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

The CASPER also found that just less than half of households reported having at least one health symptom caused by the cross-border sewage crisis, such as headaches, nausea and dry throat. Most with chronic conditions, such as allergies, migraines, asthma and lung pain, said their symptoms have worsened.

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.

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.

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.

Senator Alex Padilla and Congressmembers Juan Vargas, Sara Jacobs, and Scott Peters requested the investigation.

The rise of bird flu across farms in California has raised questions about the virus and its potential threat to humans. While the threat to humans is currently small.