Comparative study of SARS-CoV-2 antibody titers between male and female COVID-19 patients living in Kurdistan region of Iraq

Impact of Vaccination Time on Anti-SARS-CoV-2 Antibody Levels in Adults: A Quasi-experimental Study

BACKGROUND AND AIM

Vaccination time may provide an opportunity to advance immunogenicity in terms of the immune system's circadian nature. This analytical study was planned to determine the impact of forenoon and afternoon administration of the COVID-19 vaccine to adults on the magnitude of antibody response.

METHOD

A total of 33 healthy adults with no history of COVID-19 infection or any other disease participated in the study. They were allotted a forenoon (900-1200 hours) or afternoon (1200-500 hours) slot for vaccination. They were categorized as a forenoon or afternoon group, with 16 subjects in the forenoon and 17 in the afternoon group. With the consent of the participants, a blood sample was collected before vaccination, 30 days after the first and 30 days after the second dose of vaccination from all the subjects. The antibody titer response was measured using a commercial semi-quantitative assay, SARS-CoV-2 IgG II.

RESULTS

The baseline antibody titer against COVID-19 was 51.41 ± 22.22 AU/mL and 53.21 ± 15.67 AU/mL in the forenoon and afternoon groups, respectively, which increased to 15773.00 ± 3231.41 AU/mL and 12970.82 ± 7608.00 AU/mL after 30 days of the first dose of the COVID-19 vaccine in the forenoon and afternoon groups, respectively. This further increased to 37007.00 ± 1697.75 AU/mL and 38012.00 ± 14001.16 AU/mL after 30 days of the second dose of the COVID-19 vaccine in the forenoon and afternoon groups, respectively. There was no difference in antibody response in subjects with forenoon and afternoon vaccinations. There was no significant difference in antibody titer in males vs. females. The study reported that antibody titers decreased with increasing age and BMI of participants.

CONCLUSION

The time of the day of vaccination does not impact the immune response to COVID-19, but age and BMI are important factors to consider during vaccination against SARS-CoV-2 in the adult population.

Sensitivities of a Rapid Test Versus an ELISA Kit for Detecting Anti-SARS-CoV-2 IgM/IgG in Sera from an Egyptian Cohort

This study aimed to compare diagnostic sensitivities of a rapid test (Rt) and an ELISA kit for detecting anti-SARS-CoV-2 IgM/IgG in virus-RT-PCR-positive (VPP) and virus-RT-PCR-unchecked (VPU) subjects in an Egyptian cohort during the first wave of SARS-CoV-2 infection. The results revealed higher sensitivity of the Rt for detecting IgM/IgG in the VPP subjects. Both the Rt and ELISA showed identical sensitivities for IgM detection in the VPU subjects. The ELISA was more sensitive for detecting IgG in the VPU subjects. Generally, within both the VPP and the VPU groups, Rt was more sensitive for detecting IgM/IgG among the symptomatic (S) compared to asymptomatic (AS) subjects than ELISA. Within the VPP group, the Rt was more sensitive for detecting both IgM/IgG among the AS subjects than ELISA. In the VPU group, the Rt was more sensitive for detecting IgM among the S subjects than ELISA. The ELISA was more sensitive for detecting IgM/IgG among AS subjects than the Rt. From these results we concluded that, despite the limitation of sample size, this study indicates suitability of the used Rt for detecting anti-SARS-CoV-2 IgM/IgG among S subjects and sheds light on possibility of relying on the used ELISA for IgG detection among AS human subjects.

Study of some immunological signatures and their association with COVID-19 in a sample of recovered Iraqi patients

Since its emergence about two years ago, the novel coronavirus has continued to be a challenge and threat to public health, struck most parts of the world, leaving more than half a billion cases of infection and more than five million deaths. Immune response abnormalities post-infection with SARS-CoV-2 have been reported, and the mechanisms that lead to them are still ambiguous. This study was conducted to evaluate some immunological markers in the serum samples of COVID-19 convalescent patients and investigate the association of these immunological signatures with their age and sex. The serum levels of immunoglobulin G, interleukin-1 beta, and interferon lambda-1 of 75 patients and 50 healthy control group members were measured, with 55 % males and 45 % females participating and ages ranging from 20 to 80 years. The measurement of the immunological signatures was performed using the enzyme-linked immunosorbent assay (ELISA). The result revealed highly significant elevated levels of the serum immunological signatures of the convalescent group in comparison to the control group, with P-values of 0.00001 for each signature. Moreover, age was observed to have an association with an elevated level of the immunological signatures as it increased in the elderly, whereas no association with sex was detected. The findings strongly suggest that COVID-19 infection results in a persistent inflammatory response, which leads to prolonged post-recovery symptoms. Post-COVID-19 syndrome necessitates additional research to clarify its pathophysiology, pathogenesis, and long-term implications.

