The flu vaccine is generally about 40% effective at completely preventing influenza, according to Blumberg. The flu vaccine protects against three strains of influenza, including two influenza A strains. It also protects against influenza B, which typically shows up later in the season, Blumberg said.

CDC confirmed a new human case of H5N1 in California. The recent case involves a child from San Francisco. CDC data reveals that California has been the worst affected by the ongoing bird flu outbreak with 38 of the total cases reported.

The Trump administration’s directive to halt external communications from federal health agencies raised concern Wednesday among Bay Area health experts and local agencies, who warned that the pause could have significant consequences for public well-being — especially amid ongoing threats like the H5N1 avian influenza,

The US CDC confirmed another case of avian influenza A(H5N1), or bird flu, in California, bringing the nationwide total of cases to 67.

Bird flu is a disease caused by avian influenza A viruses, according to the CDC. The virus mostly spreads between birds and dairy cows, but there have been 67 human cases of bird flu nationwide and one death tied to the infection since 2024, CDC records show.

The CDC has confirmed a new human H5N1 bird flu case in California, raising the US total to 67. Most cases involve farm workers exposed to sick animals. The CDC urges rapid testing, antiviral treatments,

The highly contagious outbreak of norovirus has sickened at least 28 people staying at a California wildfire evacuation shelter. Public health officials said the gastrointestinal illness has been detected among a group of people at the Pasadena Convention Center,

After the holiday season and an uptick in travel, California is seeing a rise in respiratory illnesses, prompting health experts to talk of a potential “quad-demic.” The term refers to the simultaneous spread of four major viruses: COVID-19,

A child in San Francisco who had red eyes and a fever had a probable case of H5N1 bird flu, according to the city’s Department of Public Health.

The U.S. Centers for Disease Control and Prevention (CDC) confirmed another human H5N1 avian flu case -- otherwise kno

First came the fires. Then, there was ash and contaminated water. Now, some survivors of the Southern California wildfires are dealing with outbreaks of norovirus and other stomach ailments at a shelter set up to help evacuees.

Flu season is here in California, but other illnesses are in full swing in the Golden State. Here are the symptoms and how long you're contagious.