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Volume 32, Number 8—August 2026
Dispatch
Isolation of Infectious Highly Pathogenic Avian Influenza A(H5N1) Virus from Fetal Bovine Serum, United States, 2025
Figure 3

Figure 3. Heat inactivation of highly pathogenic avian influenza A virus subtype H5N1 in FBS, United States, 2025. FBS samples (1-mL aliquots) were spiked (107 TCID50/mL) with bovine highly pathogenic avian influenza A (H5N1) virus TX2/24 strain (clade 2.3.4.4b, genotype B3.13) and heat treated at 56°C for 30 minutes by using a water bath. Virus titers determined by endpoint dilutions in Cal-1 cells and expressed as TCID50/mL. Data represents observations (dots) from 3 independent experiments overlayed with the mean (horizontal line) +SEM (whiskers). FBS, fetal bovine serum; TCID50, 50% tissue culture infectious dose.
1These first authors contributed equally to this article.