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InfluenzaPhase 4RIVERNCT03598439

Randomized Influenza Vaccine Evaluation of Immune Response

A Phase 4 study testing Standard IIV4, Recombinant and Cell-culture in people with Influenza, run by Marshfield Clinic Research Foundation at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

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). Read more about this study

Who is it for?
Ages 18 to 64 years
Conditions the study is for
Influenza
What is being tested?
Standard IIV4, Recombinant and Cell-culture
Type of treatment
Vaccines
Could I receive a placebo?
No, everyone receives an active treatment
How many people
366 participants
Where
1 siteUnited States
Study dates
30 Jul 2018to 9 Jul 2024
Phase
Phase 4
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 64 years
  • All sexes
  • No healthy volunteers
  • Adult

Who may be able to join

  • Aged 18-64 years
  • Marshfield Clinic patients living in or around Marshfield, Wisconsin since July 2015
  • Willing and able to give informed consent and comply with study requirements

Who cannot join

  • Receipt of 2018-19 influenza vaccine prior to study enrollment
  • Known to be pregnant at the time of enrollment
  • Current participation or plans to participate in another clinical trial involving an experimental agent
  • Presence of a contraindication to influenza vaccination
  • Plans to relocate outside the geographic location in the next two years

Trial locations and contacts

1 site in 1 country.

United States1 site
  • Marshfield Clinic - Marshfield Center

    Marshfield, Wisconsin, 54449

Other trials in United States

About this study

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)

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.

Conditions
Influenza
Being tested
Standard IIV4, Recombinant, Cell-culture
Keywords
influenza vaccine, adults, Immune response
Medical subject headings
Influenza, Human

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Standard IIV4Biological

    Also called Flulaval Quadrivalent

    Standard inactivated influenza vaccine

  • RecombinantBiological

    Also called FluBlok Quadrivalent

    Influenza vaccine that uses a hemagglutinin protein manufactured in insect cells with a baculovirus vector

  • Cell-cultureBiological

    Also called Flucelvax Quadrivalent

    inactivated influenza vaccine manufactured using mammalian cell lines; current vaccine uses a cell-propagated H3N2 strain.

Study groups in NCT03598439
Study groupRoleWhat they receive
Recombinant (RIV4) Influenza VaccineExperimentalA single dose of licensed recombinant influenza vaccine will be given in each of two influenza seasons - one in 2018-19 and a second in 2019-20.
Receives: Biological: Recombinant
Cell-culture (ccIIV4) Influenza VaccineExperimentalA single dose of licensed cell-culture influenza vaccine will be given in each of two influenza seasons - one in 2018-19 and a second in 2019-20
Receives: Biological: Cell-culture
Standard (IIV4) Influenza VaccineActive comparatorA single dose of licensed standard influenza vaccine will be given in each of two influenza seasons - one in 2018-19 and a second in 2019-20.
Receives: Biological: Standard IIV4

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Post-vaccination titer

    geometric mean titers (as measured by microneutralization) to cell-grown A(H3N2) vaccine reference virus

    Measured: 28 days

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted26 Jul 2018
  2. Study start30 Jul 2018
  3. Primary completion18 Mar 2020
  4. Study completion9 Jul 2024

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 4
Primary purpose
Basic science
Allocation
Randomised
Intervention model
Parallel groups
Masking
None (open label)
Enrolment
366 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT03598439
Sponsor's protocol ID
MCL10218
Acronym
RIVER
Status last verified
Nov 2025
First submitted
16 Jul 2018
Last updated
21 Nov 2025
Results posted
No
Data monitoring committee
No
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
No

Questions about this trial

What is this clinical trial studying?

A Phase 4 study testing Standard IIV4, Recombinant and Cell-culture in people with Influenza, run by Marshfield Clinic Research Foundation at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 3 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 21 Nov 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Post-vaccination titer (time frame: 28 days). It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 21 Nov 2025.

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