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OpenTrials
Completed

NCT Number: NCT03598439

Randomized Influenza Vaccine Evaluation of Immune Response

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.

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Key information

Conditions

Influenza Infections Influenza, Human Orthomyxoviridae Infections RNA Virus Infections Respiratory Tract Diseases Respiratory Tract Infections Virus Diseases

Age range

18 year–64 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 4

Primary location

Marshfield Clinic - Marshfield Center

Marshfield, Wisconsin, 54449, United States

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • 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

Exclusion criteria

  • 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

Treatment and study plan

Standard IIV4

Biological

Standard inactivated influenza vaccine

Other names: Flulaval Quadrivalent

Recombinant

Biological

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

Other names: FluBlok Quadrivalent

Cell-culture

Biological

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

Other names: Flucelvax Quadrivalent

Primary outcomes

  1. Post-vaccination titer

    Time frame: 28 days

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

Sponsors and collaborators

Lead sponsor

Marshfield Clinic Research Foundation

Other

Collaborators

  • Centers for Disease Control and Prevention

Registry information

Official study 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)

Acronym: RIVER

Important dates

Study start
2018
Primary completion
2020
Study completion
2024
First posted
Jul 26, 2018
Registry last updated
Nov 21, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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