The seven human coronaviruses have all originated from spillover events from a variety of nonhuman animals, including bats, rodents, and camels. Recently isolated coronaviruses from humans appear to have originated in pigs and dogs. Three of 369 plasma samples collected between May 2014 and December 2015 in two schools in ...

Eradication of poliomyelitis appears to be on track: types 2 and 3 polioviruses have been declared eradicated, and in the past 12 months there have been just 338 cases of type 1 polio in Afghanistan and Pakistan. But there have also been 491 cases of polio caused by the type ...

by Gertrud U. Rey Herpes simplex viruses infect cells of the skin and mucous membranes, where they establish a lifelong persistent infection in sensory neurons. Sporadic reactivation and viral shedding may lead to painful oral and genital disease and a three to five-fold increased risk of HIV transmission. There is ...

During viral replication, defective genomes may arise that lack essential sequences. These so-called defective genomes cannot replicate unless they are in the same cell as a helper virus. Defective genomes play a role in modulating pathogenesis of respiratory syncytial virus in humans. Copy-back defective viral genomes (cbDVGs) of RSV arise ...

Early in the COVID-19 pandemic, SARS-CoV-2 genome variation appeared to be low, with an average of 10 base differences in the 30,000 base genome between any two isolates. Late in 2020, as many more people were infected, variants were isolated that had more changes than previously seen. A study of ...