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An Effectiveness Trial to Evaluate Protection of Children and Pregnant Women by Influenza Vaccine in Rural Bangladesh

Phase 4
Active, not recruiting
Conditions
Influenza Viral Infections
Interventions
Biological: Inactivated polio vaccine
Biological: Inactivated influenza vaccine
Registration Number
NCT04998344
Lead Sponsor
University of Bergen
Brief Summary

Annually influenza is a leading cause of severe disease and mortality particularly in young children \<5 years old and pregnant women in the low and middle-income countries (LMICs) and both groups are prioritised for vaccination by the World Health Organisation (WHO). In Bangladesh, influenza is responsible for 10% of all childhood pneumonias and 9% of all death. Maternal influenza is associated with an increased risk of hospitalisation and foetal malformation. Influenza is a vaccine preventable disease, however, in most LMICs influenza vaccination is not part of the vaccination programme. This study will evaluate the effectiveness of inactivated influenza vaccine against influenza illness among pregnant women and children in Bangladesh. Influenza vaccine has not yet been studied as combined immunization strategy in a cluster randomized trial. This study is a community-based randomised trial in both pregnant women and young children to assess the impact of inactivated influenza vaccine in preventing influenza in the community as well as population level impact by both direct and indirect effect of vaccination.

Detailed Description

This clinical trial will be conducted in rural Matlab, Bangladesh, covered by a Maternal, Child Health and Family Planning intervention program (named MCH-FP area). Twenty villages in the Maternal, Child Health and Family Planning intervention program area will be randomized at a 1:1 ratio to receive either inactivated influenza vaccine (IIV) or the control inactivated polio vaccine (IPV). Recruitment, randomization and vaccination of healthy pregnant women at 28 to 34 weeks of gestation period and children 6 to 59 months old at the time of enrolment will be carried out from fixed site clinics working in the MCH-FP area. Vaccines will be administered as a single dose regimen for the pregnant women and two doses for children at 28-days interval as recommended by the vaccine manufacturers. All pregnant women in the third trimester of pregnancy (n\~300), and children 6 to 59 months old in 20 villages in the MCH-FP area of Matlab will be eligible for vaccination (n\~3500) for the study. In addition, all residents of study villages will be included in the influenza surveillance.

All vaccinated pregnant women and parents of vaccinated children 6 to 59 months old will be asked to inform the study team by phone of any respiratory illnesses or to visit the Matlab hospital. Also, all residents of the study villages will be asked to visit the Matlab hospital/fixed site clinic for any respiratory illness. Participants will receive regular SMS messages to remind them to report cases of influenza like illness (ILI). At the hospital, the medical officer will examine the sick patient and decide if the criteria of the ILI case definition are met. ILI is defined as an acute respiratory infection with: measured fever of ≥ 38 C° and cough; with onset within the last 10 days for adults; and in case of children as measured axillary temperature ≥ 38.0°C with onset within the last 10 days and at least one of the following symptoms: cough, sore throat, nasal congestion, rhinorrhea, earache or ear discharge. In medically confirmed ILI cases, the trial will collect nasopharyngeal and throat swabs for confirmation of the aetiology of the infection, as well as collect serum samples from vaccinated participants Passive surveillance will continue for 18 months following completion of vaccination.

Outcome measures/variables:

1. Incidence, prevalence, seasonality and clinical descriptions of :

1. Influenza infection including clinical pneumonia in child (fever, cough and respiratory difficulties)

2. Influenza infection including clinical pneumonia in mother (fever, cough and respiratory difficulties)

2. HAI antibody titres to calculate the rate of reduction of risk of influenza infection or disease in influenza vaccination pregnant women and children as well as reduction of flu infection in population of intervention and control villages

3. Evaluation of simple sample collection methods in children to assess Influenza specific antibody responses in DBS and saliva sample

4. Clinical and demographic risk factors associated with illness

5. Comparisons of pregnancy outcomes and post-delivery illness/complication

6. Clinical and laboratory confirmation of influenza and other respiratory virus in sick individuals

7. Economic evaluation of influenza vaccination in pregnant women and children

Recruitment & Eligibility

Status
ACTIVE_NOT_RECRUITING
Sex
All
Target Recruitment
3800
Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Inactivated polio vaccine groupInactivated polio vaccineVaccines will be administered as a single dose regimen for the pregnant women and two doses for children at 28-day interval as recommended by the vaccine manufacturers.
Inactivated influenza vaccine groupInactivated influenza vaccineVaccines will be administered as a single dose regimen for the pregnant women and two doses for children at 28-day interval as recommended by the vaccine manufacturers.
Primary Outcome Measures
NameTimeMethod
Effectiveness of influenza vaccination in reducing rates of acute respiratory infections due to laboratory-confirmed influenza in pregnant women at 28 to 34 weeks of gestation period and children 6 to 59 months oldthrough study completion, an average of 3 year

The direct effectiveness of influenza vaccine in reducing rates of acute influenza infections in vaccinated patients attending a treatment facility will be assessed. The indirect effectiveness will be calculated by comparing the rates of influenza in the villages where influenza vaccine is introduced to the influenza rates in people from villages vaccinated with the control vaccine.

Secondary Outcome Measures
NameTimeMethod
Safety of influenza vaccine among pregnant women at 28 to 34 weeks of gestation period and children 6 to 59 months old in Bangladeshthrough study completion, an average of 1.5 year

The safety of the vaccine will be monitored through a field visit on Day 3 after each dose of vaccination and thereafter by telephone. All adverse events will be recorded, and any serious adverse events will be investigated. Adverse events after vaccination will be summarized and compared between the intervention and control groups.

Surveillance for influenza and other respiratory virusesthrough study completion, an average of 3 year

In medically confirmed ILI cases, nasopharyngeal and throat swabs will be collected for laboratory confirmation of the aetiology of the infection, Passive surveillance will continue for 18 months following completion of vaccination.

Vaccine immunogenicity in pregnant women and childrenthrough study completion, an average of 3 year

The hemagglutination inhibition assay will be used to assess the vaccine immunogenicity to the homologous vaccine strains and appropriate epidemic strains.

Indirect vaccine effectiveness of influenza vaccination of pregnant women and childrenthrough study completion, an average of 3 year

All residents of the 20 study villages will be included in the influenza surveillance. Influenza cases will be defined as laboratory confirmed rRT-PCR influenza A and/or B viruses during the influenza surveillance period. The total and indirect vaccine protection in the population will be assessed from medical records for birth outcomes, birth weights, ILI, hospitalization and death records in Matlab.

Trial Locations

Locations (2)

Norwegian University of Science and Technology

🇳🇴

Trondheim, Norway

International Centre for Diarrhoeal Disease Research, Bangladesh

🇧🇩

Dhaka, Bangladesh

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