The effect of intensive treatment for schistosomiasis on response to vaccines among island adolescents in Uganda

ISRCTN ISRCTN60517191
DOI https://doi.org/10.1186/ISRCTN60517191
Secondary identifying numbers v1
Submission date
12/03/2019
Registration date
01/05/2019
Last edited
21/10/2024
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Infections and Infestations
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data

Plain English Summary

Background and study aims
Infectious diseases remain very common in low-income countries (LICs). Vaccines protect people against infectious diseases, but several important vaccines do not work as well in LICs compared to high-income countries (HICs) and in rural, compared to urban, settings. One possible reason for this might be that people living in these settings are more likely to have worm infections. Worm infections impact on the immune system and may change an infected person’s response to a vaccine. This study aims to investigate whether treating adolescents infected with schistosomiasis, a parasitic worm infection, before vaccination, will lead to a better immune response to these vaccines.

Who can participate?
Healthy volunteer children (aged 9-17, with no gender restriction) from selected schools located in the Koome islands of Lake Victoria, Uganda. Schistosomiasis is very common in this area.

What does the study involve?
Children are randomly allocated to receive either intensive or standard praziquantel treatment for schistosomiasis. Intensive praziquantel treatment is three doses, 2 weeks apart, of praziquantel before vaccination followed by quarterly praziquantel for a period of one year. Standard praziquantel treatment is once a year. They are then vaccinated against tuberculosis, yellow fever, human papilloma virus (which can cause cancer of the cervix [or opening] of the womb, and other cancers), typhoid and tetanus. Four weeks after vaccination, their immune responses to each vaccine are measured.

What are the possible benefits and risks of participating?
Participants will benefit from receiving the vaccines and treatments as they are expected to provide protection against infectious diseases. Participants and their families, schools and communities will benefit from improved understanding of schistosomiasis and vaccines. No major risks to the participants are anticipated since all the treatments and vaccines to be given are licensed and known to be safe. The main risk to participants will be time lost from school work, and the researchers will work with teachers and parents to minimise this. Very rarely, a vaccine may cause a severe allergic reaction, so individuals who have previously suffered a possible allergic reaction to drugs or vaccines or their components will not be included in the study.

Where is the study run from?
The host institution for the study will be the Medical Research Council/Uganda Virus Research Institute and London School of Hygiene and Tropical Medicine Uganda Research Unit (MRC/UVRI & LSHTM), Entebbe, Uganda.

When is the study starting and how long is it expected to run for?
May 2018 to August 2020

Who is funding the study?
Medical Research Council (UK)

Who is the main contact?
Prof. Alison Elliott
alison.elliott@lshtm.ac.uk

Contact information

Dr Emily Webb
Public

LSHTM
Keppel St
London
WC1E 7HT
United Kingdom

Phone +44 (0)207 9272012
Email emily.webb@lshtm.ac.uk
Prof Alison Elliott
Scientific

