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Active, not recruitingNCT06286488Updated Mar 1, 2024

Effectiveness and Tolerability of Influenza Vaccine in Patients at Risk for Severe and Complicated Influenza

A Phase 4 interventional study of Vaxigrip in Influenza, Obesity and Pregnancy; Infection, sponsored by Medical University of Warsaw. Active, not recruiting at 1 site in Poland. Open to participants aged 18 Years to 99 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2024-03-01.

Sponsored by Medical University of Warsaw · Phase 4, Interventional, and Prevention

From the registry’s dates

  • Registered 3 years 5 months after the study started (first participant enrolled Sep 2020, registered Feb 2024).
Phase
Phase 4
Study type
Interventional
Enrollment
1,500
Allocation
Non-randomized
Ages
18 Years to 99 Years
Sex
All
01

Study summary

The aim of the study is to evaluate simultaneously the immunological and clinical efficacy and tolerability of an influenza vaccine, inactivated, quadrivalent, with cleaved virus, in patients at risk for severe and complicated influenza routinely vaccinated against influenza in family medicine clinics or specialty clinics (pediatric, internal medicine, cardiology, gynecological diabetes, pregnant women, transplant).

Read the detailed description

Influenza has been called the last uncontrollable scourge of mankind because of its epidemic and pandemic potential. According to WHO estimates, 5-10% of the adult population and 10-20% of children globally fall ill with influenza seasonally. Influenza incidence has implications for individual patients (risk of complications, hospitalization, disability and death), as well as for public health (increased outpatient consultations, hospitalizations, including in intensive care units, increased absenteeism from work). Groups at risk for post-influenza complications include children under the age of 5, seniors over 65, patients with chronic diseases such as respiratory, cardiovascular, metabolic conditions, obesity, immunosuppressive treatment, and pregnant women, among others. Since the influenza A H1N1pdm09 pandemic, the WHO has particularly emphasized the need to vaccinate patients at risk of severe and complicated influenza, and has recommended a tetravalent vaccine since 2013. The inactivated tetravalent influenza vaccine has been available in Poland since the 2016/17 season, and also registered for children since the 2018/19 season. This is also in line with current Polish recommendations issued by the National Influenza Control Program. With the extremely low level of vaccination against influenza of the Polish population (about 3.7%), the threat of an influenza epidemic is serious. The number of reports describing simultaneously the immunological and clinical efficacy and tolerance of influenza vaccination of the Polish population is limited, the published works usually focus on the evaluation of either immunogenicity or clinical efficacy, there is a lack of publications comprehensively determining the effectiveness of the vaccine in the Polish homogeneous population, especially people in the above-mentioned risk groups, as well as the determination of the occurrence of the phenomenon of non-immunogenicity of the vaccine in the Polish population. An important aspect in the situation of low immunogenicity of the Polish population is the aspect of persistence of protective antibody levels at the beginning of the next flu season. Few works indicate the persistence of protective antibody levels in healthy individuals without risk factors for immune disorders, but the quality of "immune memory" after influenza vaccination in patients at risk of severe and complicated influenza is still insufficiently understood.

The aim of the study is to evaluate simultaneously the immunological and clinical efficacy and tolerability of an influenza vaccine, inactivated, quadrivalent, with cleaved virus, in patients at risk for severe and complicated influenza routinely vaccinated against influenza in family medicine clinics or specialty clinics (pediatric, internal medicine, cardiology, gynecological diabetes, pregnant women, transplant).

02

Conditions studied

  • Influenza
  • Obesity
  • Pregnancy; Infection
  • Elderly Infection
  • Vaccine Reaction
  • Vaccine Adverse Reaction
  • Tolerance

Keywords

  • influenza
  • vaccination
  • immunogenicity
  • efficacy
  • obesity
  • pregnancy
03

In context

Infections

6,687 studies on the registry are indexed under Infections; 807 are open to participants now.

This study's enrollment of 1,500 is above the median of 120 across 4,200 interventional studies indexed under Infections.

Browse Infections studies →

Lead sponsor

Medical University of Warsaw is the lead sponsor of 316 studies on the registry; 87 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 99 Years
Sexes eligible
All
Accepts healthy volunteers
Yes

Inclusion criteria

  1. age over 18 (adults able to give informed consent to participate in the study) or age under 18 and the consent of a legal guardian and, in the case of persons aged 16-18, also the consent of a minor;
  2. belonging to groups at risk of severe and complicated course of influenza (children, elderly people, patients with chronic diseases, pregnant women);
  3. no clinical contraindications to influenza vaccination;
  4. the patient and/or his legal guardians give written, informed consent to participate in the study.

