(Santa Ana, CA) – The OC Health Care Agency (HCA) received confirmation of a measles case in an infant who had history of international travel. The HCA is notifying individuals who were exposed to the person in health care and other settings.
“Measles is highly contagious. Anyone planning domestic or international travel—or hosting visitors—should be fully vaccinated at least two weeks beforehand. Infants less than a year old who are traveling internationally should receive one dose of MMR vaccine before departure. Adults and others who are not immune remain at risk, especially as outbreaks continue across the country and worldwide,” said Dr. Anissa Davis, Deputy County Health Officer. “Vaccination is the best protection.”
According to the Centers for Disease Control and Prevention (CDC), there have already been 1,792 confirmed measles cases in the United States in 2026. By comparison, 2025 saw 2,267 cases, the highest annual total in more than 30 years. This is the third case of measles in Orange County in 2026.
Common symptoms include fever, cough, red watery eyes, and a rash that typically begins on the head before spreading to the rest of the body. Measles is the most contagious disease known, and it spreads very easily through the air and by direct contact with an infected person. People are contagious from approximately four days before the rash begins through four days after the rash appears.
Anyone who suspects they may have measles should call their medical provider before arriving at the medical office to avoid exposing others. Clinicians should immediately report any suspected measles cases to the OC Health Care Agency for guidance and testing coordination.
Vaccination remains the most effective way to prevent measles. About measles immunization:
- Immunizing household members, including children, adolescents, and adults, is the best way to protect infants who are too young to receive the MMR vaccine.
- Infants should receive their first MMR vaccine at 12-15 months of age. The second dose of MMR is given between 4 and 6 years of age, before starting school.
- Measles is found in many parts of the world, including Europe, Asia, Africa, and the Middle East.
- Children 6 to 12 months of age who are traveling internationally are recommended to receive a dose of the MMR vaccine prior to travel, to decrease their risk of infection. Before travel to domestic measles outbreak areas talk to a health care provider about following immunization recommendations for international travel.
- Children 12 months and older, as well as adults, should receive two doses, at least 28 days apart, before travel if not already vaccinated.
For more information about measles, visit: https://www.cdph.ca.gov/Programs/CID/DCDC/Pages/Immunization/measles.aspx or www.ochealthinfo.com/measles.
For additional resources: health corner article: https://ochealthinfo.com/health-corner/together-we-can-prevent-measles-orange-county
ABOUT THE OC HEALTH CARE AGENCY
The OC Health Care Agency (HCA) is a regional interdisciplinary health jurisdiction and an accredited health department, charged with protecting and promoting individual, family and community health through partnership and coordination of public and private sector resources.
Visit www.ochealthinfo.com to learn more about services and resources.
California is currently experiencing its highest number of annual measles cases in seven years, with 46 confirmed cases reported as of late April 2026. This significant surge follows several years of relatively low activity and mirrors a larger nationwide increase.
Recent Measles Case History in California
Measles cases in California have risen sharply since 2023, largely driven by international travel and localized outbreaks:
- 2026 (Year-to-Date): 46 confirmed cases as of late April.
- 2025: 25 confirmed cases.
- 2024: 15 confirmed cases.
- 2023: 4 confirmed cases.
The current 2026 total already surpasses the yearly totals for 2023, 2024, and 2025 combined.
Vaccination Rates in California
While California maintains some of the nation’s highest overall vaccination rates, there has been a slight downward trend recently:
- Statewide Coverage: For the 2024-2025 school year, approximately 96.1% of kindergarteners were fully vaccinated with the MMR vaccine.
- Unvaccinated Percentage: Roughly 3.9% of kindergarteners in California have not completed their measles vaccination series.
- Pockets of Risk: Despite high state averages, 16 counties have fallen below the 95% threshold required for herd immunity. In some areas like Sutter County, the rate is as low as 75.8%.
Experts from the California Department of Public Health note that about 95% of recent cases have occurred in individuals who were unvaccinated or had unknown status.
Individuals Who May Need a Measles Booster or Additional Dose
The CDC and other health organizations recommend checking your status or getting a booster if you fall into these categories:
- Vaccinated Between 1963 and 1967: Some people during this window received an “inactivated” or “killed” vaccine that was found to be ineffective. Unless you have proof of receiving the live vaccine, a booster with the current MMR is recommended.
- Only One Childhood Dose: Many adults born between 1968 and 1989 only received one dose before the two-dose schedule became standard in 1989. While one dose is 93% effective, a second dose (97% effective) is often advised for those in high-risk scenarios.
- High-Risk Occupations or Settings:
- Healthcare workers: Due to potential exposure and the risk of transmitting it to vulnerable patients.
- College students: Living in high-density student housing increases transmission risks.
- International Travelers: Anyone traveling outside the U.S. should ensure they have two documented doses.
- Close Contacts of the Immunocompromised: Boosting your own immunity helps protect those who cannot be vaccinated themselves.
- During Local Outbreaks: Local health departments may recommend an extra dose for everyone in an affected community to stop the spread.
Who is Likely Already Protected?
- Born Before 1957: Most adults in this age group are presumed immune because the disease was so widespread before the vaccine was introduced that nearly everyone contracted it as a child.
- Two Documented Doses: If you have records showing you received two doses of the live vaccine after your first birthday, you are generally considered protected for life.
If you are unsure of your status, you can request a titer test (blood test) from your doctor to check for antibodies, though health experts note there is no harm in simply getting another MMR shot if your immunity is in question.