A virus without a vaccine or treatment is hitting California. What you need to know

The Seattle Times • March 5, 2026 • health

Key Points:

Human metapneumovirus (HMPV), a respiratory virus without a vaccine or specific treatment, is spreading in parts of California, with high levels detected in Northern California wastewater and low to moderate levels in Los Angeles County.
HMPV typically spreads seasonally from January to June, but its pattern was disrupted by the COVID-19 pandemic, leading to decreased natural immunity and increased vulnerability upon resumption of normal activities.
Symptoms of HMPV are generally mild and cold-like, but severe cases can lead to asthma attacks, ear infections, croup, bronchitis, or pneumonia, especially in young children, older adults, and immunocompromised individuals.
There is no specific treatment for HMPV;