A virus without a vaccine is spiking throughout California. Here’s what doctors say you need to know
Key Points:
- High levels of human metapneumovirus (HMPV), a seasonal flu virus that can cause pneumonia and bronchitis, have been detected in wastewater across Northern California, with the highest levels in Redwood City, San Francisco Bay Area, and Napa’s Wine Country.
- Nationally, HMPV cases have been increasing since October 2025, particularly in California and the Northeast coast, as the virus typically circulates during winter and spring months.
- HMPV symptoms resemble a common cold but can lead to serious complications such as middle ear infections, severe asthma attacks, and in rare cases, death among vulnerable populations like infants, the elderly, and immunocompromised individuals.
- Unlike flu and RSV, there are no vaccines for