A Washington State resident has died after contracting H5N5 avian influenza, marking the first confirmed human infection of this variant worldwide, the state’s health department announced late Friday.
The patient, an older adult from Grays Harbor County, had underlying health conditions and owned a backyard flock of mixed domestic birds, which officials believe was the likely source of exposure.
Environmental samples from the property tested positive for H5N5, indicating transmission from either domestic poultry or wild birds.
Low Public Risk, No Sign of Human-to-Human Spread
Health officials emphasized that the risk to the general public remains low.
No other individuals linked to the case have tested positive.
The health department said:
- There is no evidence of person-to-person transmission.
- Close contacts of the patient are being monitored for symptoms.
- Individuals exposed to the backyard flock or its environment are also under observation.
H5N5 is a highly pathogenic avian influenza subtype that has circulated among wild birds globally but had never been detected in a human until now.
U.S. Cancels Over $700 Million in Funding for Moderna Bird Flu Vaccine
Separately, the U.S. government has canceled more than $700 million in funding tied to Moderna’s development of a human bird flu vaccine, the company confirmed.
The termination — announced on 29 May 2025 — includes:
- A $590 million contract awarded in January under the Biden administration to support late-stage development of a bird flu vaccine and expand clinical trials for up to five additional influenza subtypes.
- A prior $176 million HHS award to complete late-stage development of a pre-pandemic mRNA-based vaccine targeting H5N1.
Moderna’s shares remained stable in after-hours trading following the announcement.
The Department of Health and Human Services (HHS) had previously stated it was reviewing all vaccine contracts made under the previous administration.
