Infants aged 9 months will be randomized to receive a meningococcal vaccine at 9 months or 15 months. Infants randomized to the 9-month age group will be further randomized in a 2:1 ratio to receive a single dose of the experimental meningococcal vaccine (NmCV-5) or a single dose of the comparator meningococcal vaccine (MenACWY-TT). Prospectively identified and consented infants randomized to the 15-month age group will return when aged 15 months and will be randomized in a 2:1 ratio to receive a single dose of NmCV-5 or a single dose of MenACWY-TT.
Meningococcal meningitis, caused by invasive strains of Neisseria meningitidis, is a major public health concern because of its considerable morbidity and mortality in sub-Saharan Africa. Case fatality during meningococcal meningitis epidemics can surpass 15%, and rates of permanent sequelae among meningitis survivors in Africa are twice as high as they are in high income countries. Because of the fulminant clinical course of invasive bacterial meningitis and difficulties in access to care in the African meningitis belt, prevention by vaccination is the optimal way to reduce meningococcal meningitis morbidity and mortality. Before 2010, serogroup A meningococcal strains were routinely responsible for the majority (70-96%) of invasive meningococcal disease in sub-Saharan Africa. And annual epidemic could be associated with an incidence of meningococcal disease which could range between 100-1000 cases per 100,000 persons in any given year. Progressive introduction of MenAfriVac since 2010 has resulted in a substantial reduction in cases of serogroup A meningococcal disease. However, regular large-scale epidemics due to serogroups C, W and X remain common in the African meningitis belt. An affordable and scalable pentavalent meningococcal conjugate vaccine (NmCV-5) has been developed by Serum Institute of India Pvt. Ltd. (SIIPL), the manufacturer of MenAfriVac. NmCV-5 is designed to protect against serogroups A, C, W, Y and X. The immediate goal for the clinical development of NmCV-5 is for WHO Pre-Qualification (WHO-PQ), to enable the vaccine to be used in the Meningitis Belt of sub-Saharan Africa. This trial will evaluate a single dose of NmCV-5 administered at either 9 months or 15 months of age, time points in the Expanded Program on Immunization (EPI) schedule when meningococcal vaccine is most likely to be administered. Infants aged 9 months will be randomized to receive a meningococcal vaccine at 9 months or 15 months. Infants aged 9 months (eligibility 9-11 months) and randomized to the 9-month age group will be randomized in a 2:1 ratio to receive a single dose of NmCV-5 or a single dose of MenACWY-TT. Prospectively identified and consented infants randomized to the 15-month age group will return when aged 15 months (eligibility 15-17 months) and will be randomized in a 2:1 ratio to receive a single dose of NmCV-5 or a single dose of MenACWY-TT. "Enhanced" EPI vaccines will be co-administered and will consist of 2-doses of a measles-containing vaccine administered at 9 months and 15 months and a single dose of yellow fever vaccine administered at 9 months. This study protocol is designed to provide evidence that concomitant vaccination with NmCV-5 will not significantly affect the immune responses of infants to their normally scheduled EPI vaccines. This study has been specifically designed to provide information at two distinct timepoints, 9 months and 15 months. The current Mali EPI schedule consists of a measles only vaccine, yellow fever vaccine, and MenA vaccine at 9 months of age; there is no 15 months of age EPI vaccine visit and typically only a single dose of a measles-containing vaccine is administered. However, to satisfy the conditions for WHO-PQ, study participants will receive two doses of a measles-containing vaccine, at 9-months and 15-months. Furthermore, the noninferiority evaluation must include an assessment of the rubella vaccine responses. These modifications to the standard Malian EPI schedule provide a level-of-care that is higher than the current standard-of-care for the general population. Within the context of this study, the researchers will refer to this as an "enhanced" EPI schedule.
NmCV-5 is a pentavalent meningococcal (A, C, Y, W, X) polysaccharideconjugate vaccine composed of capsularpolysaccharides (PS) from Neisseria meningitidis serogroups A, C, Y, W, and X individually conjugated to a protein carrier, either mutant diphtheria toxoid (CRM197) or tetanus toxoid (TT).
MenACWY-TT (the comparator meningococcal vaccine) is a WHO-PQ quadrivalent meningococcal (A, C, Y, W) polysaccharide-conjugate vaccine manufactured by Pfizer.
