Vincent and Rich recorded this episode at Vaccines in the 21st Century, a meeting held at the University of California, Irvine, where they spoke with Stacy Schultz-Cherry, Douglas Diekema, and Andrew Noymer about vaccine facts and fiction.
There is currently no vaccine to prevent infection with herpes simplex virus type 1 or type 2 (HSV-1 or HSV-2). Infection with either of these viruses results in life-long viral latency. Sporadic reactivation and viral shedding may lead to painful oral and genital disease and an increased risk of HIV transmission.
Vincent, Kathy, and Alan review the ongoing outbreak of Ebola virus in the Democratic Republic of the Congo, and the finding that mutations identified in the 2015 West African epidemic do not alter pathogenesis in animals.
Scott Hensley of the University of Pennsylvania helps us summarize the current influenza season so far. Bottom line: it’s a very serious season with a great deal of morbidity and mortality. As usually, serious disease and deaths occur in unvaccinated individuals. Although there is a mismatch between the influenza vaccine and this year’s H3N2 strain, which is causing most of the infections, vaccination still reduces disease severity cause by this strain, as well as by the circulating H1N1 and influenza B viruses. Next we discuss an interesting study of symptomatic college students with influenza. The goal was to determine which mode of influenza transmission is likely to be important: contact, or aerosols produced by speaking, coughing, or sneezing. The results show that simple breathing leads to virus in the breath – small aerosols that can travel distances to infect others. Coughing, but not sneezing, was a major observed sign of infection, but neither was needed for infectious aerosol generation.
The influenza virus vaccine is frequently updated to ensure that it protects against infection with circulating virus strains. In some years the vaccine matches the circulating strains, but in others, there is a mismatch. The result is that the vaccine is less effective at protecting from infection. During the 2014-15 influenza season there was a mismatch due to growing the vaccine in embryonated chicken eggs.