodies in schools between November 2021 and March 2022. Method(s): We conducted three large surveys (November 2021, January and March 2022) in a nationally representative random sample of primary and secondary schools, stratified by regions. Oral fluid samples were tested for IgG antibodies against SARS-CoV-2 nucleocapsid (anti-NP) and spike (anti-S1) proteins using novel validated ELISAs;vaccines used in England elicit anti-S1 antibodies only. We calculated weighted prevalences for each survey, and used multilevel logistic regression to investigate associations with socio-demographic factors. Finding(s): Overall 11311 students contributed 22478 biological samples (respectively 4840, 7549 and 10089 in rounds 1, 2 and 3, with similar socio- demographic characteristics). In 4-11 year olds, not eligible for vaccination, anti- S1 and anti-NP antibody prevalences were 31.3% and 26.6%, 46.2% and 43.8%, and 53.4% and 58.7% respectively over the three rounds. The corresponding estimates in 12 to 18 year olds) were 70.7% and 34.6%, 85.6% and 45.9%, 89.0 and 53.9%. In November 2021 (before Omicron dominance), higher anti-S1 antibody positivity was associated with older age and Black ethnicity, and non- eligibility for free school meals in 4-11 year olds. In 12-18 years it was associated with non-eligibility for free school meals. In March 2022 when Omicron dominated, these associations remained, together with urban location in 4-11 years old. Conclusion(s): The steep increase in 4-11 year olds in both sets of antibodies reflected the emergence and spread of highly infectious Omicron variants whilst high and increasing anti-S1 prevalence in secondary students was consistent with greater vaccine uptake. Socioeconomically deprived 12-18 year olds had lower odds of anti-S1, suggesting lower vaccine uptake or access.Copyright © 2023
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Background: High titer COVID-19 convalescent plasma (CCP) reduces hospitalizations among immunocompetent outpatients. This study evaluated recipient post-transfusion S receptor binding domain (S-RBD) IgG antibody levels and the association of progressing to hospitalization among unvaccinated outpatients with COVID-19 treated with CCP or control plasma. Method(s): This analysis focused on participants from a multicenter doubleblind, randomized, controlled trial comparing treatment of outpatients with COVID-19 convalescent plasma (CCP) or control plasma without SARS-CoV-2 antibodies. Participants with confirmed SARS-CoV-2 infection were transfused within 9-days of symptom onset between June 2020 and October 2021 (n=110 vaccinated control;n=105 vaccinated CCP;n=464 unvaccinated control;n=472 unvaccinated CCP;total n=574 control and n=577 CCP recipients). All subjects had specimens collected the day prior to transfusion (D-1), within 30 minutes after transfusion (D0), 14 (D14), 28 (D28), and 90 (D90) days post-transfusion. Ancestral SARS-CoV-2 S-RBD was measured by an in-house validated ELISA. All 54 COVID-19-related hospitalizations occurred within 2 weeks of transfusion. Result(s): Post-transfusion anti-S-RBD IgG levels on D0 were significantly greater for CCP (median=4 titer,log3) compared to control (median=2 titer,log3;p< 0.001) recipients. Neither sex nor age impacted antibody levels following CCP treatment at D14, D28, and D90. Vaccinated recipients had greater titers than unvaccinated recipients prior to transfusion with little change in titers post-transfusion. Unvaccinated recipients had low antibody titers on D-1 with CCP recipients exhibiting a significant increase in titer from D-1 to D0 compared to controls (mean fold change=1.89;p< 0.001). Among unvaccinated recipients, those who received CCP transfusion late ( >5 days after symptom onset) and had low D0 antibody levels (< 4.24 titer, log3) had the greatest proportion of hospitalizations (5.5%). In contrast, those who received CCP transfusion early (< 5 days after symptom onset) with high D0 antibody levels ( >4.24 titer, log3) had no hospitalizations. Unvaccinated CCP recipient anti-S-RBD IgG antibody levels on D0 correlated with donor anti-S-RBD IgG antibody levels (r=0.30, p< 0.001). Conclusion(s): Among unvaccinated outpatients with COVID-19, CCP recipient antibody dilutional titers after transfusion over 540 titer correlated with protection against hospitalization when transfusion occurred within 5 days of symptom onset. (Figure Presented).
