Imperfect vaccines could make viruses more dangerous, at least in chickens
July 27
The vaccines widely used by humans today -- especially those used to protect children against mumps, measles, and other potentially deadly ailments -- are what we'd call "perfect" vaccines. But new research suggests that "imperfect" or "leaky" vaccines -- ones that don't make their hosts totally immune to the disease and incapable of spreading it to others -- might have a surprising downside. For now, this so-called leakiness only exists in vaccines used to treat farm animals. But researchers warn that as humankind tackles bigger, badder diseases, we should keep the potential danger of leaky vaccines in mind.
http://www.washingtonpost.com/news/...-make-viruses-more-deadly-new-study-suggests/