Evaluation of Antibody Response and Side Effects Related to the Number of Inactive and mRNA Vaccine Doses Against COVID-19 in Healthcare Workers

Introduction: Studies are showing that a high antibody response increases the protection against variants in the fight against the COVID-19 pandemic. In this study, we aimed to investigate the relationship between antibody response and side effects based on the number of doses administered to healthcare workers who were vaccinated against COVID-19. Material(s) and Method(s): Healthcare workers, who were vaccinated with two doses of BNT162b2 (Group 1), a single dose of BNT162b2 following two doses of CoronaVac (Group 2), or two doses of BNT162b2 following two doses of CoronaVac (Group 3), were randomly assigned to this study. Serum samples were taken from the participants 30 +/- 2 days after the last vaccination date, and the SARSCoV- 2 anti-spike S1 RBD IgG test was administered to these samples. A questionnaire was conducted detailing the demographics of the patients as well as their post-vaccination complaints. The results were analyzed statistically. Analysis results with a p-value of <0.05 were considered significant. Result(s): A total of 179 healthcare professionals with a mean age of 41.7 +/- 10.6 years were included in our study. Of the studied samples, 95.5% (n= 171) were interpreted as anti-spike S1 RBD IgG seropositive. Positivity rates and mean antibody levels were 93.2%, 95.9%, 97.8%, and 107.4 +/- 117.1, 152.7 +/- 108.5, 201.4 +/- 114.9 (AU/mL) for Group 1, Group 2, and Group 3, respectively (p< 0.05). In general, no significant differences in antibody response were seen based on gender or age. However, a significant correlation was found between the occurrence of vaccine-related side effects and antibody titer (p< 0.001). The most common side effect was pain in the area where the vaccine was administered, with a rate of 77.4% (n= 48). More vaccine-related side effects were reported in participants under the age of 40 and in female healthcare workers. Conclusion(s): We believe that booster doses are effective for increasing the immune response and thus protecting against COVID-19. More extensive research should be conducted to confirm the link between the occurrence of vaccine-related side effects and antibody titer. Furthermore, studies on the safety of increasing the number of vaccine doses are required.Copyright © 2023 Bilimsel Tip Yayinevi. All rights reserved.

High seroprevalence against SARS-CoV-2 in non-vaccinated patients with inflammatory bowel disease from Northern India.

BACKGROUND: The information on seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among patients with inflammatory bowel disease (IBD) and its comparison to healthy controls is sparse. We compared the seroprevalence rates in patients with IBD and healthy controls (HCs). METHODS: Patients with IBD and HCs (contact of patients) underwent SARS-CoV-2 antibody testing (chemiluminescent immunoassay: Siemens kit IgG against antigen-S1RBD) between July 2020 and April 2021. Information on demography, disease characteristics, drug history and past history of SARS-CoV-2 infection were noted. Patients on 5-aminosalicylic acid or no treatment were considered not on immunosuppressants and those who had received steroids, thiopurines or methotrexate within six months of inclusion were considered being on immunosuppressants. RESULTS: A total of 235 patients (51.9%, males; mean age, 38.7 ± 12.4 years; median disease duration, 60 months [interquartile range, IQR: 36-120]) (ulcerative colitis [UC]: 69.4%, Crohn's disease [CD]: 28.9%, IBD unclassified [IBDU]: 1.7%) and 73 HCs (mean age, 39.6 ± 10.9 years, 80% males) were enrolled. Of the 235 patients, 128 (54.5%) patients were on immunosuppressants and 107 (45.5%) were not on immunosuppressants. Seventy-four (31.5%) patients were seropositive, of which two (0.9%) had previous history of SARS-CoV-2 infection and none received coronavirus disease-19 (COVID-19) vaccine. Seroprevalence between IBD patients and HCs (32% vs. 27%, p > 0.05) and between patients with and without immunosuppressants (28.1% vs. 36%, p > 0.05) was similar. Age, gender, disease type, duration and activity in the last six months; and medication use were similar between patients with positive and negative serology. There was a progressive increase in seroprevalence from July 2020 to April 2021. CONCLUSION: Up to 1/3rd of patients with IBD were seropositive for immunoglobulin G (IgG) SARS-Cov-2 antibody indicating high seroprevalence in patients with IBD from Northern India.

