Clinical Trial: Evaluation of PCV Schedules in a Naive Population in Vietnam

Study Status: Not yet recruiting
Recruit Status: Not yet recruiting
Study Type: Interventional

Official Title: Evaluation of PCV Schedules in a Naive Population in Vietnam

Brief Summary: The cost of pneumococcal conjugate vaccine use can be greatly reduced by making use of existing herd immunity to protect children against vaccine type pneumococci. The investigators will reduce the circulation of vaccine type pneumococci to low levels by PCV catch-up campaign; vaccinating all children less than 3 years of age with PCV, after which the investigators will evaluate the ability of a simplified two doses regimen and an alternative one dose regimen to prevent the reintroduction of vaccine type pneumococci compared to the WHO recommended 2 doses schedule.

Detailed Summary:

Background Pneumococcal conjugate vaccine (PCVs) have substantially reduced the burden of pneumococcal disease. WHO currently recommends giving PCVs as 3 doses - either 3 doses in infancy with Pentavalent vaccine (3p+0), or two doses in infancy followed by a booster around the end of the first year of life (2p+1). The 3p+0 schedule is used in many countries introducing PCV with Gavi support while several European countries are using 2p+1 schedule. However, their high price and the current recommendation for at least 3 doses to achieve full individual protection for infants, introduces a substantial financial burden. As a result, many middle income countries have not yet introduced PCVs, and low income countries that have introduced PCVs with the aid of the Gavi, the Vaccine Alliance, may not be able to sustain PCV vaccination after graduating from GAVI support.

To date PCV programs have been designed to provide optimal individual protection of the vaccinees, yet experience in developed countries indicates that herd immunity, which is generated by reducing carriage and hence transmission of vaccine serotypes in the community, controls vaccine type pneumococcal disease in vaccinated and unvaccinated individuals alike [1]. Using PCV impact on vaccine type carriage as a marker of vaccine type disease [2], the investigators will investigate the feasibility of reducing the number of infant doses in the PCV immunization schedule, to make more efficient use of herd immunity in the protection against pneumococcal disease.

Study aim and objectives Primary objective 1- The investigators will measure the effect of the 1p+1 schedule on vaccine type pneumococcal carriage and non-inferiority compared to a 2p+1 or 3p+0 schedule in (a) children aged 4-11 months, i.e. after the age of a completed primary series and before the age where they
Sponsor: Nagasaki University

Current Primary Outcome: vaccine type pneumococcal carriage [ Time Frame: up to 48 months after PCV intervention ]

Original Primary Outcome: Same as current

Current Secondary Outcome:

Original Secondary Outcome:

Information By: Nagasaki University

Dates:
Date Received: November 1, 2016
Date Started: November 2016
Date Completion: December 2020
Last Updated: November 8, 2016
Last Verified: November 2016