California, flu and RSV

Experts warn of a ‘quad-demic’ as flu, RSV, COVID-19 and norovirus converge in California
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,
How effective is the flu vaccine amid California ‘quad-demic’? Is it too late to get shots?
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.
As the flu rises in California, the difference between COVID, RSV, Norovirus, influenza
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.
What to know about 'quad-demic' of COVID, flu, RSV and norovirus in US
The U.S. is seeing a "quad-demic" as cases of COVID-19, flu, RSV and norovirus spread at the same time. Experts said this is what you need to know.
Viral sicknesses rise amid ‘quad-demic’ in US
Viral sicknesses have risen in early 2025 amid the ongoing “quad-demic” in the U.S., referring to three respiratory viruses and one gastrointestinal disease, according to the Centers for Disease Control and Prevention (CDC) data.
CDC survey: Most living near Tijuana River say their health has worsened
The CASPER also found that just less than half of households reported having at least one health symptom caused by the ...
CDC begins investigation into health impacts of Tijuana River sewage crisis on San Diego communities
Senator Alex Padilla and Congressmembers Juan Vargas, Sara Jacobs, and Scott Peters requested the investigation.