The A-Virus (Armed Virus) is an incurable virus that infects females in Valkyrie Drive Mermaid. Unlike other viruses from any media, it does not kill the user/host in contact, but rather it gives supernatural magic/ability to use a weapon-transforming process known as "Drive".

Limitations Edit

According to Kasumi, the A-Virus was a non-lethal viral system that can only infect some girls.