Randomized Influenza Vaccine Evaluation of Immune Response
Public ClinicalTrials.gov record NCT03598439. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.
Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.
Official title
Randomized Open-Label Trial to Compare Immunogenicity of Egg-Based and Non-Egg Based Quadrivalent Influenza Vaccines Among Adults 18-64 Years of Age (US Flu Vaccine Effectiveness Serologic Study, 2018-19 and 2019-20)
Brief summary
Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.
Licensed influenza vaccines are manufactured with a variety of technologies. The majority are split, inactivated vaccines derived from egg-adapted, high growth reassortant viruses. Two US licensed products do not use egg-adapted viruses: Flucelvax (mammalian cell culture) and FluBlok (recombinant). There is increasing evidence that egg propagation induces virus mutations that impair the immune responses to circulating viruses. However, the impact of egg-propagation on clinical vaccine effectiveness is uncertain, and there is no preferential recommendation for any specific influenza vaccine product or technology. A direct comparison of serologic response to egg based and non-egg based vaccines in adults has not been performed. This randomized trial will compare serologic responses to the egg- and non-egg A(H3N2) vaccine component. The study cohort will be followed for two influenza seasons to evaluate sequential vaccination effects on immune response.
Study identification
- NCT ID
- NCT03598439
- Recruitment status
- Completed
- Study type
- Interventional
- Phase
- Phase 4
- Enrollment
- 366 participants
Conditions and interventions
Conditions
Eligibility (public fields only)
- Age range
- 18 Years to 64 Years
- Sex
- All
- Healthy volunteers
- Healthy volunteers not accepted
This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.
Study timeline
- Start date
- Jul 29, 2018
- Primary completion
- Mar 17, 2020
- Completion
- Jul 8, 2024
- Last update posted
- Nov 20, 2025
2018 – 2024
United States locations
- U.S. sites
- 1
- U.S. states
- 1
- U.S. cities
- 1
| Facility | City | State | ZIP | Site status |
|---|---|---|---|---|
| Marshfield Clinic - Marshfield Center | Marshfield | Wisconsin | 54449 | — |
Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.
About this trial record page
- What this page shows
- Public field values for ClinicalTrials.gov record NCT03598439, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
- What this page does not do
- No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
- Where the data comes from
- Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
- Last refresh
- Last update posted Nov 20, 2025 · Synced Sep 2, 2026
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Open the official record
The complete protocol, eligibility criteria, and contact information for NCT03598439 live on ClinicalTrials.gov.