Ignite Creation Date:
2024-05-05 @ 11:45 AM
Last Modification Date:
2024-10-26 @ 9:12 AM
Study NCT ID:
NCT00121823
Status:
COMPLETED
Last Update Posted:
2017-01-12
First Post:
2005-07-18
Brief Title:
Malaria Infection Diagnosed by Polymerase Chain Reaction PCR as a Means of Evaluating Pre-erythrocytic Candidate Malaria Vaccines
Sponsor:
London School of Hygiene and Tropical Medicine
Organization:
London School of Hygiene and Tropical Medicine
Study Overview
Official Title:
Malaria Infection Diagnosed by PCR as a Means of Evaluating Pre-erythrocytic Candidate Malaria Vaccines
Status:
COMPLETED
Status Verified Date:
2017-01
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
None
Brief Summary:
The ability to test candidate pre-erythrocytic stage malaria vaccines using a well-established sporozoite challenge model in a field setting with group sizes of tens rather than hundreds of volunteers would greatly facilitate identification of the most promising vaccine candidates The investigators assessed the suitability and acceptability of this method in a field trial in semi-immune volunteers exposed to natural infection during the high malaria transmission season
Detailed Description:
Objective
The primary objective of the study was to determine if the very sensitive PCR technique capable of detecting malaria parasites at low densities could be used as an economical method of undertaking preliminary field evaluation of pre-erythrocytic malaria vaccines A secondary objective was to determine if the intensive blood sampling that this method requires would be acceptable
Study area
This study was conducted from June to October 2004 when the incidence of malaria in The Gambia is highest Volunteers were recruited from 9 villages east of Farafenni a town which is 200km east of the capital city Banjul Malaria is highly seasonal in this area with an entomological inoculation rate between 10 and 50 infectious bites per year
Study population
Healthy volunteers aged between 15-45 years were screened at two centres for their eligibility to take part in the study Screening involved a thorough physical examination as well as blood sampling tests for haematological full blood count packed cell volume PCV renal plasma creatinine level and hepatic alanine amino transferase tests and for HIV 1 and 2 tests by ELISA A glucose-6-phosphate dehydrogenase G6PD deficiency test was carried out because of the risk involved with administering the study drugs Primaquine and Lapdap to volunteers who are G6PD deficient Exclusion criteria included a PCV 30 raised plasma creatinine 130 micromoleslitre or ALT levels 42 IUlitre G6PD deficiency simultaneous participation in another clinical trial blood transfusion in the month prior to vaccination previous experimental malaria vaccination administration of another vaccine within 2 weeks of vaccination allergy to any previous vaccination or to sulphadoxinepyrimethamine history of splenectomy and any treatment with immunosuppressive drugs
Study procedure
Eligible volunteers were enrolled into the study after written informed consent was obtained All eligible volunteers were issued a unique number and a photo identification card Volunteers were randomly allocated into three groups to receive either two 5 x107 pfu doses of FP9 ME-TRAP followed by a single dose of 1 x 108 pfu MVA ME-TRAP malaria vaccine group or 3 doses of rabies vaccine Fansidar and rabies groups All vaccines were give 4 weeks apart and were administered intradermally Following vaccination all volunteers were observed for 1 hr and given a course of anti-pyretic paracetamol to take if required In addition home visits were made by field workers on days 1 2 7 and 28 after each vaccination to record adverse events using a standard diary card All volunteers received a single dose of Primaquine 30mg 7 days before the final dose of vaccination as radical cure for gametocytes and a 3-day course of the short acting anti-malaria drugs Lapdap and Artesunate in combination starting on the day of final vaccination to clear any asexual forms of the parasite before the follow-up period Additionally volunteers in the Fansidar group received the long acting anti-malarial drug and were expected to remain PCR negative throughout the follow-up period Volunteers were followed up intensively for 28 days starting 7days after the last vaccination The period of follow-up was timed to correspond with the period of high malaria transmission Follow-up was by daily finger-pricks to obtain 05mls of blood in a microtainer for PCR analysis and a duplicate blood film for estimation of malaria parasites Laboratory staff that conducted immunoassays and PCR analysis were blind to the group allocation of volunteers until after approval of the analysis plan by the Data Safety Monitoring Board DSMB
Sample size
Based on practical and statistical considerations the researchers proposed to enroll 40 volunteers per group a total of 120 Allowing for a steady rate of drop-out during follow up amounting to total of 20 of subjects by the end of the trial the trial has at least 80 power to detect a difference in time to infection between the malaria vaccine and rabies groups if the vaccine efficacy is at least 60 and at least 70 of the control group volunteers develop detected parasitaemia during the trial
