According to the mashable article [1] linked in the comments one component of the serum had some extended protection in a series of tests:
"A November 2013 Defyrus study showed that ZMAb offered extended protection against the virus. Scientists reinfected surviving monkeys 10 weeks after their first infection, and 100% survived. What's more, four out of the six monkeys reinfected 13 weeks after initial exposure survived."
Comments
According to the mashable article [1] linked in the comments one component of the serum had some extended protection in a series of tests:
"A November 2013 Defyrus study showed that ZMAb offered extended protection against the virus. Scientists reinfected surviving monkeys 10 weeks after their first infection, and 100% survived. What's more, four out of the six monkeys reinfected 13 weeks after initial exposure survived."
[1] http://mashable.com/2014/08/17/ebola-serum-zmapp/