Persistent Viral Infections as Models for Research in Virus Chemotherapy

The acute systemic virus infection is commonly used as an experimental model in chemotherapy research despite the fact that the chance for an effective chemotherapy of acute virus infections is small. In most acute infections, virus multiplication is well advanced before the disease is expressed and treatment will, in many cases, come too late. However, control by chemotherapy might be promising for persistent virus infections, where, owing to the slow progression of the disease, sufficient time for treatment is available. Although there are various ways in which viruses can persist in their hosts, comparative studies in vitro and in vivo reveal common features that shall be briefly reviewed. Animal models with persistent virus infections are usually difficult to experiment with because of the varying length of the incubation period brought about by the complex relationship among virus replication, immune reactions, and disease.