The hopes for a Zika vaccine are seemingly getting stronger by the day. To start, Harvard researchers have successfully tested two vaccine candidates in mice — reportedly the first instance of such a treatment working in an animal. One of them relies on an inert version of the virus, while the other entails customized DNA sequences. The scientists will need to test their work on larger animals before it’s declared safe, but it’s promising to see two more potential safeguards on top of one discovered just days earlier.
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.