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Background: The rapid development of SARS-CoV-2 mRNA vaccines has been a remarkable success of the COVID-19 pandemic, but vaccine-induced immunity is heterogeneous in immunocompromised populations. We sought to determine the immunogenicity of SARS-CoV-2 mRNA vaccines in a cohort of people with idiopathic CD4 lymphopenia (ICL). Method(s): 25-patients with ICL followed at the National Institutes of Health on a natural history protocol were evaluated between 2020-2022. Blood and serum was collected within 4-12 weeks after their second and/or third SARS-CoV-2 mRNA vaccine dose. Twenty-three matched healthy volunteers (HVs) provided blood samples at similar timepoints post-mRNA vaccination on a separate clinical protocol. Pre-vaccine blood samples were also used when available. Anti-spike and anti-receptor binding domain antibodies were measured. T-cell stimulation assays were performed to quantify SARS-CoV-2 specific T-cell responses. Comparisons were made with Wilcoxon test. Result(s): Twenty-participants with ICL had samples collected after their second mRNA vaccine and 7-individuals after the third dose. Median age at vaccination was 51-years (IQR: 44-62) and 12 were women (48%). Median CD4 T-cell count was 150 cells/muL (IQR: 85-188) at the time of vaccination, and 11-individuals (44%) had a baseline CD4 count <=100 cells/muL. HVs had a median age of 54-years (IQR: 43-60) with 13-women (56.5%). Anti-spike IgG antibody levels were significantly greater in HVs than those with ICL after 2-doses. Lower SARS-CoV-2 IgG antibody production was primarily observed in those with baseline CD4 T-cells <=100 cells/mul (Figure-1A). The decreased production in ICL remained after a third vaccine dose (Figure-1B). There was a significant correlation between anti-spike IgG and baseline CD4 count. Spike-specific CD4 T-cell responses in volunteers compared to those with ICL demonstrated similar levels of activation induced markers (CD154+CD69+) and cytokine production (IFNgamma+, TNFalpha+, IL2+) after two or three mRNA vaccine doses. Quantitatively the smallest responses were observed in those with lower baseline CD4 T-cells (Figure 1C-D). Minimal SARS-CoV-2 CD8 T-cell responses were detected in both groups. Conclusion(s): Patients with ICL and baseline CD4 T-cells >100 mount similar humoral and cellular immune responses to SARS-CoV-2 vaccination as healthy volunteers. Those with baseline CD4 T-cells <=100 have impaired vaccine- induced immunity and should be prioritized to additional boosters and continue other risk mitigation strategies. (Figure Presented).
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Background: SARS-CoV-2 is a highly contagious respiratory virus responsible for COVID-19 pandemic. To understand the role of antibodies in neutralization, our study quantified circulating levels of IgA/IgG and IgG subtypes induced at different days post onset of symptoms, in severe and non severe patients. Objective(s): To quantify circulating levels of IgA, IgG and IgG subclass in severe and non severe patients induced at different days post onset of symptoms. Material(s) and Method(s): Serum or plasma samples collected from 79 COVID-19 patients were used. Indirect SARS-CoV-2 specific IgA, IgG, and IgG subclass specific ELISAs were performed. Antibody titers between severe and non severe patients were compared at different times post onset of clinical symptoms. Titers in ELISA were correlated to neutralizing antibody titers. Results and Conclusion(s): Over 75% patients were positive for IgA and IgG antibodies in the first week. The ELISA titers did not differ during the first week of infection. However, patients with severe disease exhibited raised titers. Neutralizing antibody titers correlated with the ELISA titers in mild presentation but not in severe disease. IgA and IgG1 antibodies correlated stronger with neutralizing antibodies. The findings highlighted that IgA together with IgG play an important in SARS-CoV-2 neutralization.
ABSTRACT
Backgrounds: Although conventional therapies have played an essential role in the treatment of many diseases, emerging diseases require new treatment methods with less complications. Therefore, it is important to develop an effective vaccine for infections caused by the coronavirus to prevent mortality and create immunity the community. Material(s) and Method(s): In this research bioinformatics tools were used to design a vaccine against the M membrane protein of SARS-CoV-2. A total of 27 epitopes confined to B cells and MHC I and II alleles were structurally constructed in M protein for immune stimulation and antibody recognition which were used in the construction of a chimeric peptide vaccine. Finding(s): The vaccine was predicted to be a stable, antigenic, and non-allergenic compound. TRL5/vaccine complex analysis and docking simulation indicated a sufficiently stable binding with appropriated receptor activation. The immune response simulation following hypothetical immunization indicated the potential of this vaccine to stimulate the production of active and memory B cells, CD8 + T and, CD4 + T cells, and effective immunological responses induced by Th2 and Th1. Conclusion(s): The analysis of in-silico processes showed that the vaccine structure induced high antigenicity and good cellular immunity in the host body and stimulates various immune receptors such as TLR5, MHC I, and MHC II. Vaccine function was also associated with an increase in IgM and IgG antibodies and a set of Th1 and Th2 cytokines. But the final confirmation of the effectiveness of the designed vaccine requires clinical processes.Copyright © 2022, TMU Press.
