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

Immunological and Clinical Effectiveness and Tolerability of Tetravalent Inactivated Influenza Vaccine in Patients at Risk for Severe and Complicated Influenza

Status
Active, not recruiting
Phases
Phase 4
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT06286488
Enrollment
1500
Registered
2024-02-29
Start date
2020-09-15
Completion date
2026-05-01
Last updated
2024-03-01

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

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

Keywords

influenza, vaccination, immunogenicity, efficacy, obesity, pregnancy

Brief 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).

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).

Interventions

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).

Sponsors

Medical University of Warsaw
Lead SponsorOTHER

Study design

Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
18 Years to 99 Years
Healthy volunteers
Yes

Inclusion criteria

for the study: 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

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)

Design outcomes

Primary

MeasureTime frameDescription
influenza vaccine immunogenicity, seroconversion and seroprotection4-8 weeks after vaccinationImmunogenicity 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.

Secondary

MeasureTime frameDescription
assessment of vaccination tolerance30 days after vaccinationEach 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).

Countries

Poland

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026