Whole virion antigen (WVA)

Whole virion antigen refers to the use of an entire virus particle as the active immunogenic component in a vaccine, rather than a specific isolated protein or molecular subunit. This approach involves either inactivating the virus using chemical or physical means (e.g., formaldehyde or UV light) or weakening it through serial passage to create a live-attenuated version (Plotkin's Vaccines, 7th Ed, 2017). Because the entire virion is present, the host immune system is exposed to all viral structural proteins, which typically results in a broad, polyvalent immune response involving both humoral and cellular pathways (WHO, Vaccine Types, 2021). In pharmacological databases like ChEMBL, the phrase "No specific molecular drug-like target virion used as antigen" is frequently used as a placeholder for vaccines where a single molecular target (such as a specific enzyme or receptor) cannot be defined because the entire viral assembly serves as the therapeutic agent (ChEMBL Database, Target Report Card). This method has been foundational in the development of vaccines for polio, influenza, and more recently, certain COVID-19 vaccines like CoronaVac (Gao et al., Science, 2020).

Other names

Inactivated virusLive-attenuated virusWhole virus vaccineViral particleWhole-cell antigen

Induction of active immunity by presenting the entire structural repertoire of a pathogen to the host immune system, stimulating B-cell and T-cell responses.