Objective:

To explore the critical role of Fc-mediated inhibitory antibodies in enhancing the immune defense provided by vaccines against HIV and SARS-CoV-2.

Key Findings:

• Neutralizing antibodies (NAbs) are crucial for vaccine efficacy but may not be the only protective mechanism; Fc-mediated inhibitory antibodies also play a significant role.
• Fc-mediated inhibitory antibodies can counteract viral mutations and broaden the immune response, which is essential for effective vaccination.
• HIV-specific antibodies often lack functional inhibitory activity due to high mutation rates and immune evasion strategies, highlighting the need for innovative vaccine approaches.
• SARS-CoV-2 vaccines induce NAbs, but their protective efficacy diminishes with emerging variants, necessitating further investigation into Fc-mediated responses.

Interpretation:

Understanding the role of Fc-mediated inhibitory antibodies is essential for developing more effective vaccines against HIV and SARS-CoV-2, as traditional neutralizing antibody responses may not suffice, particularly in the face of evolving viral variants.

Limitations:

• Current knowledge on the mechanisms of Fc-mediated inhibition is limited, particularly regarding their in vivo relevance.
• The physiological relevance of in vitro assays for measuring antibody functions is unclear, necessitating more robust experimental designs.

Conclusion:

Further research is urgently needed to elucidate the mechanisms of Fc-mediated antibody functions to enhance vaccine design against HIV and SARS-CoV-2.