Homann Perez*

ABSTRACT

The immune system maintains physiological balance by defending the body against a wide range of viral pathogens. To eliminate invading viruses, the host relies on coordinated innate, adaptive and complement-mediated responses. These immune pathways contain specialized sensors capable of recognizing foreign particles and initiating targeted defensive actions that restrict viral replication. Antiviral antibodies are central to this process, as they neutralize viruses and limit their ability to spread. However, in certain situations, antibodies that are typically protective may paradoxically support viral entry and replication within susceptible cells. This phenomenon, known as antibodydependent enhancement (ADE), occurs when virus–antibody complexes interact with Fc or complement receptors on host cells, facilitating internalization and influencing downstream immune responses. Such altered signaling can accelerate viral multiplication and intensify disease severity. Because of this potential risk, understanding ADE remains critical during the development of vaccines and antibody-based therapeutics, particularly for emerging viruses such as SARS-CoV-2. Keywords: SARS-CoV-2; Antibody-dependent enhancement (ADE); Vaccine safety; Neutralizing antibodies; Non-neutralizing antibodies; Immune response; ACE2 receptor; Fc receptor.