Assessment of the longitudinal humoral response in non-hospitalized SARS-CoV-2-positive individuals at decentralized sites: Outcomes and concordance

Introduction

Early in the COVID-19 pandemic, reagent availability was not uniform, and infrastructure had to be urgently adapted to undertake COVID-19 surveillance.

Methods

Before the validation of centralized testing, two enzyme-linked immunosorbent assays (ELISA) were established independently at two decentralized sites using different reagents and instrumentation. We compared the results of these assays to assess the longitudinal humoral response of SARS-CoV-2-positive (i.e., PCR-confirmed), non-hospitalized individuals with mild to moderate symptoms, who had contracted SARSCoV-2 prior to the appearance of variants of concern in Québec, Canada.

Results

The two assays exhibited a high degree of concordance to identify seropositive individuals, thus validating the robustness of the methods. The results also confirmed that serum immunoglobulins persist ≥ 6 months post-infection among non-hospitalized adults and that the antibodies elicited by infection cross-reacted with the antigens from P.1 (Gamma) and B.1.617.2 (Delta) variants of concern.

Discussion

Together, these results demonstrate that immune surveillance assays can be rapidly and reliably established when centralized testing is not available or not yet validated, allowing for robust immune surveillance.

The Levels of Anti-SARS-CoV-2 Spike Protein IgG Antibodies Before and After the Third Dose of Vaccination Against COVID-19

Purpose

The COVID-19 pandemic has been going on for almost three years, and so far, many preventive and therapeutic strategies have been developed. The issue of subsequent booster vaccinations is currently being discussed. We aimed to analyze how the third dose of vaccination against COVID-19 correlates with the dynamics of IgG anti-SARS-CoV-2 spike protein antibody levels in a group of healthy people.

Patients and Methods

The prospective study included 93 participants before and after a second booster of COVID-19 vaccination, from whom 4 blood samples were collected at intervals. The levels of IgG anti-SARS-CoV-2 in serum were identified using the chemiluminescent immunoassay specific for the receptor-binding domain (RBD) of the S1 protein. The analysis of the results was performed using appropriate statistical methods, considering p <0.05 as a statistically significant value.

Results

The IgG levels were significantly higher and less diverse after the same follow-up time from the second booster vaccination compared to the first booster. The antibody levels were positively correlated with female, healthcare workers, the elderly and participants with a negative COVID-19 history. Furthermore, the increase in IgG antibodies after the second booster vaccination correlated inversely with the baseline level of antibodies before the vaccination. The latest results showed that antibody levels dropped 1.5-fold after approx. 10 months from the second booster vaccination but still remained at a protective level.

Conclusion

Booster vaccinations seem to better stimulate immune memory, and in the case of borderline IgG level induces the greatest increase in antibodies. It is worth considering the individual parameters of patients and measuring antibodies before vaccination.

Establishing the First COVID-19 Convalescent Plasma Biobank in Jordan

Background: Antibodies with the specialized ability to fight infection can be found in the blood of individuals who have recovered from or have been vaccinated against COVID-19. As a result, plasma from these individuals could be used to treat critically ill patients. This treatment is known as convalescent plasma (CCP) therapy. Methods: Plasma units from 1555 consented healthy blood bank donors were collected from February to September 2021. Blood units were tested for the quantitative determination of Immunoglobulin G (IgG) antibodies to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus using one of the following assays based on the availability of the kits: The LIAISON^® SARS-CoV-2 TrimericS IgG assay or the Abbott SARS-CoV-2 IgG II Quant assay. Results: Among the tested donors, 1027 participants tested positive for neutralizing anti-SARS-CoV-2 IgG antibodies (66.04%). There were 484 donors whose plasma qualified to be used for CCP therapy (47.13%) and 214 CCP units were stored in the COVID-19 convalescent biobank. Conclusion: We were able to identify and store 214 fresh frozen plasma units qualified for CCP-plasma therapy for COVID-19 patients according to World Health Organization standards. Hence, we established the first COVID-19-convalescent plasma data and plasma biobank for treating COVID-19-infected cancer patients in Jordan and the region.