Exclusion criteria

Exclusion criteria from the study:

  1. lack of consent to participate in the study - at every stage of the study;
  2. clinical contraindications to influenza vaccination.

Clinical contraindications to influenza vaccination:

  • exacerbation of a chronic disease;
  • acute infectious disease;
  • allergy to a vaccine component;
  • a serious allergic reaction after a previous flu vaccination;
  • Guillain-Barre syndrome up to 6 weeks after the previous vaccination;
  • use of immunosuppressive treatment (relative contraindication)
05

Study design

Phase
Phase 4
Primary purpose
Prevention
Allocation
Non-randomized
Intervention model
Parallel assignment
Masking
None (open label)
Enrollment
1,500 participants (actual)

Study arms

  • Experimental
    Evaluation of immunogenicity and tolerance of quadrivalent influenza vaccine in obese adults

    Scientific observations published during the 2009 influenza pandemic have highlighted the more severe course and complications of influenza in obese people. The effect of excessive body fat in humans on the immune response to influenza vaccination is not fully explained by the available studies. Study aim was the evaluation of immunological efficacy and tolerance of QIV in obese adult patients and the relationship between the degree of obesity and immunogenicity of quadrivalent QIV in obese adult patients. Free of charge influenza vaccination was done with a quadrivalent Sanofi Pasteur Vaxigrip Tetra vaccine at a dose of 0.5 ml according to WHO recommendations for 2017/2018 for the northern hemisphere.

    Drug: Vaxigrip

  • Experimental
    Immunogenicity of QIV in pregnant women, including transplacental transport of antibodies

    Many studies confirm the safety of vaccinations against influenza during pregnancy for pregnant women as well for children. Previous studies have assessed the immunological efficacy of a monovalent and trivalent vaccine, but studies assessing the immunological efficacy and tolerability of the tetravalent, inactivated influenza vaccine in pregnant women are missing.The aim of the study is to assess immunogenicity and tolerance of tetravalent, inactivated influenza vaccine in pregnant women, depending on the duration of vaccination (II or III trimester) by assessing the level of antibodies in neonatal umbilical cord blood (transplacental transfer). Free of charge influenza vaccination was done with a quadrivalent Sanofi Pasteur Vaxigrip Tetra vaccine at a dose of 0.5 ml according to WHO recommendations for 2021/2022, 2022/2023 for the northern hemisphere.

    Drug: Vaxigrip

Interventions

  • DrugVaxigrip

    Evaluation of immunogenicity and tolerance of quadrivalent influenza vaccine in groups at risk of severe influenza, including obese adults, as well as in pregnant women (with assesment of antibodies in cord blood).

06

What researchers measure

Primary outcomes

  1. influenza vaccine immunogenicity, seroconversion and seroprotection

    Immunogenicity is assessed using a hemagglutinin inhibition test. Percentage of patients with influenza antibody titers of 1:40 or more after vaccination. Seroconversion rate-a fourfold increase in the geometric mean titer after vaccination and the percentage of newborns with antibody titers of 1:40 or more at birth. Seroconversion and seroprotection were compared against the second and third trimesters of pregnancy. Transplacental transfer of antibodies was compared according to whether or not the patient had been vaccinated in previous seasons (applies only to the study on pregnant women.

    Time frame: 4-8 weeks after vaccination

Secondary outcomes

  1. assessment of vaccination tolerance

    Each patient will keep a diary of symptoms of adverse events occurring after vaccination and after 4 weeks will be asked to complete a survey (the survey was created in accordance with the Summary of Product Characteristics, CPMP and International Committee for Harmonization guidelines for the management of clinical safety data: definitions and standards for accelerated reporting).

    Time frame: 30 days after vaccination

07

Study locations

1 site
  • Department of Social Medicine and Public Health, Medical University of Warsaw
    Warsaw, 02-077, Poland
08

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Mar 1, 2024, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT06286488
Lead sponsor
Medical University of Warsaw
Responsible party
ANNA JAGIELSKA (Principal Investigator, Medical University of Warsaw) — Principal investigator
First posted
Feb 29, 2024
Start date
Sep 15, 2020
Primary completion
Aug 23, 2023
Completion
May 1, 2026 (estimated)
Last update
Mar 1, 2024

Study contacts

Monika Zasztowt-Sternicka, MD
principal investigator · Doctoral School, Medical University of Warsaw

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is active, not recruiting, as verified in Feb 2024. You cannot join it, but the record below documents what was studied.

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