Condition category
Infections and Infestations
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Not provided at time of registration

Trial website

Contact information



Primary contact

Dr Marie-Pierre Preziosi


Contact details

World Health Organization
20 Avenue Appia
+41 (0)22 791 3744



Additional contact

Prof Samba Sow


Contact details

Centre pour les Vaccins en Développement (CVD)
BP 251



Additional contact

Dr Brown Okoko


Contact details

PO Box 273

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

A phase II, observer-blind, randomised, active controlled study to compare the safety, immunogenicity, and induction of immunological memory of a meningococcal A conjugate vaccine, a meningococcal ACYW polysaccharide vaccine and a hib conjugate vaccine, administered in healthy toddlers 12 - 23 months of age


Study hypothesis

The present study is pivotal, designed as a non-inferiority trial to evaluate the immunogenicity and the safety of one dose of 10 µg of PsA-TT vaccine. Immunological memory and persistence of antibodies induced by a single intramuscular injection of the study vaccine will also be evaluated. The immunogenicity will be assessed against that of a licensed meningococcal polysaccharide ACYW vaccine. The three-group design will allow comparison of the PsA-TT vaccine (study vaccine group) safety profile with that of two licensed vaccines: the meningococcal ACYW tetravalent polysaccharide vaccine (Mencevax - reference vaccine group), and the Hib-conjugate vaccine (Hiberix - control vaccine group). The booster study is expected to provide evidence that the PsA-TT conjugate vaccine is able to prime immunological memory. Antibody persistence will be evaluated at eight months (i.e. before the booster dose), one year and two years after the first dose.

Ethics approval

This protocol has been approved by the following institutions:
1. Human Subjects Protection Committee at PATH, USA
2. University of Maryland Baltimore Institutional Review Board (IRB), USA
3. Comité d'Ethique de la Faculté de Médecine, de Pharmacie et d'Odonto-Stomatologie, Mali
4. Medical Research Council Scientific Coordinating Committee, The Gambia
5. Medical Research Council Gambia Government Ethics Committee, The Gambia
6. World Health Organization (WHO) Research Ethics Review Committee

Study design

Phase II observer-blind randomised active-controlled study

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use contact details to request a participant information sheet


Meningococcal A disease


The intervention is vaccination at day zero of one of the three vaccines: study vaccine, reference vaccine (Mencevax) or control vaccine (Hiberix) , followed by a booster vaccination 32 weeks later with one of the three vaccines, study vaccine, reference vaccine (1/5th of a dose) or control vaccine. Subjects will be randomised in a 1:1:1 ratio.

Intervention type



Drug names

Primary outcome measures

The percentage of subjects who show a seroconversion for anti-Meningococcal Polysaccharide A (MenPsA) antibodies, i.e. a four-fold increase in post-immunisation serum titre with respect to pre-immunisation serum titre, at 28 days after a single vaccine dose, as measured by rank Signaling Block Age (rSBA) assay.

Secondary outcome measures

1. The percentage of subjects with local and systemic adverse events, including solicited adverse reactions and events, and Serious Adverse Events (SAEs), as measured at four and 28 days after the primary vaccination (reactogenicity and short-term safety)
2. The percentage of subjects with local and systemic adverse events, including solicited adverse reactions and events, and SAEs, as measured at four and 28 days after the booster vaccination (reactogenicity and short-term safety)
3. The percentage of subjects who show a seroconversion for anti-MenPsA total Immunoglobulin G (IgG), i.e. a two-fold increase in post-immunisation serum concentration with respect to pre-immunisation serum concentration, at 28 days after a single vaccine dose, as measured by the Enzyme-Linked ImmunoadSorbent Assay (ELISA). The percentage of subjects with a four-fold increase in post-immunisation serum concentration with respect to pre-immunisation serum concentration will be also considered

Overall trial start date


Overall trial end date


Reason abandoned


Participant inclusion criteria

1. Age 12 to 23 months of age (both included)
2. Written informed consent obtained from the mother, father, or guardian of the child
3. Free of obvious health problems as established by medical history including physical examination and clinical judgment of the investigator
4. Mother, father, or guardian capable and willing to bring their child or to receive home visits for their child for all follow-up visits
5. Residence in the study area
6. Fully vaccinated according to local Expanded Program on Immunisation (EPI) schedule

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. Previous vaccination against serogroup A Neisseria meningitidis
2. Known exposure to serogroup A Neisseria meningitidis during the three previous months
3. History of allergic disease or known hypersensitivity to any component of the three study vaccines
4. History of Serious Adverse Reactions (SAR) following administration of vaccines included in the local program of immunization
5. Administration of any other vaccine within 60 days prior to administration of study vaccines or planned vaccination during the first four weeks after the study vaccination
6. Use of any investigational or non-registered drug within 90 days prior to the administration of study vaccines
7. Administration of immunoglobulins and/or any blood products since birth or planned administration during the vaccine period
8. Chronic administration (defined as more than 14 days) of immunosuppressants or other immune-modifying agents since birth (including systemic or inhaled corticosteroids, this means prednisone or equivalent, 0.5 mg/kg/day [topical steroids are allowed])
9. A family history of congenital or hereditary immunodeficiency
10. History of meningitis or seizures or any neurological disorder
11. Major congenital defects or serious chronic illness, including malnutrition (as per investigator's judgment)
12. Acute disease at the time of enrolment (acute disease is defined as the presence of a moderate or severe illness with or without fever) is a temporary exclusion
13. Acute or chronic, clinically significant pulmonary, cardiovascular, hepatic, or renal functional abnormality, as determined by medical history, physical examination or laboratory tests, which in the opinion of the investigator, might interfere with the study objectives
14. Any condition or criteria that in the opinion of the investigator might compromise the well being of the subject or the compliance with study procedures or interfere with the outcome of the study
15. Non-residence in the study area or intent to move out within one year