ABSTRACT
Background: SARS-CoV-2 seroprevalence data in women living with HIV (WLHIV), their infants and associated risk factors in this subpopulation remain limited. We retrospectively measured SARS-CoV-2 seroprevalence from 09/2019- 12/2021 among WLHIV and their children in the PROMOTE observational cohort in Uganda, Malawi, and Zimbabwe prior to widespread SARS-CoV-2 vaccination in those countries. Method(s): Sociodemographic, clinical data and blood were collected q6 months. Plasma stored during 3 waves of the COVID-19 pandemic in East/ Southern Africa were tested for SARS-CoV-2 specific IgG antibodies (Ab) using serological assays that detect adaptive immune responses to SARS-CoV-2 spike protein. Modified-Poisson regression models were used to calculate prevalence rate ratios (PRR) and 95% confidence intervals (CI) to identify sociodemographic and clinical risk factors. Result(s): Plasma samples from 979 PROMOTE mothers and 1332 children were analysed. We found no significant differences in baseline characteristics between participants testing positive (+) and negative (-) for SARS-CoV-2 Ab. Overall maternal SARS-CoV-2 seroprevalence was 57.6% (95%CI: 54.5-60.7) and 39.3% (95%CI: 36.7-41.9) for infants. The earliest + result was detected from a sample collected on 09/2019, in Malawi. Factors significantly associated with SARS-CoV-2 seropositivity were country of origin (reference Uganda, aPRR 1.45, 95%CI: 1.24-1.69) and non-breastfeeding mother (aPRR=1.22, 95%CI: 1.02-1.48). Children above 5 years had a 10% increased risk of SARS-CoV-2 seropositivity (aPRR=1.10, 95%CI: 0.90-1.34) when compared to younger children. We found no statistically significant association with sanitation, household density, distance to clinic, maternal employment, ART regimen or viral load. Mother/infant SARS-CoV-2 serostatuses were discordant in 373/865 (43.1%) families tested: mothers+/children- in 51.2%;mothers-/children+ in 12%;child+/sibling+ concordance was 21.4%. Conclusion(s): These SARS-CoV-2 seroprevalence data indicate that by late 2021, about half of mothers and about a third of children in a cohort of HIV-affected families in eastern/southern Africa had been infected with SARS-CoV-2. Breastfeeding was protective for mothers, likely because of the need to stay home for young children. Discordant results between children within same families underscores the need to further understand transmission dynamics within households.
ABSTRACT
The aim is to examine dynamics of avidity maturation of IgG antibodies against SARS-CoV-2 RBD depending on the type of immunization (vaccination or infection), as well as on the duration and frequency of immunization. Materials and methods. The study was performed on two sample cohorts collected at two time points during COVID-19 pandemic. The first cohort (group No. 1) consisted of 87 samples of blood sera obtained from COVID-19 convalescents in the period from March to September 2020. The second cohort included 204 samples obtained in September 2021 from two patient groups. Group No. 2 (n = 64) - patients immunized with a full course of Gam-Covid-Vac, group No. 3 (n = 140) - COVID-19 convalescent patients and subjects vaccinated with Gam-Covid-Vac ("hybrid immunity"). Results and conclusion. The dynamics of avidity maturation for SARS-CoV-2 RBD IgG antibodies depending on the method and frequency of immunization, showed that the most effective immunity was formed in COVID-19 convalescent patients and subjects vaccinated with a full course of Gam-Covid-Vac. The "hybrid" immunity showed not only a significantly higher (compared with groups No. 1 and No. 2) level of IgG antibodies (median 228 BAU/ml vs 75 or 119 BAU/ml, p < 0.001), but also a higher level of avidity (IA 90.5% vs 54.5 and 76.6, respectively, p < 0.001, 4M urea). In the test for assessing the avidity index with the denaturing agent 8M urea in patients with "hybrid immunity", the median level of IA was 25% versus 14.8% and 16% in COVID-19 convalescents and vaccinated subjects (p < 0.001), only in 8 patients IA was higher than 50%. While comparing a single infection of COVID-19 with a full course of Gam-Covid-Vac, it was shown that vaccination leads to higher IgG levels (median values in groups 119 and 75 BAU/ml, p < 0.001) and to a higher avidity index (median 76.6% vs 54.5%). Thus, the more rapid induction of high-avidity antibodies was in vaccinated individuals at early stages of immunization (up to 4 months), during the period when IgG avidity maturation has not yet been completed. Our results showed that during this period vaccination leads to production of antibodies with avidity index at median level of 82% versus 36% in COVID-19 convalescents at similar time point.Copyright © 2023 Saint Petersburg Pasteur Institute. All rights reserved.