Data Safety Monitoring Board DSMB
A DSMB was set up to oversee the conduct of the trial and approve the analytical plan before unblinding the laboratory staff The trial was conducted according to ICH Good Clinical Practice guidelines and was guided by the Medical Research Council regulations for the conduct of clinical trials
The primary objective of the study was to determine if the very sensitive PCR technique capable of detecting malaria parasites at low densities could be used as an economical method of undertaking preliminary field evaluation of pre-erythrocytic malaria vaccines A secondary objective was to determine if the intensive blood sampling that this method requires would be acceptable
Study area
This study was conducted from June to October 2004 when the incidence of malaria in The Gambia is highest Volunteers were recruited from 9 villages east of Farafenni a town which is 200km east of the capital city Banjul Malaria is highly seasonal in this area with an entomological inoculation rate between 10 and 50 infectious bites per year
Study population
Healthy volunteers aged between 15-45 years were screened at two centres for their eligibility to take part in the study Screening involved a thorough physical examination as well as blood sampling tests for haematological full blood count packed cell volume PCV renal plasma creatinine level and hepatic alanine amino transferase tests and for HIV 1 and 2 tests by ELISA A glucose-6-phosphate dehydrogenase G6PD deficiency test was carried out because of the risk involved with administering the study drugs Primaquine and Lapdap to volunteers who are G6PD deficient Exclusion criteria included a PCV 30 raised plasma creatinine 130 micromoleslitre or ALT levels 42 IUlitre G6PD deficiency simultaneous participation in another clinical trial blood transfusion in the month prior to vaccination previous experimental malaria vaccination administration of another vaccine within 2 weeks of vaccination allergy to any previous vaccination or to sulphadoxinepyrimethamine history of splenectomy and any treatment with immunosuppressive drugs
Study procedure
Eligible volunteers were enrolled into the study after written informed consent was obtained All eligible volunteers were issued a unique number and a photo identification card Volunteers were randomly allocated into three groups to receive either two 5 x107 pfu doses of FP9 ME-TRAP followed by a single dose of 1 x 108 pfu MVA ME-TRAP malaria vaccine group or 3 doses of rabies vaccine Fansidar and rabies groups All vaccines were give 4 weeks apart and were administered intradermally Following vaccination all volunteers were observed for 1 hr and given a course of anti-pyretic paracetamol to take if required In addition home visits were made by field workers on days 1 2 7 and 28 after each vaccination to record adverse events using a standard diary card All volunteers received a single dose of Primaquine 30mg 7 days before the final dose of vaccination as radical cure for gametocytes and a 3-day course of the short acting anti-malaria drugs Lapdap and Artesunate in combination starting on the day of final vaccination to clear any asexual forms of the parasite before the follow-up period Additionally volunteers in the Fansidar group received the long acting anti-malarial drug and were expected to remain PCR negative throughout the follow-up period Volunteers were followed up intensively for 28 days starting 7days after the last vaccination The period of follow-up was timed to correspond with the period of high malaria transmission Follow-up was by daily finger-pricks to obtain 05mls of blood in a microtainer for PCR analysis and a duplicate blood film for estimation of malaria parasites Laboratory staff that conducted immunoassays and PCR analysis were blind to the group allocation of volunteers until after approval of the analysis plan by the Data Safety Monitoring Board DSMB
Sample size
Based on practical and statistical considerations the researchers proposed to enroll 40 volunteers per group a total of 120 Allowing for a steady rate of drop-out during follow up amounting to total of 20 of subjects by the end of the trial the trial has at least 80 power to detect a difference in time to infection between the malaria vaccine and rabies groups if the vaccine efficacy is at least 60 and at least 70 of the control group volunteers develop detected parasitaemia during the trial
Data Safety Monitoring Board DSMB
A DSMB was set up to oversee the conduct of the trial and approve the analytical plan before unblinding the laboratory staff The trial was conducted according to ICH Good Clinical Practice guidelines and was guided by the Medical Research Council regulations for the conduct of clinical trials
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
None
Is a FDA Regulated Device?:
None
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None
Secondary IDs
| Secondary ID | Type | Domain | Link |
|---|---|---|---|
| VAC 029 | None | None | None |