January 22, 2026

This health advisory is being released to ensure all County of Santa Clara providers are up to date on local trends in vaccine preventable diseases and science-based vaccine guidance to protect patients.

Childhood and Adolescent Immunization Schedule

Situational Update

The County of Santa Clara Public Health Department strongly supports the evidence-based childhood and adolescent immunization schedule recommended by the American Academy of Pediatrics (AAP) and endorsed by the California Department of Public Health (CDPH) and West Coast HealthAlliance. Despite federal changes on January 5, 2026 overhauling the U.S. childhood immunization schedule, California’s recommended vaccine schedule remains unchanged, including immunization requirements for school and childcare entry. In September 2025, California state law was updated to ensure that our state’s immunization policies continue to align with evidence-based standards and the recommendations of professional medical groups like the AAP. Because you receive questions from families about conflicting national messages, clinicians play a crucial role in providing reassurance that vaccines remain recommended and covered by insurance in California.

Actions Requested of Providers

1. As trusted providers, continue recommending vaccines included in the AAP Child and Adolescent Immunization Schedule.
2. Continue to stock vaccines in your clinic so that patients do not need to go elsewhere to receive vaccines.
3. Proactively address patient questions. 

   • There are no new data to suggest that the AAP immunization schedule is unsafe or ineffective.

   • The infectious diseases that these vaccines protect against continue to circulate and pose a risk to health.

   • All vaccines recommended as of December 31, 2025, remain available and covered by public and private insurers in California including via the federal Vaccines for Children (VFC) program.

Measles Cases and Outbreaks in the Bay Area and the United States

Situational Update

In the last 30 days, there have been 4 cases of measles reported in neighboring counties in the Bay Area. Nationally, there were 2,242 measles cases reported in 2025. Of the 171 cases reported thus far in 2026 in the U.S., none were reported in international visitors, 96% are outbreak associated, and 95% occurred in unvaccinated individuals or those with unknown or unverified vaccination status. There are ongoing outbreaks in multiple areas of the United States, increasing the risk of domestic travel. There are also several upcoming large events in the Bay Area, including Super Bowl and FIFA World Cup. Collectively, these data underscore the importance of ensuring local residents are vaccinated and providers are prepared to respond to measles exposures.

Actions Requested of Providers

1. Ensure all individuals 12 months and older are up to date on their MMR vaccine. See AAP (pediatric) and AAFP (adult) guidelines for current vaccination recommendations.
2. Maintain a high clinical suspicion for measles in any individual presenting with fever and rash, regardless of history of international travel or vaccination status.
3. Review infection prevention protocols and ensure procedures are in place for rapid masking, isolation, and specimen collection of suspected measles cases. See our provider website for additional information on specimen collection and testing.
4. Ensure appropriate infection prevention personnel have been trained on measles contact investigationswithin a healthcare facility.
5. Immediately notify the Public Health Department of any suspected case of measles to ensure rapid testing and investigation. Call (408) 885-4214 and select option 3. After hours, call (408) 998-3438 and ask for the Health Officer on call.

Seasonal Influenza Vaccination, Testing, and Treatment

Situational Update

In Santa Clara, influenza vaccination rates are lower this year compared to previous years with only 35% of all Santa Clara County residents, and 57% of those aged 65 and older, vaccinated. Seasonal influenza levels remain high as of January 22, 2026, and it is not too late for patients to benefit from vaccination this season. The predominant circulating strain in the United States and in California is H3N2 subclade K. Early vaccine effectiveness data suggests that influenza vaccination remains an effective tool in preventing influenza-related hospitalizations this season.

Actions Requested of Providers

1. Administer 2025-26 influenza vaccine to anyone 6 months of age and older who has not yet received it this season.
2. Test symptomatic patients as quickly as possible. Use rapid molecular (nucleic acid amplification detection) tests for outpatients, and RT-PCR and other influenza molecular tests for hospitalized patients to confirm diagnosis and guide timely treatment. Influenza A positive hospitalized patients, especially those in the ICU, should have specimens sent for subtyping. 
3. Initiate antiviral treatment without delay and ideally at point of care. Do not delay treatment while waiting for test results if influenza is suspected in high-risk patients. Treat immediately with oseltamivir or single-dose baloxavir based on recommendations for use. Treatment with influenza antivirals decreases the risk of serious illness and hospitalization in those at higher risk for severe disease.
4. Stay aware of respiratory virus activity in your community by visiting the County of Santa Clara Respiratory Virus Dashboard this respiratory season.

Resources:

1. Recommended Child and Adolescent Immunization Schedule (American Academy of Pediatrics)
2. Recommended Adult Immunization Schedule (American Academy of Family Physicians)
3. Measles Cases and Outbreaks (Centers for Disease Control and Prevention)
4. Measles Healthcare Exposure Investigation Quick Sheet (California Department of Public Health)
5. Measles (County of Santa Clara Public HealthDepartment)
6. People at Increased Risk for Flu Complications(Centers for Disease Control and Prevention)
7. Respiratory Virus Data (County of Santa Clara Public Health Department)
8. Reportable Diseases and Conditions (County of Santa Clara Public Health Department)