Centre pour le Developpement des Vaccins du Mali
Bamako, Mali
Number of Participants With Seroprotection for Meningitis Serogroups A, C, W and Y
Null hypothesis: The immune response to meningitis serogroup "S" at Day 29 elicited by one dose of NmCV-5 is inferior to the immune response elicited by one dose of MenACWY-TT. Alternative hypothesis: The immune response to meningitis serogroup "S" at Day 29 elicited by one dose of NmCV-5 is non-inferior, by a pre-specified margin, to the immune response elicited by one dose of MenACWY-TT, where "S" denotes one of the meningitis serogroups: A, C, W or Y. Endpoints are the seroprotective response at Day 29 to serogroups A, C, W and Y in the NmCV-5 arm and seroprotective response at Day 29 to serogroups A, C, W and Y in the MenACWY-TT arm with seroprotective response defined as serogroup specific rSBA antibody titers ≥ 8. Non-inferiority comparisons are made between study vaccination arms within each study age group (9 months or 15 months of age). Proportions and difference in proportions are reported as percentages (number of infants per 100).
Time frame: Measured from time of meningococcal vaccination to blood sample collection at Day 29 visit. Follow-up time to Day 29 visit blood specimen collection was a mean (s.d.) of 30.9 (2.8) days.
Number of Participants With Seroprotection for Meningitis Serogroup X (NmCV-5) vs Lowest Comparator (MenACWY-TT)
Null hypothesis: At Day 29, the immune response to meningitis serogroup X elicited by one dose of NmCV-5 is inferior to the lowest immune response (among meningitis serogroups A, C, W or Y) elicited by one dose of MenACWY-TT. Alternative hypothesis: At Day 29, the immune response to meningitis serogroup X elicited by one dose of NmCV-5 is non-inferior, by a pre-specified margin, to the lowest immune response (among meningitis serogroups A, C, W or Y) elicited by one dose of MenACWY-TT. Endpoints are the seroprotective response to serogroup X in the NmCV-5 arm and the minimum seroprotective response among serogroups A, C, W and Y in the MenACWY-TT arm at Day 29 with seroprotective response defined as serogroup specific rSBA antibody titers ≥ 8. Non-inferiority comparisons are made between study vaccination arms within each study age group (9 months or 15 months). Proportions and difference in proportions are reported as percentages (number of infants per 100).
Time frame: Measured from time of meningococcal vaccination to blood sample collection at Day 29 visit. Follow-up time to Day 29 visit blood specimen collection was a mean (s.d.) of 30.9 (2.8) days.
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Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
TRIPLE
Enrollment
1,325
Number of Participants With Serious Adverse Events (SAE)
To assess the safety and tolerability of a single dose of NmCV-5 or MenACWY-TT, when given concomitantly with routine vaccines, all Serious Adverse Events (SAE) occurring during the first 6 months of the follow-up period after meningococcal vaccination are reported. Endpoints are the number of participants with unsolicited adverse events that are reported as Serious Adverse Events (SAEs) according to ICH/GCP guidelines or the study protocol collected from the time of Step 2 randomization and vaccination and with date of event onset up to and including Study Day 181.
Time frame: Measured from time of meningococcal vaccination to Study Day 181 or early study termination, whichever is earlier. Follow-up time to Study Day 181 visit was a mean (s.d.) of 180.8 (3.0) days.
Number of Participants With Solicited Adverse Events (Reactogenicity)
To assess the safety and tolerability of a single dose of NmCV-5 or MenACWY-TT, when given concomitantly with routine vaccines, all solicited AEs occurring during a 7-day follow-up period after meningococcal vaccination are reported. Solicited AEs include injection site (local) events (erythema/redness, induration/swelling, pain and/or tenderness) and systemic events (irritability, drowsiness/lethargy, decrease eating/anorexia, vomiting, fever (axillary), and feverish). Endpoints are the number of participants with solicited adverse events collected from about 30 minutes after meningococcal vaccination to Study Day 8 (7 days after vaccination). NOTE: Capture of data for symptom Feverish began on June 15, 2022, so some participants were not assessed for this symptom. Also, Fever (Axillary) is objectively measured by oral temperature and Feverish is a subjective observation from a parent who feels their infant has a raised temperature but not verified by thermometer.
Time frame: Measured from about 30 minutes after meningococcal vaccination to Study Day 8 (7 days) for all participants.