The evolution of the spike protein and hACE2 interface of SARS-CoV-2 omicron variants determined by hydrogen bond formation.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first detected in December 2019. As of mid-2021, the delta variant was the primary type; however, in January 2022, the omicron (BA.1) variant rapidly spread and became the dominant type in the United States. In June 2022, its subvariants surpassed previous variants in different temporal and spatial situations. To investigate the high transmissibility of omicron variants, we assessed the complex of spike protein 1 receptor-binding domain (S1RBD) and human angiotensin-converting enzyme 2 (hACE2) from the Protein Data Bank (6m0j, 7a91, 7mjn, 7v80, 7v84, 7v8b, 7wbl and 7xo9) and directly mutated specific amino acids to simulate several variants, including variants of concern (alpha, beta, gamma, delta), variants of interest (delta plus, epsilon, lambda, mu, mu without R346K) and omicron variants (BA.1, BA.2, BA.2.12.1, BA.4, BA.5). Molecular dynamics (MD) simulations for 100 ns under physiological conditions were then performed. We found that the omicron S1RBD-hACE2 complexes become more compact with increases in hydrogen-bond interactions at the interface, which is related to the transmissibility of SARS-CoV-2. Moreover, the relaxation time of hydrogen bonds is relatively short among the omicron variants, which implies that the interface conformation alterations are fast. From the molecular perspective, PHE486 and TYR501 in omicron S1RBDs need to involve hydrogen bonds and hydrophobic interactions on the interface. Our study provides structural features of the dominant variants that explain the evolution trend and their increased contagiousness and could thus also shed light on future variant changes.

Increased Levels of Autoantibodies against ROS-Modified Proteins in Depressed Individuals with Decrease in Antibodies against SARS-CoV-2 Antigen (S1-RBD).

Coronavirus 2019 (COVID-19) disease management is highly dependent on the immune status of the infected individual. An increase in the incidence of depression has been observed during the ongoing COVID-19 pandemic. Autoantibodies against in vitro reactive oxygen species (ROS) modified BSA and Lys as well as antibodies against receptor binding domain subunit S1 (S1-RBD) (S1-RBD-Abs) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were estimated using direct binding and competition ELISA. Serum samples were also tested for fasting blood glucose (FBG), malondialdehyde (MDA), carbonyl content (CC), interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α). Significant structural changes were observed in ROS modified BSA and Lys. Female depressed subjects who were also smokers (F-D-S) showed the highest levels of oxidative stress (MDA and CC levels). Similarly, increased levels of autoantibodies against ROS modified proteins were detected in F-D-S subjects, in males who were depressed and in smokers (M-D-S) compared to the other subjects from the rest of the groups. However, contrary to this observation, levels of S1-RBD-Abs were found to be lowest in the F-D-S and M-D-S groups. During the pandemic, large numbers of individuals have experienced depression, which may induce excessive oxidative stress, causing modifications in circulatory proteins. Thus, the formation of neo-antigens is induced, which lead to the generation of autoantibodies. The concomitant effect of increased autoantibodies with elevated levels of IFN-γ and TNF-α possibly tilt the immune balance toward autoantibody generation rather than the formation of S1-RBD-Abs. Thus, it is important to identify individuals who are at risk of depression to determine immune status and facilitate the better management of COVID-19.

Detection of SARS-CoV-2 Neutralizing Antibodies in Vaccinated Pregnant Women and Neonates by Using a Lateral Flow Immunoassay Coupled with a Spectrum-Based Reader.

The focus of this study was to investigate the detection of neutralizing antibodies (Nabs) in maternal serum and cord blood as the targeted samples by employing a lateral flow immunoassay combined with a spectrum reader (LFI-SR) and the correlation of Nab protection against different types of SARS-CoV-2. We enrolled 20 pregnant women who were vaccinated with the Moderna (mRNA-1273) vaccine during pregnancy and collected 40 samples during delivery. We used an LFI-SR for the level of spike protein receptor binding domain antibody (SRBD IgG) as Nabs and examined the correlation of the SRBD IgG concentration and Nab inhibition rates (NabIR) via enzyme-linked immunosorbent assays (ELISA). The LFI-SR had high confidence for the SRBD IgG level (p < 0.0001). Better NabIR were found in wild-type SARS-CoV-2 (WT) compared to Delta-type (DT) and Omicron-type (OT). Women with two-dose vaccinations demonstrated greater NabIR than those with a single dose. The cut-off value of the SRBD IgG level by the LFI-SR for NabIR to DT (≥30%; ≥70%) was 60.15 and 150.21 ng/mL for mothers (both p = 0.005), and 156.31 (p = 0.011) and 230.20 ng/mL (p = 0.006) for babies, respectively. An additional vaccine booster may be considered for those mothers with SRBD IgG levels < 60.15 ng/mL, and close protection should be given for those neonates with SRBD IgG levels < 150.21 ng/mL, since there is no available vaccine for them.

of the 2nd dose of Pfizer-BioNTech vaccine administration which was given to the medical college students at Diyala University

