Cases of human metapneumovirus, or HMPV, are hitting certain states, including California and New Jersey.
HMPV can cause upper and lower respiratory disease, and currently there is no vaccine to prevent it and no specific antiviral therapy to treat it, according to the Centers for Disease Control and Prevention.
Instead, medical care can be “supportive,” the CDC notes, which often involves treating symptoms. “Most people will recover on their own,” the agency notes, but adds people who get sick should drink plenty of liquids, stay home and rest.
The Cleveland Clinic says treatments for the virus can include oxygen therapy if the patient has a hard time breathing.
Here’s what else to know about the virus:
Is HMPV a new virus?
HMPV is not a “new” virus in 2026. It was first discovered in 2001, but cases haven’t spiked to recent levels in the U.S. since an April 2025 outbreak.
As of Feb. 21, the latest data available, HMPV makes up just over 5% of weekly reported positive tests for respiratory viruses, according to the National Respiratory and Enteric Virus Surveillance System, or NREVSS. This is up from 3.83% a week prior.
In April 2025, the weekly percentage peaked at 7.43%, the NREVSS data shows.
In New Jersey, the rise in HMPV cases, plus the number of RSV, COVID and flu cases, has led to the number of people seeking out emergency medical care to skyrocket, according to the New Jersey Department of Health.
In Northern California communities, high concentrations of HMPV have been detected in the wastewater, according to data from the WastewaterScan Dashboard, a public database that monitors sewage for infectious diseases.
HMPV symptoms
Symptoms of HMPV include cough, nasal congestion, fever and shortness of breath, according to the CDC. In some cases, these symptoms can progress to bronchitis or pneumonia.
Similar to the flu, HMPV is seasonal, meaning its circulation starts in winter and lasts through spring.
HMPV’s incubation period can be three to six days, according to the CDC, and the groups at highest risk include younger children and adults 65 or older.
HMPV prevention
While there is no specific treatment or vaccine for HMPV, there are steps you can take to help prevent infection.
Since the virus can be spread from person to person or through surfaces, the CDC suggests following core prevention strategies for respiratory viruses, including:
Washing hands properly
Avoiding touching eyes, nose or mouth with unwashed hands
Avoiding close contact with people who are sick
Cleaning frequently-touched surfaces
Taking steps for cleaner air
And for those with cold-like symptoms, cover your mouth and nose when you cough or sneeze to prevent spread.
Contributing: Fernando Cervantes Jr., USA TODAY
This article originally appeared on USA TODAY: What to know about the virus with no vaccine, treatment hitting certain states
Reporting by Sara Moniuszko, USA TODAY / USA TODAY
USA TODAY Network via Reuters Connect
