Vaccine · California
Vaccine studies in California
36 studies have at least one recruiting site in California. Vaccine trials test how well new or updated vaccines produce an immune response and how they are tolerated. Many recruit healthy adults; some focus on older adults, children or people with specific conditions.
36 recruiting studiesSource: ClinicalTrials.gov, refreshed October 26, 2026How we list studies
Studies
- RecruitingPhase 1/Phase 2
Study to Evaluate Safety, Efficacy and Immunogenicity of Acne mRNA Vaccine in Adults With Moderate to Severe Acne
Sanofi Pasteur, a Sanofi Company
- Location
- Cerritos, CA + 78 other US sites
- Eligibility basics
- Ages 18–45
- RecruitingPhase 1/Phase 2
Study to Evaluate Safety, Efficacy and Immunogenicity of Acne mRNA Vaccine in Participants With Mild Acne
Sanofi Pasteur, a Sanofi Company
- Location
- Encino, CA + 3 other US sites
- Eligibility basics
- Ages 18–45
- RecruitingPhase 1
A Study on the Safety and Immune Response of Investigational mRNA Seasonal Flu/COVID-19 Combination Vaccine in Adults
GlaxoSmithKline
- Location
- Fair Oaks, CA + 11 other US sites
- Eligibility basics
- Ages 65–85
- RecruitingHealthy volunteersPhase 2
CMV-MVA Triplex Vaccination in HLA-Matched Related Stem Cell Donors for the Prevention of CMV Infection in Patients Undergoing Hematopoietic Stem Cell Transplant
City of Hope Medical Center
- Location
- Duarte, CA + 2 other US sites
- Eligibility basics
- Ages 18–75
- RecruitingHealthy volunteers
Effect of Messaging on Pragmatic Outcomes Within an Integrated Healthcare System
Kaiser Permanente
- Location
- Pasadena, CA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
HPV Ends Here: Increasing Uptake of the HPV Vaccine
University of California, Davis
- Location
- Sacramento, CA
- Eligibility basics
- Ages 10–12
- RecruitingHealthy volunteers
Fluad vs. Fluzone High-Dose Vaccine Effectiveness Among Adults ≥65 Years
Kaiser Permanente
- Location
- Oakland, CA
- Eligibility basics
- Ages 65+
- RecruitingHealthy volunteers
Understanding Immunity to the Flu Vaccine in COVID-19 Patients
Stanford University
- Location
- Palo Alto, CA
- Eligibility basics
- Ages 9–64
- RecruitingHealthy volunteersPhase 4
Safety of RSV Preventive Monoclonal Antibody
Duke University
- Location
- Oakland, CA + 4 other US sites
- Eligibility basics
- Ages 1 mo–7 mo
- RecruitingHealthy volunteers
A Study to Evaluate Community-Based Measures to Increase RSV Vaccine Use Among Latino Adults
University of California, San Francisco
- Location
- San Francisco, CA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
Vaccine Confidence and Infodemic in Southeast Asia's Nusantara Sociocultural Sphere
University of California, Berkeley
- Location
- Berkeley, CA
- Eligibility basics
- Ages 18+
- RecruitingHealthy volunteers
Researchers At UC San Diego Are Learning About the Benefits of Human Milk and How It Influences Infant and Child Health
University of California, San Diego
- Location
- San Diego, CA
- Eligibility basics
- Ages 18+ · Women only
Who these studies look for
Vaccine studies often exclude people who recently received a related vaccine or had the infection, and those with conditions or medicines that affect the immune system.
Matching a page like this one never means you qualify. Each research team decides eligibility at screening.
Questions
Could I receive a placebo?
Often yes. Many vaccine trials are randomized, so some participants receive a comparison vaccine or placebo. The consent document explains this.