Background: Fighting the Covid-19 pandemic is one of the global priorities now, and the most important type of pandemic control is vaccination. Pfizer-Biotech is considered one of the most important vaccines currently because of its high effectiveness in stimulating the immune system, despite limited data regarding the duration of the response and its side effects. The goal of this study is to assess the response ofSARS CoV-2 S1-RBD IgG andInterleukin-15 after 30 and 120days fromthe 2nd dose ofPfizer-BioNTech vaccine which applied on themedical college students at Diyala university. Methodology: This study began after the obtainment of the Medical College of the University of Diyala, the Medical College of Al-IraqiaUniversity, and the Iraqi Ministry of Health approvals . It continued from October 2021 until March 2022.A total of45 male and femaleparticipants from the College of Medicine( DiyalaUniversity)students who took thetwo doses of Pfizer-BioNTech and were divided into two groups: 1 month (30 days) and 4 months (120 days) after the full vaccination (two doses).A 5 ml of their blood was taken two times (30 days and 120 days after the 2nd dose of thePfizer-BioNTech vaccine) in the postgraduate laboratories inside the Diyala Medical College. A serological analysis to quantify IL-15 and SARS CoV-2 S1-RBD IgG has been done using BT LAB/ Bioassay Technology Laboratory/ Human Interleukin 15 ELISA Kit from CHINA andDiasino/ SARS CoV-2 S1-RBD IgG ELISA Kit/ CHINA respectively. All the lab work happened in the postgraduate laboratories inside the Diyala Medical College. Demographic information (Age and Gender) has been collected from the participants. These participants were split into two groups depending on the time after the 2nd of Pfizer-BioNTech vaccine dose (1 month and 4 months, respectively). STATISTICA (version 12 )and SPSS (version 26 ) were used to input, review and data analysis. Essential approaches of percentages and frequencies were used for qualitative variables, while, average and standard deviation were used for quantitative variables. For both IL-15 and SARS CoV-2 S1-RBD IgG, less than 0.05 of a P-value was considered considerable. Result(s): The ratio, according to gender, was (17.8: 82.2) while the age Average was (20.9 years old). The serum data of IL-15 and SARS-CoV-2 S1-RBD IgG levels after 1 month (30 days) and 4 months (120 days) were statistically non-parametric. Mann-Whitney test (Independent two samples), showeda considerabledrop(P<0.05) of IL-15as well as SARS CoV-2 S1-RBD IgGserum levels in the 4th-monthsgroup compared to the 1-monthgroup. Conclusion(s): Interleukin-15 and SARS CoV-2 S1-RBD IgG serum levels significantly droped after 120days of the 2nd dose of Pfizer-BioNTech vaccine. Copyright © 2022, Anka Publishers. All rights reserved.

Seroprevalence of Anti-S1-RBD Antibodies in Pre-pandemic and Pandemic Subjects From Hail Region, KSA.

Background: Two years into the pandemic, yet the threat of new SARS-CoV-2 variants continues to loom large. Sustained efforts are required to fully understand the infection in asymptomatic individuals and those with complications. Identification, containment, care, and preventative strategies rely on understanding the varied humoral immune responses. Methods: An in-house ELISA was developed and standardized to screen for serum IgG antibodies against the SARS-CoV-2 S1-RBD protein as an antigen. This study aims to investigate the seroprevalence of serum antibodies against S1-RBD antigen in pre-pandemic (n = 120) and during the early pandemic period (n = 120) in subjects from the Hail region, KSA and to correlate it with clinical and demographic factors. Results: Samples collected from both male (n = 60) and female (n = 60) subjects during the pandemic in the age groups of 20-40 (0.31 ± 0.029 and 0.29 ± 0.024, respectively) and 41-60 years (0.35 ± 0.026 and 0.30 ± 0.025, respectively) showed significantly higher levels of serum antibodies against S-RBD antigen than the age-matched pre-pandemic samples [male (n = 60) and female (n = 60)]. Pandemic subjects exhibited significantly (p < 0.01) higher inhibition (80-88%) than age-matched pre-pandemic subjects (32-39%). Antibodies against S1-RBD antigen were detected in approximately 10% of the total pre-pandemic population (males and females). However, subjects > 60 years did not show antibodies. Conclusion: Antibody levels increased in samples collected during the pandemic, even though these subjects were not clinically COVID-19 positive. A small number of pre-pandemic subjects showed serum antibodies, suggesting prior exposure to other coronaviruses in the region. With dwindling neutralizing antibody levels and reduced vaccine efficacy against newer variants, it remains crucial to develop better assays for surveillance, management, and future research.

