Once Zika virus arrives in the United States, it will be here to stay. Leading experts now predict that the mosquito-borne disease will become a constant low-level threat that Americans will need to be vaccinated against routinely—as we do now for rubella, a virus that, like Zika, causes birth defects.

That is, once there is a vaccine for Zika. The earliest possible deployment of Zika vaccines could be several years away, researchers from around the globe predicted at an Atlanta conference Tuesday, the annual meeting of the Global Virus Network.

Overall, they said, Zika should be understood not as an epidemic wave that will pass over the world and then vanish, but rather as a permanent problem