The Ebola epidemic is scary and every effort is being made to squelch its spread. Among those efforts is the search for a human vaccine. One of the most promising vaccines under development requires the use of a livestock virus, specifically a weakened vesicular stomatitis virus (VSV). While the vaccine could save millions of human lives it could also increase infections in livestock through exposure to vaccinated people.
VSV affects horses, cows, swine, sheep, goats, llamas, and alpacas. Essentially it resembles foot and mouth disease (FMD) as it causes painful blisters in the mouth and on the foot, although it is less severe than FMD. In some animals the blisters will also appear on the sheath or udders. There is no treatment other than soft foods and pain control for the duration but infected animals generally recover within two weeks.
Compared to human recovery rates from Ebola, just about everyone considers the potential increase in livestock infections an acceptable trade-off especially since infected animals rarely die from VSV. Still the issue isn’t being taken lightly. The vaccine makers are weighing the potential impact and looking for ways to potentially curtail it.
When asked about the possibility of vaccinated humans spreading the disease to livestock, Charles Link Jr., CEO of NewLink, the makers of the vaccine, said in an interview with Science magazine: “It's a legitimate concern and we're looking at ways to evaluate that.”