Poxiviruses

Poxviruses are a family of large, complex viruses that infect animals. They are characterized by their brick-shaped or ovoid virions, which are among the largest and most complex of all viruses. The poxvirus genome consists of a single molecule of double-stranded DNA.

Members of the Poxviridae family are known for causing a variety of diseases, some of which have historically been significant public health concerns. The most famous example is the variola virus, the causative agent of smallpox, a disease that ravaged human populations for centuries before being eradicated through a global vaccination campaign. Other well-known poxviruses include the vaccinia virus, which was used to develop the smallpox vaccine and is also used in gene therapy and as a vector for other vaccines, and the molluscum contagiosum virus, which causes a common, self-limiting skin infection.

Poxviruses replicate in the cytoplasm of host cells, a feature uncommon among DNA viruses. They achieve this by carrying all the necessary enzymes for transcription and replication within the virion. Transmission typically occurs through direct contact with infected individuals or contaminated materials, or via respiratory droplets. While some poxviruses have been successfully eradicated or are largely controlled, others continue to circulate in animal populations and can occasionally spill over to humans, posing potential zoonotic threats. Research into poxviruses continues to advance our understanding of viral replication, immunity, and the development of novel therapeutic strategies.