Virologie

Virology is the scientific discipline that studies viruses and virus-like agents. It encompasses their structure, classification, evolution, replication, host range, and the diseases they cause, as well as the methods used to detect, prevent, and treat viral infections. Virology intersects microbiology, immunology, molecular biology, and public health, reflecting the interdisciplinary nature of understanding viruses in nature and society.

Historically, virology emerged in the late 19th century with the discovery that certain infectious agents could pass through filters believed to trap bacteria. Dmitri Ivanovsky and Martin Beijerinck described tobacco mosaic virus, establishing the existence of filterable pathogens. The field grew with studies of bacteriophages, advances in electron microscopy, and later molecular techniques that revealed viral genomes and the distinct replication strategies of DNA and RNA viruses.

Viral diversity is organized by genome type, replication method, and host range. The Baltimore classification remains a common framework, grouping viruses into seven classes based on genome composition and transcription strategy. All viruses are obligate intracellular parasites, relying on host cells to replicate. The viral life cycle typically involves attachment to a receptor, entry, genome replication, assembly of new virions, and release.

Research and clinical practice in virology include diagnostics, vaccine development, and antiviral therapies. Techniques used to study viruses range from cell culture and electron microscopy to serology, polymerase chain reaction, and genome sequencing. Biosafety and ethical considerations guide work with pathogenic viruses and animal hosts.

Viruses influence health, ecosystems, and biotechnology. Some viruses cause diseases in humans and animals; others are used in gene therapy or as vectors for vaccines. Public health measures—surveillance, vaccination, hygiene, and rapid outbreak response—are essential to managing viral threats and reducing transmission.