Impact of a Fourth Hexavalent Vaccine After Hematopoietic Stem Cell Transplantation

Study Overview
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Brief Summary
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It is recommended for patients who underwent an hematopoietic stem cell transplantation to receive 6 months after the graft 3 injections of hexavalent vaccine (diphteria-tetanus- poliomyelitis-pertussis-Hib-HBV) within 2 months followed by a booster dose one month after. The patients included in the study will have a measure of their antibody level against 5 pathogens (diphteria toxin, tetanus toxin, Haemophilus influenza b, hepatitis B virus, poliomyelitis virus) one month after the 3rd injection of hexavalent vaccine. If the antibody response is not sufficient, they will be randomized for a 4th dose in the following month. The antibody response will be again measured one month after the 1 year booster dose.

Detailed Description
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It is recommended for patients who underwent an hematopoietic stem cell transplantation to receive, 6 months after the graft, 3 injections of hexavalent vaccine (diphteria-tetanus- poliomyelitis-pertussis-Hib-HBV) within 2 months, followed by a booster dose one yrar after. However, this strategy do not constantly lead to efficient antibody levels. the investigators aim to determine whether a 4th dose in the initial vaccine schedule (month 0, 1, 2, and 3) allows to obtain a better response. After informed consent, the investigators will recruit 6 months after the graft 200 patients who had received an hematopoietic stem cell transplantation . The participants will have a measure of their antibody level against 5 pathogens (diphteria toxin, tetanus toxin, Haemophilus influenza b, hepatitis B virus, poliomyelitis virus) at month 0 (before the 1st hexavalent vaccine injection), and one month after the 3rd injection of this vaccine. If the antibody response is not sufficient, they will be randomized for a 4th dose in the following month. The one year booster dose will be then injected to all participants, and the antibody response will be again measured one month after this dose. The primary endpoint is to compare the antibody levels at this date in patients who had an unsufficient immune response after the 3rd dose and who received or not a 4rth dose in the initial vaccine schedule.

Official Title
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Impact of a Fourth Hexavalent Vaccine Dose During Primary Vaccination After Haematopoietic Stem Cell Transplantation

Conditions
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Haemopoietic Stem Cell Transplantation, Allograft

Intervention / Treatment
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* Drug: 4th dose of hexavalent vaccine 1 month after the 3rd dose


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: having received an HSTC 6 months before (not more than 2 years) not receiving immunosuppressive therapy at inclusion Exclusion Criteria: having received an HSTC 6 months more than 2 years before receiving immunosuppressive therapy at inclusion

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: randomized, open-label, prospective, multicenter study
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: good resp. after 3 vacc. inject.<br>no randomization for a 4th dose. | |
| Experimental: bad resp. after 3 vacc. inj., 4th inj<br>After randomization, these patients will receive a 4th dose one month after the 3rd dose. | Drug: 4th dose of hexavalent vaccine 1 month after the 3rd dose<br>* 4th dose of hexavalent vaccine 1 month after the 3rd dose<br>|
| No Intervention: bad resp. after 3 vacc. inj., no 4th inj<br>After randomization, these patients will not receive a 4th dose one month after the 3rd dose. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| antibody response 1 month after the one year booster dose | antibody level against 5 pathogens (diphteria toxin, tetanus toxin, Haemophilus influenza b, hepatitis B virus, poliomyelitis virus) one month after the 3rd injection of hexavalent vaccine | 1 month after the one year booster dose | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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haemopoietic stem cell transplantation, vaccine, diphteria, tetanus, haemophilus influenza, poliomyelitis, hepatitis B