Ongoing evolution of Middle East Respiratory Syndrome Coronavirus, Kingdom of Saudi Arabia, 2023-2024

Middle East respiratory syndrome coronavirus (MERS-CoV) circulates in dromedary camels in the Arabian Peninsula and occasionally causes spillover infections in humans. Due to lack of sampling during the SARS-CoV-2 pandemic, current MERS-CoV diversity is poorly understood. Of 558 dromedary camel nasal swabs from Saudi Arabia, sampled November 2023 to January 2024, 39% were positive for MERS-CoV RNA by RT-PCR. We generated 42 MERS-CoV and seven human 229E-related CoV by high-throughput sequencing. For both viruses, the sequences fell into monophyletic clades apical to the most recent available genomes. The MERS-CoV sequences were most similar to those from lineage B5. The new MERS-CoVs sequences harbor unique genetic features, including novel amino acid polymorphisms in the Spike protein. The new variants require further phenotypic characterization to understand their impact. Ongoing MERS-CoV spillovers into humans pose significant public health concerns, emphasizing the need for continued surveillance and phenotypic studies.