Number of Participants With Unsolicited Adverse Events
To assess the safety and tolerability of a single dose of NmCV-5 or MenACWY-TT, when given concomitantly with routine vaccines, all unsolicited AEs occurring through 28 days after meningococcal vaccination are reported. Unsolicited AEs include AEs reported in scheduled or interim (unscheduled) visits after receipt of meningitis vaccination and with date of onset up to and including Study Day 29. Endpoints are the number of participants reporting at least one unsolicited adverse event (overall and by MedDRA preferred term).
Time frame: Measured from time of meningococcal vaccination to Study Day 29 (28 days) for all participants.
Number of Participants With Seroprotection for Meningitis Serogroup X
Null hypothesis: The immune response to meningitis serogroup X at Day 29 elicited by one dose of NmCV-5 is not superior to the immune response elicited by one dose of MenACWY-TT, Alternative hypothesis: The immune response to meningitis serogroup X at Day 29 elicited by one dose of NmCV-5 is superior, by a pre-specified margin, to the immune response elicited by one dose of MenACWY-TT. Endpoints are the seroprotective response to serogroup X in the NmCV-5 arm at Day 29 and the seroprotective response defined to serogroup X in the MenACWY-TT arm at Day 29 with seroprotective response defined as serogroup specific rSBA antibody titers ≥ 8. Superiority comparisons are made between study vaccination arms within each study age group (9 months or 15 months of age). Proportions and difference in proportions are reported as percentages (number of infants per 100).
Time frame: Measured from time of meningococcal vaccination to blood sample collection at Day 29 visit. Follow-up time to Day 29 visit blood specimen collection was a mean (s.d.) of 30.9 (2.8) days.
Number of Participants With Seropositive Response to Measles Vaccine
Null hypothesis: The immune response to measles at Day 29 elicited by the MR vaccine when co-administered with one dose of NmCV-5 is inferior to the immune response elicited by the MR vaccine when co-administered with one dose of MenACWY-TT. Alternative hypothesis: The immune response to measles at Day 29 elicited by the MR vaccine when co-administered with one dose of NmCV-5 is non inferior, by a pre-specified margin, to the immune response elicited by the MR vaccine when co-administered with one dose of MenACWY-TT. Endpoints are the seropositive responses to measles vaccine at Day 29 post vaccination, defined as anti-measles IgG concentration \>200 mIU/mL. Non-inferiority comparisons are made between study vaccination arms within each study age group (9 months or 15 months of age). Proportions and difference in proportions are reported as percentages (number of infants per 100).
Time frame: Measured from time of meningococcal vaccination to blood sample collection at Day 29 visit. Follow-up time to Day 29 visit blood specimen collection was a mean (s.d.) of 30.9 (2.8) days.
Number of Participants With Seropositive Response to Rubella Vaccine
Null hypothesis: The immune response to rubella at Day 29 elicited by the MR vaccine when co-administered with one dose of NmCV-5 is inferior to the immune response elicited by the MR vaccine when co-administered with one dose of MenACWY-TT. Alternative hypothesis: The immune response to rubella at Day 29 elicited by the MR vaccine when co-administered with one dose of NmCV-5 is non inferior, by a pre-specified margin, to the immune response elicited by the MR vaccine when co-administered with one dose of MenACWY-TT. Endpoints are the seropositive responses to rubella vaccine at Day 29 post vaccination, defined as anti-rubella IgG concentration \>20 IU/mL. Non-inferiority comparisons are made between study vaccination arms within each study age group (9 months or 15 months of age). Proportions and difference in proportions are reported as percentages (number of infants per 100).
Time frame: Measured from time of meningococcal vaccination to blood sample collection at Day 29 visit. Follow-up time to Day 29 visit blood specimen collection was a mean (s.d.) of 30.9 (2.8) days.
Number of Participants With Seroprotective Response to Yellow Fever Vaccine
Null hypothesis: The immune response to yellow fever at Day 29 elicited by the yellow fever vaccine when co-administered with one dose of NmCV-5 is inferior to the immune response elicited by the yellow fever vaccine when co-administered with one dose of MenACWY-TT. Alternative hypothesis: The immune response to yellow fever at Day 29 elicited by the yellow fever vaccine when co-administered with one dose of NmCV-5 is non inferior, by a pre-specified margin, to the immune response elicited by the yellow fever vaccine when co-administered with one dose of MenACWY-TT. Endpoints are the seroprotective responses to yellow fever vaccine at Day 29 post vaccination, defined as yellow fever neutralizing antibody titers ≥10. Non-inferiority comparisons are made between study vaccination arms within the 9 months study age group only. Proportions and difference in proportions are reported as percentages (number of infants per 100).
