Nooruzzaman et al. (2025 preprint) evaluated the stability of highly pathogenic avian influenza (HPAI) A(H5N1) virus in raw milk cheese. Raw milk cheddar cheese inadvertently produced with naturally contaminated raw milk had infectious HPAI H5N1 virus identified by rRT-PCR and virus titrations in embryonated chicken eggs for up to 60 days. The authors also spiked raw milk at varying pH with HPAI virus to observe the pH-dependent survival of the virus during the cheese making process and 60 days of aging or curing at 4ºC. The cheese at pH 6.6 and 5.8 had infectious virus present throughout the cheese making process and aging. The raw milk whey and curd samples collected from the pH 5.0 cheese group did not have detectable infectious virus.