MRC/UVRI and LSHTM Uganda Research Unit
Entebbe
UVRI P.O.Box 49
Uganda

Phone +44 (0)207 6368636
Email alison.elliott@mrcuganda.org

Study information

Study designSingle-centre open individually randomised two parallel group trial
Primary study designInterventional
Secondary study designRandomised parallel trial
Study setting(s)School
Study typeOther
Participant information sheet ISRCTN60517191_PIS_05Sept2020.pdf
Scientific titlePopulation differences in vaccine response: the role, reversibility and mediators of immunomodulation by chronic infections in the tropics (POPVAC). Trial Protocol A: the effect of intensive treatment for schistosomiasis on response to vaccines among island adolescents in Uganda
Study acronymPOPVAC trial A
Study hypothesisSchistosoma mansoni infection suppresses responses to unrelated vaccines, and this effect can be reversed, at least in part, by intensive praziquantel treatment intervention.
Ethics approval(s)1. Approved 05/09/2018, MRC/UVRI and LSHTM Uganda Research Unit Research Ethics Committee (Plot 51-59, Nakiwogo Road, Entebbe, P.O. Box 49, Entebbe-Uganda; +256 414 320 385/6; directoruvri@uvri.go.ug), ref: GC/127/18/09/680
2. Approved 07/05/2019, Uganda National Council for Science and Technology (Plot 6, Kimera Road, Ntinda, P.O. Box 6884, Kampala-Uganda; +256 414 705500; infor@uncst.go.ug), ref: HS 2486
3. Approved 28/05/2019, National Drug Authority (Plot 19 Lumumba Avenue, P.O. Box 23096, Kampala, Uganda; +256 417 788 100; ndaug@nda.or.ug), ref: 351/NDA/DPS/05/2019
4. Approved 05/06/2019, London School of Hygiene and Tropical Medicine Interventional Ethics Committee (Keppel Street, London WC1E 7HT; +44(0)20 7636 8636; ethics@lshtm.ac.uk), ref: 16032
ConditionVaccine responses
InterventionA randomisation code will be generated by the trial statistician using a randomly permuted block size. Participants will be allocated in a 1:1 ratio to receive either intensive or standard praziquantel treatment. Participants in the intensive arm will receive three doses of praziquantel (PZQ) (40mg/kg, assessed by height pole) each two weeks apart (the last of these 2-4 weeks before immunisation), followed by quarterly PZQ (approximately; timings adjusted to accommodate school terms) during follow up. Participants in the standard arm will receive annual PZQ (Uganda Ministry of Health (MoH) policy) given after immunisation and after primary endpoint sampling.
Intervention typeDrug
Pharmaceutical study type(s)
PhaseNot Applicable
Drug / device / biological / vaccine name(s)Praziquantel
Primary outcome measure1. BCG: BCG-specific IFN-gamma ELIspot response 8 weeks post BCG immunisation
2. YF-17D: neutralising antibody titres (plaque-reduction neutralisation test) at 4 weeks post YF immunisation
3. Ty21a: Salmonella typhi lipopolysaccharide (LPS)-specific immunoglobulin(Ig)G concentration at 4 weeks post Ty21a immunisation
4. HPV: IgG specific for L1-proteins of HPV-16/18 at 4 weeks post HPV priming immunisation
5. Td: tetanus and diphtheria toxoid-specific IgG concentration at 4 weeks post Td immunisation
Secondary outcome measuresCurrent secondary outcome measures as of 24/07/2019:
1. Protective immunity. Proportions with protective neutralising antibody (YF); protective IgG levels (TT); seroconversion rates (Ty21a) at 4 weeks post the corresponding immunisation
2. Response waning. Primary outcome measures (all vaccines) repeated at week 52, and area-under-the curve (AUC) analyses
3. Priming versus boosting. Effects on priming versus boosting will be examined for HPV only, comparing outcomes 4 weeks after the first, and 4 weeks after the second vaccine dose
4. Current S. mansoni infection status and intensity. This will be determined by serum/plasma levels of circulating anodic antigen (CAA). The method is quantitative, highly specific for Schistosoma infection, and much more sensitive than the conventional Kato Katz method. CAA will be assessed retrospectively on stored samples collected at baseline, on immunisation days, and on primary and secondary endpoint days.

Previous secondary outcome measures:
1. Protective immunity. Proportions with protective neutralising antibody (YF); protective IgG levels (TT); seroconversion rates (Ty21a) at 4 weeks post the corresponding immunisation
2. Response waning. Primary outcome measures (all vaccines) repeated at week 52, and area-under-the curve (AUC) analyses
3. Priming versus boosting. Effects on priming versus boosting will be examined for HPV only, comparing outcomes 4 weeks after the first, and 4 weeks after the second vaccine dose
Overall study start date01/05/2018
Overall study end date30/11/2020

Eligibility

Participant type(s)Healthy volunteer
Age groupChild
Lower age limit9 Years
Upper age limit17 Years
SexBoth
Target number of participants480
Total final enrolment479
Participant inclusion criteria1. Attending the selected school and planning to continue to attend the school for the duration of the study
2. Aged 9 to 17 year and enrolled in primary 4, 5 or 6
3. Written informed consent by parent or guardian
4. Written informed assent by participant
5. Agree to avoid pregnancy for the duration of the trial (female only)
6. Willing to provide locator information and to be contacted during the course of the trial
7. Able and willing (in the investigator's opinion) to comply with all the study requirements
Participant exclusion criteria1. Clinically significant history of immunodeficiency (including HIV), cancer, cardiovascular disease, gastrointestinal disease, liver disease, renal disease, endocrine disorder and neurological illness
2. History of serious psychiatric condition or disorder
3. Concurrent oral or systemic steroid medication or the concurrent use of other
immunosuppressive agents within 2 months prior to enrolment
4. History of allergic reaction to immunisation or any allergy likely to be exacerbated by any component of the study vaccines including egg or chicken proteins
5. History of previous immunisation with YF, oral typhoid or HPV vaccine; previous immunisation with BCG or Td at age >5 years
6. Tendency to develop keloid scars
7. Haemoglobin less than 82g/L
8. Positive HIV serology
9. Positive pregnancy test
10. Female currently lactating, confirmed pregnancy or intention to become pregnant during the trial period
11. Use of an investigational medicinal product or non-registered drug, live vaccine, or medical device other than the study vaccines for 30 days prior to dosing with the study vaccine, or planned use during the study period
12. Administration of immunoglobulins and/or any blood products within the three months preceding the planned trial immunisation date
Recruitment start date08/07/2019
Recruitment end date23/08/2019

Locations

Countries of recruitment

  • Uganda

Study participating centre

MRC/UVRI and LSHTM Uganda Research Unit
Plot 51-59 Nakiwogo Road
Entebbe
-
Uganda

