Earlier Prime-BOOST Schedule to Improve MEasles Protection in High Burden Settings

Phase 2RecruitingNCT06667206

University of Oxford450 enrolled

Overview

This is a phase IIb clinical trial investigating the non-inferiority of immune responses in children given two doses of measles vaccine at different timepoints. The study will randomise 450 children to 3 groups: group A will receive measles containing vaccine (MCV) at 6 and 12 months ; group B at 9 and 18 months; Group C at 6 and 18 months.

Two doses of measles containing vaccine (MCV) are recommended in young children with the first dose given at different times depending on the setting. In low-incidence settings the MCV1 is given at 12 months of age or later as more infants over 12 months of age respond to MCV1 due to the absence of maternal antibody interference and an overall better immune response due to the maturation of the infant immune system. In high measles incidence settings MCV1 is given earlier at 9 months of age as there is no remaining protection from maternal antibody at this age and risk of infection if unvaccinated can be high. However, in children born with low levels or rapid decay of maternal antibody, the 9-month timing for MCV1 means the infant may be susceptible to infection for some months prior to vaccination. Therefore, in settings of high infant measles incidence, an early first dose at 6 months of age may bridge this susceptibility gap. Our study will assess differences in protective levels of measles antibody in children randomised to receive early (6 months) or standard (9 months) MCV1 in a high incidence measles setting, and early (12 months) or standard (18 months) booster vaccines, in those who are given early MCV1. There will be 5 blood draws over 2 years. The study will compare children who received a) two doses of measles vaccine at 6 and 18 months with 9 and 18 months, and b) two doses of measles vaccine at 6 and 12 months compared with 6 and 18 months. The study is funded by the Bill \& Melinda Gates Foundation (INV-048650)

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

NONE

Enrollment

450

Conditions

Measles

Interventions

Licenced Measles-Rubella vaccineBIOLOGICAL

Licenced Measles-Rubella vaccine provided by the Ugandan EPI programme

Eligibility

Sex: ALLMin age: 23 WeeksMax age: 28 WeeksHealthy volunteers:

Medical Language ↔ Plain English

1. Trial Participants Children aged 6 months (23 - 28 weeks) at time of screening 2. Inclusion Criteria * Aged 6 months (23 - 28 weeks) at time of screening * Received all previous vaccines as per country Expanded Programme of Immunization (EPI) schedule, verified by child health card * Parents/caretakers willing to give informed consent for their and their children's participation and stay in the geographical area where the study would be conducted 3. Exclusion Criteria The participant may not enter the trial if any of the following apply: * Child not healthy enough to be vaccinated in the opinion of the investigator * Recent family history of measles infection (since birth) * Previous receipt of any measles vaccination * A family history of congenital or hereditary immunodeficiency other than HIV * Receipt of more than 1 week of immunosuppressant or immune modifying drugs e.g. high dose steroids. * Major congenital defects or serious chronic illness that in the opinion of the investigator are likely to modify immune responses or the ability to comply with the requirements of the study. * History of any neurological disorders or seizures * Administration of immunoglobulins and/or any blood products since birth or planned administration during the study period * Other abnormalities or medical history that contraindicated measles vaccination

Locations (1)

Makarere University - Johns Hopkins University Collaboration

Kampala, Uganda

RECRUITING

Outcomes

Primary Outcomes

Protective measles antibody concentrations at 2.5 years of age

Proportion of participants with protective levels of measles neutralising antibodies (PRNT\>120mIUL)

Time frame: 2.5 years of age

Local and systemic reactions

Reactogenicity profile from diary cards

Time frame: 7 days post each vaccination

Serious Adverse Events

Time frame: 2 years: (from baseline vaccination until 2 year follow up visit)

Secondary Outcomes

Measles plaque reduction neutralisation titre (PRNT) and immunoglobulin G (IgG) concentration

Measles PRNT and IgG concentrations one month after first dose in infants receiving an early (6 months) compared to standard (9 month) dose of MCV

Time frame: one month after first dose

The effect of maternal human immunodeficiency virus (HIV) infection

Infant PRNT and IgG responses post MCV1 and MCV2 in children of mothers with and without HIV

Time frame: one month after first dose and second dose

The effect of maternal antibodies on infant immune response

Relationship between baseline titres (pre vaccination) and 4 week post-vaccination titres for PRNT, Measles IgG, and measles ELISpot.

Time frame: pre-vaccination, 4 weeks after the first dose, 4 weeks after the second dose

Immune response to rubella component of the vaccine

Anti-rubella IgG

Time frame: 4 weeks after a first and second dose

Central Contacts

Oxford Vaccine Group

CONTACT

01865 611400 info@ovg.ox.ac.uk

Data from ClinicalTrials.gov

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