Time frame: Measured from time of meningococcal vaccination to blood sample collection at Day 29 visit. Follow-up time to Day 29 visit blood specimen collection was a mean (s.d.) of 30.9 (2.8) days.
Geometric Mean of rSBA Titers for Meningitis Serogroups A, C, W, Y and X
For each study age group (9 months and 15 months) and for each of the five serogroups (A, C, W, Y, and X), geometric means and 95% CIs of rSBA titers at Day 29 are calculated by study vaccination arm within each study age group, and the Geometric Mean Titer (GMT) Ratio of rSBA titers at Day 29 for NmCV-5 relative to MenACWY-TT will be estimated, along with 95% CIs. The point and interval estimates will be obtained from a back transformation of the estimated difference in means of the log-transformed rSBA titers. Endpoints are the rSBA titer values for meningococcal serogroups A, C, W, Y and X, from samples collected at Visit 3 (Study Day 29).
Time frame: Measured from time of meningococcal vaccination to blood sample collection at Day 29 visit. Follow-up time to Day 29 visit blood specimen collection was a mean (s.d.) of 30.9 (2.8) days.
Seroresponse for Meningitis Serogroups A, C, W, Y and X
To assess clinically significant immune response indicators elicited by a single dose of meningococcal vaccine, the number and proportion of participants with seroresponse in rSBA titers at Day 29 is calculated for meningococcal serogroups A, C, W, Y and X. Endpoints are the number and percentage of participants with seroresponse in rSBA titers to meningococcal serogroups A, C, W, Y and X, from samples collected at Visit 3 (Study Day 29), where seroresponse is defined as a post-immunization (Day 29) rSBA titer of 32 or greater if the participant's pre-immunization (Baseline) rSBA titer was \< 8; or a ≥ four-fold increase over baseline at Day 29 post-immunization if the participant's pre-immunization rSBA titer was ≥ 8. Seroresponse is calculated for each study vaccination arm within each study age group (9 months or 15 months of age). Proportions are reported as percentages (number of infants per 100).
Time frame: Measured from time of blood sample collection just prior to meningococcal vaccination at Day 1 visit to blood sample collection at Day 29 visit. Follow-up time to Day 29 visit blood specimen collection was a mean (s.d.) of 30.9 (2.8) days.
Geometric Mean Fold Rise (GMFR) for Meningitis Serogroups A, C, W, Y and X
To assess clinically significant immune response indicators elicited by a single dose of meningococcal vaccine, the Geometric Mean Fold Rise (GMFR) from baseline to Day 29 of rSBA titers to meningococcal serogroups A, C, W, Y and X is estimated, with 95% CI. Endpoints are the rSBA titer values for meningococcal serogroups A, C, W, Y and X from samples collected at Visit 1 (Day 1) and Visit 3 (Day 29). The point and interval estimates will be obtained from a back transformation of the estimated mean difference of the log-transformed rSBA titers.
Time frame: Measured from time of blood sample collection just prior to meningococcal vaccination at Day 1 visit to blood sample collection at Day 29 visit. Follow-up time to Day 29 visit blood specimen collection was a mean (s.d.) of 30.9 (2.8) days.
Number of Participants With rSBA Titers ≥ 128 for Meningitis Serogroups A, C, W, Y and X
To assess clinically significant immune response indicators elicited by a single dose of meningococcal vaccine, the number and proportion of participants with rSBA titers ≥ 128 at Day 29 is calculated for meningococcal serogroups A, C, W, Y and X. Endpoints are the number and proportion of participants with rSBA titers ≥ 128 for meningococcal serogroups A, C, W, Y and X, from samples collected at Visit 3 (Study Day 29). This is calculated for each study vaccination arm within each study age group (9 months or 15 months of age). Proportions are reported as percentages (number of infants per 100).
Time frame: Measured from time of meningococcal vaccination to blood sample collection at Day 29 visit. Follow-up time to Day 29 visit blood specimen collection was a mean (s.d.) of 30.9 (2.8) days.