Recruitment start date


Recruitment end date



Countries of recruitment

Gambia, Mali

Trial participating centre

World Health Organization

Sponsor information


Serum Institute of India Limited (SIIL)

Sponsor details


Sponsor type

Research organisation



Program for Appropriate Technology in Health (PATH)

Sponsor details

1455 NW Leary Way
WA 98107
United States of America

Sponsor type

Research organisation



Funder type


Funder name

Bill and Melinda Gates Foundation

Alternative name(s)

Bill & Melinda Gates Foundation

Funding Body Type

private sector organisation

Funding Body Subtype



United States of America

Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Results - basic reporting

Publication summary

2011 results in:
2015 results in:
2015 results in:
2015 results in:
2015 results in:
2015 results in:
2015 results in:

Publication citations

  1. Results

    Sow SO, Okoko BJ, Diallo A, Viviani S, Borrow R, Carlone G, Tapia M, Akinsola AK, Arduin P, Findlow H, Elie C, Haidara FC, Adegbola RA, Diop D, Parulekar V, Chaumont J, Martellet L, Diallo F, Idoko OT, Tang Y, Plikaytis BD, Kulkarni PS, Marchetti E, LaForce FM, Preziosi MP, Immunogenicity and safety of a meningococcal A conjugate vaccine in Africans., N. Engl. J. Med., 2011, 364, 24, 2293-2304, doi: 10.1056/NEJMoa1003812.

  2. Results

    Borrow R, Tang Y, Yakubu A, Kulkarni PS, LaForce FM, MenAfriVac as an Antitetanus Vaccine, Clin Infect Dis, 2015 , 61 , Suppl 5, S570-S577, doi: 10.1093/cid/civ512.

  3. Results

    Holme D, Findlow H, Sow SO, Idoko OT, Preziosi MP, Carlone G, Plikaytis BD, Borrow R, Neisseria meningitidis Group A IgG1 and IgG2 Subclass Immune Response in African Children Aged 12-23 Months Following Meningococcal Vaccination, Clin Infect Dis, 2015 , 61, Suppl 5, S563-S569, doi: 10.1093/cid/civ505.

  4. Results

    Tang Y, Plikaytis BD, Preziosi MP, Borrow R, Influence of Age on Antibody Response and Persistence Following Immunization With MenAfriVac, Clin Infect Dis, 2015 , 61, Suppl 5, S531-S539, doi: 10.1093/cid/civ601.

  5. Results

    Tapia MD, Findlow H, Idoko OT, Preziosi MP, Kulkarni PS, Enwere GC, Elie C, Parulekar V, Sow SO, Haidara FC, Diallo F, Doumbia M, Akinsola AK, Adegbola RA, Kampmann B, Chaumont J, Martellet L, Marchetti E, Viviani S, Tang Y, Plikaytis BD, LaForce FM, Carlone G, Borrow R, Antibody Persistence 1-5 Years Following Vaccination With MenAfriVac in African Children Vaccinated at 12-23 Months of Age, Clin Infect Dis, 2015 , 61 , Suppl 5, S514-S520, doi: 10.1093/cid/civ672.

  6. Results

    Martellet L, Sow SO, Diallo A, Hodgson A, Kampmann B, Hirve S, Tapia M, Haidara FC, Ndiaye A, Diarra B, Ansah PO, Akinsola A, Idoko OT, Adegbola RA, Bavdekar A, Juvekar S, Viviani S, Enwere GC, Marchetti E, Chaumont J, Makadi MF, Pallardy F, Kulkarni PS, Preziosi MP, LaForce FM, Ethical Challenges and Lessons Learned During the Clinical Development of a Group A Meningococcal Conjugate Vaccine, Clin Infect Dis, 2015 , 61 , Suppl 5, S422-S427, doi: 10.1093/cid/civ598.

  7. Results

    Idoko OT, Diallo A, Sow SO, Hodgson A, Akinsola A, Diarra B, Haidara FC, Ansah PO, Kampmann B, Bouma E, Preziosi MP, Enwere GC, Community Perspectives Associated With the African PsA-TT (MenAfriVac) Vaccine Trials, Clin Infect Dis, 2015 , 61 , Suppl 5, S416-S421, doi: 10.1093/cid/civ596.

Additional files

Editorial Notes

31/08/2016: Publication references added. This trial was accepted and approved by the ISRCTN on the 18/09/2006, but assigned an ISRCTN on the 21/09/2006 due to technical reasons. The date of the ISRCTN assignment should be taken as the 18/09/2006.