Immune response to COVID-19 vaccination in a population with and without a previous SARS-CoV-2 infection

Anti-RBD IgG dynamics following infection or vaccination

Identifying parameters influencing SARS-CoV-2 antibody dynamics post infection or vaccination is crucial for refining vaccination strategies. In a longitudinal analysis of 1340 samples from 375 healthcare workers, we characterized peak serological response and IgG half-life. Peak antibody titers post 2 vaccine doses were ∼ 20 times higher than natural infection; conversely, infected individuals had extended antibody half-life. Clinical and demographical factors such as BMI, age and smoking shaped peak response without affecting anti-RBD IgG half-life. A third mRNA vaccine dose increased peak antibody titers and prolonged half-life compared to the second dose. These findings underscore the diverse kinetics of SARS-CoV-2 antibody responses, which is influenced by immunization type/number and clinical factors.

COVID-19 Vaccinations, Infections, and Outcomes Among 784 People Living with HIV

INTRODUCTION

Variants of COVID-19 are responsible for 700 million infections and 7 million deaths worldwide. Vaccinations have high efficiency in preventing infection and secondary benefits of reducing COVID-19 hospital admissions, attenuating disease severity and duration of illness. Conflicting reports were published regarding COVID-19 among PLWH.

OBJECTIVE

The aim of this study was to evaluate COVID-19 morbidity, hospitalization, and the magnitude of immunological response to sequential BNT 162b2 mRNA vaccines in PLWH regarding demographic and clinical factors.

RESULTS

Our retrospective study included 784 PLWH who had at least one anti- SARS-CoV-2 antibody test between March 2021 and October 2021. Half of our patients (392) had CD4 cell counts above 500 cells/µL, 40.2% (315) had 200 < CD4 < 500 cells/µL and only 9.8% (77) had CD4 < 200 cells/µL at their last laboratory workup. The mean age was 50.2 ± 12.2 years. About 90% of our patients were given at least two doses of the BNT 162b2 Pfizer vaccines; about 60% received three doses of the vaccine. About a quarter of our patients (27.6%) had COVID-19 infection. Only six patients required hospital admission. All six patients recovered from COVID-19 infection. Titers of COVID-19 antibodies were lower for patients with CD4 cell counts of less than 200 cells/µL in the first, second, and third serological tests with statistical significance. In a multinomial logistic regression, the influence of other factors such as age, sex, and previous COVID-19 infection on first COVID-19 antibody titers was not significant.

CONCLUSIONS

PLWH are responsive to COVID-19 vaccines. As was expected, patients with higher CD4 cell counts had higher titers of COVID-19 antibodies and lower hospitalization rate. Age, sex, and previous COVID-19 infection did not significantly affect antibody titers according to our study. Larger prospective studies with control groups are needed to further characterize immunologic response to COVID-19 vaccination among PLWH.

Responses to Common Misconceptions Relating to COVID-19 Variant-Adapted mRNA Vaccines

The evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the waning of immunity over time has necessitated the use of booster doses of original coronavirus disease 2019 (COVID-19) vaccines. This has also led to the development and implementation of variant-adapted messenger RNA (mRNA) vaccines that include an Omicron sub-lineage component in addition to the antigen based on the wild-type virus spike protein. Subsequent emergence of the recombinant XBB sub-lineages triggered the development of monovalent XBB-based variant-adapted mRNA vaccines, which are available for vaccination campaigns in late 2023. Misconceptions about new variant-adapted vaccines may exacerbate vaccine fatigue and drive the lack of vaccine acceptance. This article aims to address common concerns about the development and use of COVID-19 variant-adapted mRNA vaccines that have emerged as SARS-CoV-2 has continued to evolve.

Evaluation of Covid-19 anti-spike IgG antibody five months after the second Covid-19 vaccination

Background

Studies in different communities have shown significant differences in IgG antibody titers in the time period after the first and second doses of the vaccines. This study aimed to serologically evaluate the IgG anti-spike antibody titer five months after injection of the second COVID-19 vaccine in healthcare workers.

Materials and method

This study was performed in healthcare personnel for whom five months had passed since their second anti-Covid-19 vaccination. The level of IgG antibody against SARS-CoV-2 spike protein was measured by ELISA. Healthcare workers in Mofid Children's hospital received three brands of vaccines: Sputnik V, Sinopharm, and AstraZeneca.

Results

The mean titer of anti-spike IgG was 4.3±2.29 units. The percentage of positive cases of the antibody was estimated to be 96.4%. The titer of anti-spike IgG antibody was dependent on both the occupational area and a positive history of Covid-19 disease.

Conclusion

About 96.4% of the staff vaccinated against Covid-19 had a high titer of anti-spike IgG antibody even five months after inoculation of the second dose. The field of occupational can affect the level of antibody present.