Antibody response results of Pfizer/BioNTech vaccine in different immunocompromised groups

Abstract

Background: Immunization or vaccination represents the most efÏcacious strategy for halting and controlling the dissemination of infectious diseases, including the Coronavirus Disease 2019 (COVID-19) pandemic. As of August 16, 2021, 62.7% of Mongolia’s adult population have received evidence of two doses of vaccination. Additionally, 5,688,144 vaccine doses were administered by March 16, 2023, underscoring the urgency in assessing specific antibody content. Research indicates an augmented risk of COVID-19 complications among individuals with underlying medical conditions. Specifically, populations undergoing immunosuppressive therapy for autoimmune diseases, chemotherapy and radiation therapy for cancer, and individuals infected with the human immunodeficiency virus (HIV) have been prioritized for COVID-19 Pfizer-BioNTech vaccination. Aim: To compare S-RBD-specific antibody levels among distinct groups with underlying diseases following two doses COVID-19 Pfizer-BioNTech vaccination Objectives: 1. Conduct a comparative analysis of post-vaccination S-RBD IgG antibody formation in immunosuppressed and immunodeficient populations 2. Examine post-vaccination S-RBD IgG antibody levels concerning additional doses Materials and Methods: The study encompassed three population groups: individuals receiving chemotherapy for cancer, those undergoing immunosuppressive treatment due to autoimmune diseases, and individuals infected with HIV. SARS-CoV-2 S-RBD (receptor binding domain) IgG specific antibody levels were detected using Anti-SARS-CoV-2 S-RBD protein Human IgG (Proteintech®, USA) ELISA kit. Enzyme-linked immunosorbent assays were employed for the analysis involving 168 subjects, of which 75 received a booster dose of the Pfizer/BioNTech vaccine, while 93 did not. Results: The concentrations of S-RBD IgG antibodies in three group subjects were 0.12±0.08 ng/mL (CI95: 0.02-0.21) before vaccination, 176.9±58.9 ng/mL (CI95: 167.9-185.8) 21-28 days after the two doses, and 201.6±61.1 ng/mL (CI95: 192.3-210.9) after 18 months. Statistical analysis revealed a significant difference in S-RBD IgG antibody concentration between genders and immunocompromised groups (p<0.0001), with no age group-specific disparities observed (p>0.05). The concentration of IgG antibodies formed within 21-28 days after vaccination was notably higher in the cancer group, a trend that persisted at the 12-18 months interval (p<0.0001). Conversely, the lowest concentration of S-RBD IgG antibody was identified in the group with HIV infection or immunodeficiency (p<0.0001). A total of 75 subjects participated in the study, including 37 with HIV, 8 with cancer, and 30 with HIV. Post-vaccine S-RBD IgG antibody levels were assessed in relation to additional doses. The tumor group exhibited the highest concentration of S-RBD IgG antibodies at 21-28 days after two doses of the vaccine and at 12-18 months after three doses (p<0.009). Conversely, at 12-18 months after three doses of the vaccine, the HIV-infected or immunocompromised group demonstrated the lowest concentration of S-RBD IgG antibodies (p<0.009). Importantly, the concentration of antibodies after 12-18 months was found to be higher (p<0.009) in all three groups compared to measurements at 21-28 days, suggesting the sustained preservation of antibodies produced by the additional vaccine dose over an extended period. Conclusions: 1. Antibody production in response to vaccination exhibits statistically significant variations based on gender and immunocompromised status. 2. In immunosuppressed and/or immunodeficient populations, antibody concentrations steadily increase and remain elevated following an additional vaccine dose.