Prior to their development of the mRNA vaccine for Covid-19, Karikó and Weissman (Nobel Prize 2023) and colleagues used a novel mRNA vaccine, with base modifications created in their laboratory, to generate a protective Zika vaccine. 

From the abstract: “....Here we demonstrate that a single low-dose intradermal immunization with lipid nanoparticle-encapsulated nucleoside modified mRNA (mRNA-LPN), encoding the pre-membrane and envelope glycoproteins of a strain from the ZIKV outbreak in 2013, elicited potent and durable neutralizing antibody responses in mice and non-human primates....” In 2023 the full text of this paper was available from nature.com at this link.

Order of authorship in the original publication: Pardi....Karikō....Weissman.

(Thanks to Juan Weiss for this reference and its interpretation.)