Measles Cases Rise in California: Vaccination Urged

California is currently experiencing a rise in measles cases across multiple counties, prompting urgent calls for vaccination from public health officials. The California Department of Public Health (CDPH) is urging residents to check their immunization status and get vaccinated to protect themselves and their communities.

Recent Measles Activity in California

As of late February 2026, measles cases have been reported in Los Angeles, Orange, San Bernardino, Riverside and Shasta counties. Shasta County is experiencing an outbreak of eight related cases, marking the state’s first measles outbreak since 2020. All individuals affected were either unvaccinated or had an unknown vaccination history CDPH.

Why Measles is a Concern

Measles is a highly contagious viral infection that spreads through the air when an infected person coughs or sneezes. It can lead to serious complications, especially in young children and individuals with weakened immune systems. The United States is currently experiencing the highest number of measles cases in more than 30 years, largely due to declining vaccination rates CDPH.

The Importance of the MMR Vaccine

The most effective way to protect against measles is through vaccination with the measles, mumps, and rubella (MMR) vaccine. The MMR vaccine is typically administered in two doses:

• First dose: 12–15 months old
• Second dose: 4–6 years old

For those traveling internationally, it’s crucial to be fully vaccinated before departure. Infants 6–11 months old traveling internationally should receive one dose of the MMR vaccine before travel, with two additional doses administered after their first birthday CDC.

The MMR vaccine is generally effective for life, although immunity to mumps may decrease over time CDC. An alternative vaccine, MMRV, which also protects against varicella (chickenpox), is available for children aged 12 months through 12 years CDC.

Where to Find More Information

For more information on measles and vaccination guidance, please visit the following resources:

• California Department of Public Health – Measles
• Centers for Disease Control and Prevention – Measles Vaccination
• CDPH Vaccines for All

Key Takeaways

• Measles cases are rising in California and across the U.S.
• The MMR vaccine is the most effective way to prevent measles.
• Ensure you and your family are up-to-date on vaccinations.
• Contact your healthcare provider if you have concerns about measles or vaccination.