Evaluating the Effectiveness of a Pneumococcal Immunisation Campaign in a Camp for Internally Displaced People

Pneumococcal conjugate vaccine (PCV) is used routinely worldwide as part of infant immunisations to prevent acquisition of Streptococcus pneumoniae, the aetiologic agent responsible for a large proportion of early childhood pneumonia and invasive disease. However, PCV has seen minimal uptake in populations affected by forced displacement and humanitarian crises, where the burden of pneumococcal disease is plausibly elevated.

This study seeks to generate evidence on appropriate vaccination strategies for crisis-affected populations. The investigators plan to exhaustively vaccinate children up to 15 years in a camp for displaced persons outside Hargeisa, the capital of Somaliland. The study will deliver PCV in a campaign modality, so as to achieve both short- and long-term herd immunity effects that, the investigators hypothesise, will reduce population-wide nasopharyngeal S. pneumoniae transmission and thereby protect young children from pneumococcal disease.

The study will adopt a quasi-experimental design, with baseline and post-intervention surveys to evaluate changes in pneumococcal carriage, complemented by safety assessment in children aged over 2 years, for whom PCV safety data are scarce, and longitudinal data collection on incidence of pneumonia and antibiotic prescriptions in the camp.


Eligibility Criteria:
Inclusion Criteria:

* Resident in Digaale camp
* Voluntary written/thumb-printed informed consent has been provided by a parent or caretaker;
* Subject's parent must be able to comprehend and comply with study requirements and procedures;
* Subject's parents must have a readily identifiable place of residence in the study area, be available for the duration of study participation, and have a means of telephone contact

Exclusion Criteria:

* Known hypersensitivity to any component of the vaccine, including diphtheria toxoid;
* History of allergic disease or history of a serious reaction to any prior vaccination or known hypersensitivity to any component of the study vaccines. This includes such reactions in older siblings and also includes all components of the Expanded Programme of Immunization vaccines;
* History of anaphylactic shock;
* Any abnormal (Grade ≥ 1) vital sign. Note: An abnormal vital sign, including fever (axillary temperature of ≥ 37.5°C), may be repeated to determine whether a subject is eligible for vaccination. A minimum of 48 hours following a documented fever must pass before the subject can be reassessed for eligibility.
* Any moderate or severe (Grade ≥ 2) acute illness. Note: Infants with a Grade 1 acute illness may be enrolled at the discretion of the PI. Note: Subjects with moderate or severe acute illness may return for clinical re-assessment; if the illness has sufficiently resolved, they may still qualify for vaccination.
* Chronic administration (defined as more than 14 consecutive days) of immunosuppressant or other immune modifying drugs prior to the administration of the study vaccine, including the use of glucocorticoids. The use of topical and inhaled glucocorticoids is not an exclusion criterion.