An initial infection with dengue virus did not prime monkeys for an especially virulent infection of Zika virus, according to a study at the University of Wisconsin-Madison. Nor did a bout with Zika make a follow-on dengue infection more dangerous.
source https://www.lifetechnology.com/blogs/life-technology-news-blog/fear-of-more-dangerous-second-zika-dengue-infections-unfounded-in-monkeys