Viral fitness is an active area of research, with recent work involving an expanded number of human, non-human vertebrate, invertebrate, plant, and bacterial viruses. Many publications deal with RNA viruses associated with major disease emergence events, such as HIV-1, influenza virus, and Dengue virus. Study topics include drug resistance, immune escape, viral emergence, host jumps, mutation effects, quasispecies diversity, and mathematical models of viral fitness. Important recent trends include increasing use of in vivo systems to assess vertebrate virus fitness, and a broadening of research beyond replicative fitness to also investigate transmission fitness and epidemiologic fitness. This is essential for a more integrated understanding of overall viral fitness, with implications for disease management in the future.
Highlights
► Most viral fitness work examines replicative fitness within hosts or in cultured cells. ► There is increasing study of transmission fitness and epidemiologic fitness. ► A wide diversity of viruses are studied for fitness in vitro, in vivo, and ex vivo. ► A recent advance for vertebrate viruses is more assessment of fitness in vivo. ► Major topics include fitness in drug resistance, immune escape, and viral emergence.