Analysis of Factors Affecting Neutralizing Antibody Production after COVID-19 Vaccination Using Newly Developed Rapid Point-of-Care Test.

(1) Objective: To investigate the factors that affect rates of neutralizing antibody production and duration after vaccination using the newly developed SARS-CoV-2 POCT. (2) Methods: The production of immunoglobulin and neutralizing antibody in clinical subjects who completed various vaccines was analyzed using the POCT, the semi-quantitative was interpreted by measurement application, and the quantified neutralizing antibody titers were using the ELISA. (3) Results: According to the clinical performance analysis of the POCT, the clinical sensitivity and the specificity were 96.8% (90/93) and 97.7% (167/171), respectively, for the S1 RBD IgG antibody. The clinical sensitivity was 92.22% (83/90), and the clinical specificity was 100.00% (174/174) for neutralizing antibodies. Factors influencing antibody production were analyzed using the whole blood of the five types of second-completed vaccinators (N = 736, 20-80 years old). General and neutralizing antibody and showed significant differences in age (p < 0.0001), vaccine type (p < 0.0001), inoculation interval (p < 0.0001), pain score (p < 0.0001), diabetes (p < 0.0001), and hypertension (p = 0.002). The gender (p = 0.021) and chronic fatigue (p = 0.02) did not show the significance. (4) Conclusions: An acquisition of immunoglobulin and neutralizing antibody varies according to vaccine type, age, days after vaccination, pain degree after vaccination, and underlying diseases. The POCT used in this study will be utilized for clinical recommendations such as deciding whether to receive additional vaccines through the immediate rapid determination of neutralizing antibody generation in the clinical site.

Immunogenicity and safety of the BNT162b2 COVID-19 mRNA vaccine in PLWH: A monocentric study in Bari, Italy.

In March, people living with HIV infection (PLWH) were included in the risk category of fragile people for severe COVID-19 receiving priority access to vaccination with BNT162b2 vaccine. The aim of the study was to evaluate the immunogenicity and safety of the two doses regimen. The antibodies titer for severe acute respiratory syndrome-related coronavirus-2 (SARS-CoV-2) was evaluated after 21 days since the first administration (Time 1), 1 (Time 2), and 3 (Time 3) months post-vaccination. Information regarding virological and immunological conditions at baseline, previous SARS-CoV-2 state of infection, other immunodeficiencies, current antiretroviral therapy (ART), comorbidities, and severe adverse events (SAE) to vaccination was collected. Six hundred and ninety-seven patients were tested for quantitative anti-spike antibodies at Time 1, 577 patients had a second detection at Time 2, and 491 patients had the third detection. Baseline characteristics of the study population are reported in Table 1. At the time of vaccine administration, all patients were on ART (except one long-term nonprogressor); 632 (90.7%) patients had undetectable HIV-RNA; 12 (1.7%) patients were immunosuppressed due to chemotherapy or other immunosuppressive drugs; 345 (49.5%) patients had at least one COVID-19 related comorbidity and 155 (22.2%) had two or more comorbidities. No SAEs were reported. Final serological results are available for 694 patients after the first dose, 577 and 491 after the second and third ones, respectively; positive titer (values ≥ 50 AU/ml) was demonstrated in 653 (94.1%), 576 (99.8%), 484 (98.6%) patients, respectively. Only one patient was a nonresponder after completing vaccination, who was a newly diagnosed one for HIV infection. All vaccinations were well tolerated, with no SAEs. BNT162b2 mRNA vaccine was immunogenic and safe in PLWH.

Long-Term Humoral Immune Response against SARS-CoV-2 after Natural Infection and Subsequent Vaccination According to WHO International Binding Antibody Units (BAU/mL).

The new WHO reference standard allows for the definition of serum antibodies against various SARS-CoV-2 antigens in terms of binding antibody units (BAU/mL) and thus to compare the results of different ELISA systems. In this study, the concentration of antibodies (ABs) against both the S- and the N-protein of SARS-CoV-2 as well as serum neutralization activity were evaluated in three patients after a mild course of COVID-19. Serum samples were collected frequently during a period of over one year. Furthermore, in two individuals, the effects of an additional vaccination with a mRNA vaccine containing the S1-RBD sequence on these antibodies were examined. After natural infection, the antibodies (IgA, IgG) against the S1-protein remained elevated above the established cut-off to positivity (S-IgA 60 BAU/mL and S-IgG 50 BAU/mL, respectively) for over a year in all patients, while this was not the case for ABs against the N-protein (cut-off N-IgG 40 BAU/mL, N-IgA 256 BAU/mL). Sera from all patients retained the ability to neutralize SARS-CoV-2 for more than a year. Vaccination resulted in a rapid boost of antibodies to S1-protein but, as expected, not to the N-protein. Most likely, the wide use of the WHO reference preparation will be very useful in determining the individual immune status of patients after an infection with SARS-CoV-2 or after vaccination.

