Merx, RaphaëlSuominen, HannaCohn, TrevorVylomova, Ekaterina2026-03-232026-03-239798891763418ORCID:/0000-0002-4195-1641/work/209075280https://hdl.handle.net/1885/733807686In machine translation (MT), health is a high-stakes domain characterised by widespread deployment and domain-specific vocabulary. However, there is a lack of MT evaluation datasets for low-resource languages in this domain. To address this gap, we introduce OpenWHO, a document-level parallel corpus of 2,978 documents and 26,824 sentences from the World Health Organization's e-learning platform. Sourced from expert-authored, professionally translated materials shielded from web-crawling, OpenWHO spans a diverse range of over 20 languages, of which nine are low-resource. Leveraging this new resource, we evaluate modern large language models (LLMs) against traditional MT models. Our findings reveal that LLMs consistently outperform traditional MT models, with Gemini 2.5 Flash achieving a +4.79 ChrF point improvement over NLLB-54B on our low-resource test set. Further, we investigate how LLM context utilisation affects accuracy, finding that the benefits of document-level translation are most pronounced in specialised domains like health. We release the OpenWHO corpus to encourage further research into low-resource MT in the health domain.We are deeply grateful to the World Health Organization (WHO) for their collaboration and for granting us permission to collect and publicly release the OpenWHO dataset. In particular, we would like to express our sincere gratitude to Heini Utunen, Corentin Piroux, and Melissa Attias for their support and guidance on this project. This research was supported by The University of Melbourne's Research Computing Services and the Petascale Campus Initiative.19enPublisher Copyright: © 2025 Association for Computational Linguistics.OpenWHO: A Document-Level Parallel Corpus for Health Translation in Low-Resource Languages202510.18653/v1/2025.wmt-1.8105028853372