Information on virus without vaccine or treatment affecting specific states

Health authorities report a rise in human metapneumovirus infections across several US states. The virus causes respiratory illness and currently has no vaccine or specific treatment. Experts advise supportive care and preventive measures to limit spread.

Health officials in the United States are reporting a noticeable rise in human metapneumovirus (HMPV) infections across several states, including California and New Jersey. The Centers for Disease Control and Prevention (CDC) has confirmed that HMPV is capable of causing both upper and lower respiratory tract illnesses. Currently, there is no approved vaccine to prevent infection, nor is there a specific antiviral medication to treat it.

Medical Management Focused on Supportive Care

The CDC emphasizes that treatment for HMPV is primarily supportive. This approach addresses the symptoms caused by the virus rather than targeting the virus itself. Most patients recover without requiring specialized medical intervention. Recommended supportive measures include maintaining adequate hydration by drinking fluids and remaining at home to rest and limit transmission. In cases where patients experience breathing difficulties, interventions such as oxygen therapy may be provided, according to guidance from the Cleveland Clinic.

History and Current Prevalence of HMPV

HMPV is not a newly discovered pathogen; it was first identified in 2001. Despite its earlier discovery, reported case numbers remained relatively low until an outbreak occurred in April 2025. Recent surveillance data indicate an upward trend. As of February 21, 2026, HMPV represented slightly over 5% of weekly reported positive tests for respiratory viruses, according to the National Respiratory and Enteric Virus Surveillance System (NREVSS). This represents an increase from 3.83% the previous week. During the April 2025 outbreak, HMPV cases reached a peak of 7.43% of weekly reported tests.

Regional Impact of HMPV

In New Jersey, the increase in HMPV cases coincides with ongoing occurrences of respiratory syncytial virus (RSV), COVID-19, and influenza, placing additional pressure on emergency medical services. The New Jersey Department of Health has reported elevated demand for healthcare resources as a result. In Northern California, high levels of HMPV have been detected in wastewater, indicating widespread community transmission. This data is monitored through the WastewaterScan Dashboard, a public platform that tracks sewage for infectious disease indicators.

Symptoms and Risk Groups

Symptoms of HMPV infection can include nasal congestion and shortness of breath. In some cases, the virus may lead to bronchitis or pneumonia. HMPV typically circulates seasonally from winter through spring, with an incubation period of three to six days. Groups at higher risk for severe illness include young children and adults aged 65 years or older.

Preventive Measures Against HMPV

Although no vaccine or specific treatment exists, the CDC recommends general measures to reduce the risk of infection, which are consistent with strategies for preventing other respiratory viruses. These include:

• Frequent and thorough handwashing
• Avoiding contact with eyes, nose, and mouth with unwashed hands
• Maintaining distance from individuals who are ill
• Regular cleaning of frequently touched surfaces
• Improving indoor air circulation where feasible

Individuals experiencing symptoms similar to a cold are encouraged to cover their mouth and nose when coughing or sneezing to prevent viral spread.

Sources:

• A virus without a vaccine or treatment is hitting California. What you need to know (Los Angeles Times)
• Highly contagious virus with no treatment spreading rapidly through western state (Fox News)
• Respiratory virus that can cause 'barking' cough detected in Stamford wastewater, data shows (CT Insider)
• What to know about the virus with no vaccine, treatment hitting certain states