Skip to main content
OpenTrials
Completed

NCT Number: NCT06716567

Maternal Determinants of Immunity to Influenza

The overall objective of the project is to determine the impact of pregnancy on the response to influenza immunization.

Completed

Looking for future studies?

Notify Me

Key information

Conditions

Vaccination; Infection Immunoglobulins Infections Influenza Influenza, Human Maternal-Fetal Relations Orthomyxoviridae Infections RNA Virus Infections Respiratory Tract Diseases Respiratory Tract Infections Virus Diseases

Age range

18 year–40 year

Sex eligibility

Female

Study type

Interventional

Phase

Phase 4

Primary location

CHU Saint-Pierre

Brussels, 1000, Belgium

About this study

The study compares immune responses to influenza vaccination between a group of pregnant women and a group of non-pregnant controls women. Specifically, the study has three aims:

  • To compare the quality of antibodies induced by influenza immunization in pregnant and non-pregnant women;
  • To identify immune predictors of vaccine responses in pregnant women and compare them to the determinants of vaccine responses in non-pregnant women;
  • To identify immune predictors of the transfer of maternal antibodies to the newborn following influenza immunization during pregnancy;

Who can participate

Healthy volunteers accepted: Yes

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

Inclusion criteria

  • Age over 18 and under 40 years.

Exclusion criteria

  • Grade III/IV anemia
  • Human Immunodeficiency Virus (HIV) infection
  • Active bacterial infection
  • Opportunistic infection (Tuberculosis, cytomegalovirus (CMV), toxoplasmosis, etc)
  • Inability to understand the nature and extent of the study and the procedures required
  • Current or recent use of immunosuppressive drugs (corticosteroids, anti-tumor necrosis factors (anti-TNF), methotrexate, etc)
  • Active neoplasia

Treatment and study plan

influenza vaccine

Biological

Alpharix-Tetra®, Vaxigrip Tetra® and Influvac Tetra® were used as influenza vaccines in the 2020-2021, 2021-2022, and 2022-2023 seasons respectively.

Primary outcomes

  1. Haemagglutination Inhibition Assay titre

    Time frame: 28 days post vaccination

    Haemagglutination Inhibition Assay (HAI) titres are used to measure responses to relevant influenza strains. The HAI method exploits the property of the influenza virus to haemagglutinate red blood cells. HAI titres are determined as the highest serum dilution inhibiting haemagglutination. An HAI titre of >=40 is considered protective in adults.

    HAI titres will be measured in :

    • Pregnant women
    • Non-pregnant women

  2. Haemagglutination Inhibition Assay titre

    Time frame: At delivery

    Haemagglutination Inhibition Assay (HAI) titres are used to measure responses to relevant influenza strains. The HAI method exploits the property of the influenza virus to haemagglutinate red blood cells. HAI titres are determined as the highest serum dilution inhibiting haemagglutination. An HAI titre of >=40 is considered protective in adults.

    HAI titres will be measured in :

    • Pregnant women
    • In umbilical cord blood

Secondary outcomes

  1. Haemagglutination inhibition assay titre

    Time frame: up to 11 months after vaccination

    Haemagglutination Inhibition Assay (HAI) titres are used to measure responses to relevant influenza strains. The HAI method exploits the property of the influenza virus to haemagglutinate red blood cells. HAI titres are determined as the highest serum dilution inhibiting haemagglutination. An HAI titre of >=40 is considered protective in adults.

    HAI titres will be measured in :

    • Pregnant women: at day of vaccination, day 7 post-vaccination, day 28 post-vaccination, at delivery, week 6 and 12 post-delivery
    • Non-pregnant women: at day of vaccination, day 7, day 28, and Month 6 post-vaccination

  2. Micro neutralization assay titre

    Time frame: up to 11 months after vaccination

    Micro neutralization assay (MNA) titres are measured on serum samples with detectable HAI titres to determine cross reactivity to related virus strains. This method assesses the ability of serum antibodies to prevent virus from infecting a single layer of cells in a micro titre plate.

    MNA titres will be measured in :

    • Pregnant women: at day of vaccination, day 7 post-vaccination, day 28 post-vaccination, at delivery, week 6 and 12 post-delivery
    • Non-pregnant women: at day of vaccination, day 7, day 28, and Month 6 post-vaccination

  3. Influenza virus specific IgG titre

    Time frame: up to 11 month after vaccination

    IgG titres specific to influenza virus Hemagglutinin (HA) and Neuraminidase (NA) are measured using conventional Enzyme-linked immunosorbent assay (ELISA) methods. The Enzyme-Linked Lectin Assay (ELLA) is used for detection of NA-specific antibodies only, using reverse genetics viruses with irrelevant HA to ensure only NA antibodies are measured. ELLA is an ELISA variant but adapted to measure the concentration of antibody to NA, determining the amount of sialic acid cleaved from fetuin.

    IgG titres specific to Influenza Antigens will be assessed by ELISA and ELLA in:

    • Pregnant women: at day of vaccination, day 7 post-vaccination, day 28 post-vaccination, at delivery, week 6 and 12 post-delivery
    • Non-pregnant women: at day of vaccination, day 7, day 28, and Month 6 post-vaccination

  4. Influenza virus specific IgG antibody avidity

    Time frame: up to 11 months after vaccination

    IgG avidity will be measured using chaotropic salts.

    IgG avidity will be assessed in :

    • Pregnant women: at day of vaccination, day 7 post-vaccination, day 28 post-vaccination, at delivery, week 6 and 12 post-delivery
    • Non-pregnant women: at day of vaccination, day 7, day 28, and Month 6 post-vaccination

Sponsors and collaborators

Lead sponsor

Centre Hospitalier Universitaire Saint Pierre

Other

Collaborators

  • Université Libre de Bruxelles

Registry information

Official study title

Maternal Determinants of Immunity to Influenza (MADI-01)

Acronym: MADI-01

Important dates

Study start
2020
Primary completion
2023
Study completion
2023
First posted
Dec 4, 2024
Registry last updated
Mar 24, 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.

Related clinical trials

Published trials that share one or more normalized conditions with this study.