TY - GEN AU - Rella, Simon AU - Kulikova, Y AU - Minnegalieva, Aygul AU - Kondrashov, Fyodor ID - 14862 IS - Supplement_2 KW - Public Health KW - Environmental and Occupational Health SN - 1101-1262 T2 - European Journal of Public Health TI - Complex vaccination strategies prevent the emergence of vaccine resistance VL - 33 ER - TY - JOUR AB - Replication-incompetent adenoviral vectors have been extensively used as a platform for vaccine design, with at least four anti-COVID-19 vaccines authorized to date. These vaccines elicit neutralizing antibody responses directed against SARS-CoV-2 Spike protein and confer significant level of protection against SARS-CoV-2 infection. Immunization with adenovirus-vectored vaccines is known to be accompanied by the production of anti-vector antibodies, which may translate into reduced efficacy of booster or repeated rounds of revaccination. Here, we used blood samples from patients who received an adenovirus-based Gam-COVID-Vac vaccine to address the question of whether anti-vector antibodies may influence the magnitude of SARS-CoV-2-specific humoral response after booster vaccination. We observed that rAd26-based prime vaccination with Gam-COVID-Vac induced the development of Ad26-neutralizing antibodies, which persisted in circulation for at least 9 months. Our analysis further indicates that high pre-boost Ad26 neutralizing antibody titers do not appear to affect the humoral immunogenicity of the Gam-COVID-Vac boost. The titers of anti-SARS-CoV-2 RBD IgGs and antibodies, which neutralized both the wild type and the circulating variants of concern of SARS-CoV-2 such as Delta and Omicron, were independent of the pre-boost levels of Ad26-neutralizing antibodies. Thus, our results support the development of repeated immunization schedule with adenovirus-based COVID-19 vaccines. AU - Byazrova, Maria G. AU - Astakhova, Ekaterina A. AU - Minnegalieva, Aygul AU - Sukhova, Maria M. AU - Mikhailov, Artem A. AU - Prilipov, Alexey G. AU - Gorchakov, Andrey A. AU - Filatov, Alexander V. ID - 12131 JF - npj Vaccines KW - Pharmacology (medical) KW - Infectious Diseases KW - Pharmacology KW - Immunology KW - SARS-COV-2 KW - COVID SN - 2059-0105 TI - Anti-Ad26 humoral immunity does not compromise SARS-COV-2 neutralizing antibody responses following Gam-COVID-Vac booster vaccination VL - 7 ER -