OAS-nano: the Observed VHH Space Database

VHHs, the variable regions of camelid heavy-chain antibodies, are increasingly used as therapeutic, diagnostic, and research tools because of their small size and stability. Despite the growing number of publicly available VHH repertoire sequencing studies, there is no large-scale, web-accessible database of VHH sequences. Here, we present OAS-nano, a database containing over 73 million unique VHH sequences collected from 16 public repertoire sequencing datasets and 1 previously unpublished dataset, spanning alpaca, llama, and Bactrian camel repertoires. Sequence reads were processed using a standardized pipeline to extract high-quality VHH sequences. Experimental metadata and sequence annotations enable users to identify sequences appropriate for their use case. OAS-nano is freely available at https://oas-nano.opig.stats.ox.ac.uk/.