We're learning more about how the virus works, too. Another study (this time with rhesus monkeys) has revealed that a prior Zika infection will help protect you against subsequent viruses, and that the virus lasts longer in your blood if you're pregnant. That's possibly due to the pregnancy compromising your immune system, making it harder to fight back. The findings could not only help create a vaccine, but explain why Zika has been so dangerous in Brazil despite lingering in Africa for years -- Africans may just be exposed early enough that it's not an issue when pregnancy becomes an option. That, in turn, raises hope that Zika will eventually lose its potency in the Americas.