Quantitative Detection of Anti-SARS-CoV-2 Antibodies Using Indirect ELISA.

OBJECTIVE: Real-time reverse transcription-polymerase chain reaction is the gold standard for the diagnosis of COVID-19, but it is necessary to utilize other tests to determine the burden of the disease and the spread of the outbreak such as IgG-, IgM-, and IgA-based antibody detection using enzyme-linked immunosorbent assay (ELISA). MATERIALS AND METHODS: We developed an indirect ELISA assay to quantitatively measure the amount of COVID-19 IgG, IgM, and IgA antibodies present in patient serum, dried blood, and plasma. RESULTS: The population cutoff values for positivity were determined by receiver operating characteristic curves to be 1.23 U/mL, 23.09 U/mL, and 6.36 U/mL for IgG, IgM, and IgA, respectively. After albumin subtraction, the specificity remained >98% and the sensitivity was 95.72%, 83.47%, and 82.60%, respectively, for IgG, IgM, and IgA antibodies to the combined spike subunit 1 receptor binding domain and N proteins in serum. Plasma and dried blood spot specimens were also validated on this assay. CONCLUSION: This assay may be used for determining the seroprevalence of SARS-CoV-2 in a population exposed to the virus or in vaccinated individuals.

EDTA-Induced Pseudothrombocytopenia up to 9 Months after Initial COVID-19 Infection Associated with Persistent Anti-SARS-CoV-2 IgM/IgG Seropositivity.

Platelets have a role in vascular complications of COVID-19-related viral coagulopathy. Although immune-induced thrombocytopenia has been described mostly in moderate-to-severe COVID-19, the prognostic role of platelet count in COVID-19 is still controversial. Pseudothrombocytopenia has been reported to represent COVID-19-associated coagulopathy in critical illness, and transient EDTA-dependent pseudothrombocytopenia lasting less than 3 weeks was described in a patient with severe acute COVID-19 pneumonia. In our case study, EDTA-induced pseudothrombocytopenia was still present at 9 months after an initial SARS-CoV-2 virus infection in an apparently recovered 60 year old man. The persistence of antinucleocapside and antispike antibodies 9 months after the initial infection suggests that EDTA-induced pseudothrombocytopenia may be related to anti-SARS-CoV-2 IgG or IgM antibodies. We should acknowledge the possibility that pseudothrombocytopenia may also appear in some patients after seroconversion after the launch of large-scale vaccination programs.

Anti-spike S1 receptor-binding domain antibodies against SARS-CoV-2 persist several months after infection regardless of disease severity.

Data regarding the immunological memory and long-time kinetics of immunoglobulin (IgG) against viral nucleoprotein (NP) and spike protein S1 receptor-binding domain (S1RBD) of Severe Acute Respiratory Syndrome-associated Coronavirus 2 (SARS-CoV-2) are lacking. All consecutive COVID-19 patients admitted to our Clinic between March 1, 2020, and May 1, 2020, who were tested at hospital admission for anti-S1RBD and anti-NP IgG were enrolled. Serum samples were tested for anti-SARS-CoV-2 antibodies with the use of two commercially available enzyme-linked immunosorbent assays. Results are expressed as optical density measurements at 450 nm (OD450 ). Overall, 111 patients were included; the median (q1-q3) age was 57 (49-73) years, 59 (53%) males. According to disease severity, 31 (28%), 47 (42%), and 33 (30%) patients were considered affected by mild/moderate, severe, and critical SARS-CoV-2 infection, respectively. During hospitalization, patients with the critical disease showed a higher peak value of both anti-NP (median OD450 : 3.66 vs. 3.06 vs. 3.00 respectively, p = .043) and anti-S1RBD IgG (median OD450 : 2.33 vs. 1.6 vs. 0.91, respectively, p < .001). By testing 48 subjects 6 months or above from discharge, a significant decrease of anti-NP IgG was observed (r: -0.5838; p < .0001), whereas anti-S1RBD IgG showed only a modest reduction (r: -0.1507; p = .0647). Accordingly, 10 (21%) and 2 (4%) patients had a negative serological status for anti-NP and anti-S1RBD IgG, respectively; no association with clinical severity was found. IgGs against SARS-CoV-2 persisted several months after discharge, regardless of disease severity, suggesting that vaccination could be a valid strategy to fight the pandemic.