Sponsor information

London School of Hygiene and Tropical Medicine
University/education

Keppel Street
London
WC1E 7HT
England
United Kingdom

Phone +44 (0)207 636 8636
Email postmaster@lshtm.ac.uk
Website http://www.lshtm.ac.uk
ROR logo "ROR" https://ror.org/00a0jsq62

Funders

Funder type

Research council

Medical Research Council
Government organisation / National government
Alternative name(s)
Medical Research Council (United Kingdom), UK Medical Research Council, MRC
Location
United Kingdom

Results and Publications

Intention to publish date01/07/2024
Individual participant data (IPD) Intention to shareNo
IPD sharing plan summaryStored in repository
Publication and dissemination planCurrent publication and dissemination plan as of 05/05/2022:
The trial protocol has been published. The main trial results will be submitted for publication in early 2023.


Previous publication and dissemination plan as of 10/06/2020:
The researchers plan to publish the study protocol on around 01/12/2019. They will also add the statistical analysis plan to the trial registration before database lock. They then plan to publish the results of the trial in a high-impact peer-reviewed journal with an intention to publish date of 31/08/2021.

Previous publication and dissemination plan:
The researchers plan to publish the study protocol on around 01/12/2019. They will also add the statistical analysis plan to the trial registration before database lock. They then plan to publish the results of the trial in a high-impact peer-reviewed journal with an intention to publish date of 31/08/2021.
IPD sharing planThe de-identified individual participant data that underlie the results reported in journal articles will be stored in a non-publically available repository (LSHTM Data Compass), together with a data dictionary. This will be done at the time of publication. Each dataset will be allocated a unique digital object identifier (DOI). Researchers who would like to access the data may submit a request through LSHTM Data Compass, detailing the data requested, the intended use for the data, and evidence of relevant experience and other information to support the request. The request will be reviewed by the Principal Investigator in consultation with the POPVAC Steering Committee, with oversight from the UVRI and LSHTM ethics committees. In line with the MRC policy on Data Sharing, there will have to be a good reason for turning down a request. Patient Information Sheets and consent forms specifically referenced making anonymised data available and this has been approved by the relevant ethics committees. Researchers given access to the data will sign data sharing agreements which will restrict the use to answering pre-specified research questions.

Study outputs

Output type Details Date created Date added Peer reviewed? Patient-facing?
Statistical Analysis Plan 01/11/2019 19/03/2020 No No
Statistical Analysis Plan version v2.0 01/12/2020 27/01/2021 No No
Protocol article 16/02/2021 05/05/2022 Yes No
Protocol article scientific rationale and cross-cutting analyses 16/02/2021 26/10/2022 Yes No
Participant information sheet Information sheet for participants 9 to 12 years old 05/09/2020 09/07/2024 No Yes
Results article 01/11/2024 21/10/2024 Yes No

Additional files

ISRCTN60517191_SAP_01Nov19.doc
Uploaded 19/03/2020
ISRCTN60517191_SAP_v2.0_01Dec2020.doc
uploaded 27/01/2021
ISRCTN60517191_PIS_05Sept2020.pdf
Information sheet for participants 9 to 12 years old

Editorial Notes

21/10/2024: Publication reference added.
09/07/2024: Participant information sheet added.
05/06/2024: The intention to publish date was changed from 31/12/2023 to 01/07/2024.
10/03/2023: The intention to publish date was changed from 31/03/2023 to 31/12/2023.
26/10/2022: Publication reference added.
05/05/2022: The following changes have been made:
1. Publication reference added.
2. The publication and dissemination plan has been updated.
3. The intention to publish date has been changed from 30/11/2021 to 31/03/2023.
27/01/2021: The statistical analysis plan version 2 was uploaded as an additional file.
11/09/2020: Internal review.
05/08/2020: The following changes have been made:
1. The overall trial end date has been changed from 31/08/2020 to 30/11/2020.
2. The intention to publish date has been changed from 31/08/2021 to 30/11/2021.
3. The final enrolment number has been added.
10/06/2020: The following changes were made to the trial record:
1. The publication and dissemination plan was updated and the IPD sharing statement was added.
2. The participant-level data was changed from "To be made available at a later date" to "Stored in repository".
19/03/2020: Uploaded statistical analysis plan.
14/08/2019: The following changes were made to the trial record:
1. The recruitment start date was changed from 17/06/2019 to 08/07/2019.
2. The recruitment end date was changed from 19/07/2019 to 23/08/2019.
3. The overall trial end date was changed from 30/04/2022 to 31/08/2020.
4. The intention to publish date was changed from 30/04/2023 to 31/8/2021.
24/07/2019: The following changes were made to the trial record:
1. The ethics approval was added.
2. The secondary outcome measures were changed.
27/03/2019: Trial's existence confirmed by MRC/UVRI REC.