Klingler et al.
May 7, 2024
This study examines the antibody responses elicited by the heterologous Ad26/Ad5 adenovirus-vectored vaccines against SARS-CoV-2, comparing them with LNP-mRNA vaccines and natural infection.
Klingler examines the antibody responses elicited by the heterologous Ad26/Ad5 adenovirus-vectored vaccines against SARS-CoV-2, comparing them with LNP-mRNA vaccines and natural infection. Key findings include:
Antibody Isotypes: Ad26/Ad5 vaccines predominantly generated IgG1 and IgG4 antibodies, while LNP-mRNA vaccines elicited a broader range of isotypes (IgM, IgG1-4, IgA1-2), and convalescent COVID-19 patients had a diverse range, including IgM, IgG1, IgG2, IgG3, and IgA1.
Neutralization Potency: Despite some waning of spike-binding antibodies over time (6 months), the Ad26/Ad5 vaccine maintained neutralization titers against early SARS-CoV-2 variants (Wuhan, Alpha, Beta, Delta). There was no significant decline in neutralization potency over time.
Fc-Mediated Functions: The Ad26/Ad5 vaccine-induced antibodies showed stronger Fc-mediated activities, such as complement activation and antibody-dependent cellular phagocytosis (ADCP), compared to those from convalescent patients. The LNP-mRNA vaccines also elicited strong Fc responses but not as potent as Ad26/Ad5.
Fc Functions and Protection: Fc-mediated functions are critical for immune responses, and these vaccine-induced antibodies showed greater capacity for complement binding and Fc receptor activation than those from natural infection.
In conclusion, the Ad26/Ad5 vaccines generated potent antibody responses with enhanced Fc functions, suggesting their potential utility in providing long-term protection against SARS-CoV-2, even as neutralization titers for certain variants decreased over time.
https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2024.1382619/full