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

Evaluating the Effectiveness of a Pneumococcal Immunisation Campaign in a Camp for Internally Displaced People: A Non-randomised, Quasi-experimental Phase IV Intervention Study

Pneumococcal conjugate vaccine (PCV) is used routinely worldwide as part of infant immunisations to prevent acquisition of S. 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 aged between six months and four 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, who fall outside of the WHO prequalification age range for the vaccine that will be used in this study (i.e. PNEUMOSIL) and for whom PCV safety data are scarce. In addition, we the study will also collect longitudinal data on incidence of pneumonia and antibiotic prescriptions in the camp.

Study Overview

• Status: Active, not recruiting
• Conditions: Pneumococcal Infections
• Intervention / Treatment: Biological: Pneumococcal conjugate vaccine

• Study Type: Interventional
• Enrollment (Actual): 2882
• Phase: Phase 4

Contacts and Locations

Study Locations

• Somalia
  • Hargeisa, Somaliland
    • Hargeisa, Hargeisa, Somaliland, Somalia
      • Digaale internally displaced persons camp

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 1 month to 14 years (Child)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Resident in Digaale camp
2. Voluntary written/thumb-printed informed consent has been provided by a parent or caregiver
3. Subject's parent/caregiver must be able to comprehend and comply with study requirements and procedures
4. Subject's parents/caregivers must have a readily identifiable place of residence in the study area

Exclusion Criteria:

1. Known hypersensitivity to any component of any of the EPI vaccines, including diphtheria toxoid, in the child or any sibling
2. History of allergic disease or history of a serious reaction to any prior vaccination in the child or any sibling
3. History of anaphylactic shock, regardless of cause
4. History of long-term treatment (defined as 14 or more consecutive days) with immunosuppressants or other immune modifying drugs, including glucocorticoids, but excluding topical and inhaled glucocorticoids

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Mass vaccination; Mass vaccination of children aged 6 weeks to 4 years old with pneumococcal conjugate vaccine (PNEUMOSIL). Children 6 weeks to 11 months old receive two doses, spaced 4 weeks apart. All other children receive a single dose. Vaccination is simultaneous, as per a campaign delivery strategy.	Biological: Pneumococcal conjugate vaccine; Mass campaign offering simultaneous pneumococcal conjugate vaccination to all children aged below 5 years of age living in Digaale camp, Somaliland. Children aged below 12 months receive 2 doses of vaccine, spaced 4 weeks apart. All other children receive one dose.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Nasopharyngeal carriage of one or more colonies of vaccine-type Streptococcus pneumoniae serotypes in children below 24 months old	The outcome is determined at the individual level, through polymerase chain reaction (PCR) microarray analysis of nasal swab samples collected during a cross-sectional, population-representative sample survey of camp residents. The analysis will be stratified by age group (0-11 months, 12-23 months). Vaccine-type serotypes are defined as those that the Pneumosil vaccine (Serum Institute, India) is designed to provide immunity for, and include serotypes serotypes 1, 5, 6A, 6B, 7F, 9V, 14, 19A, 19F and 23F.	6 months, relative to baseline (pre-vaccination)
Nasopharyngeal carriage of one or more colonies of vaccine-type Streptococcus pneumoniae serotypes in children below 24 months old	The outcome is determined at the individual level, through PCR microarray analysis of nasal swab samples collected during a cross-sectional, population-representative sample survey of camp residents. The analysis will be stratified by age group (0-11 months, 12-23 months). Vaccine-type serotypes are defined as those that the Pneumosil vaccine (Serum Institute, India) is designed to provide immunity for, and include serotypes serotypes 1, 5, 6A, 6B, 7F, 9V, 14, 19A, 19F and 23F.	12 months, relative to baseline (pre-vaccination)
Nasopharyngeal carriage of one or more colonies of vaccine-type Streptococcus pneumoniae serotypes in children below 24 months old	The outcome is determined at the individual level, through PCR microarray analysis of nasal swab samples collected during a cross-sectional, population-representative sample survey of camp residents. The analysis will be stratified by age group (0-11 months, 12-23 months). Vaccine-type serotypes are defined as those that the Pneumosil vaccine (Serum Institute, India) is designed to provide immunity for, and include serotypes serotypes 1, 5, 6A, 6B, 7F, 9V, 14, 19A, 19F and 23F.	24 months, relative to baseline (pre-vaccination)
Number and proportion of vaccination recipients who experience solicited or unsolicited severe adverse events (SAE) following vaccination	The outcome is determined at the individual level. SAE are defined as any AEFI with severity >= 3. Outcome ascertainment will occur through (i) in-person monitoring of vaccine recipients for 30 min after vaccine administration, (ii) exhaustive follow-up of all vaccine recipients 7 days after vaccination, with administration of a structured questionnaire to their parents or caregivers; (iii) availability of a 24/7 phone number which caregivers of vaccine recipients will be encouraged to contact; (iv) visits to the camp's single primary healthcare facility, during each day on which vaccination takes place, to identify any children presenting for care with a SAE; and (v) availability of a 24/7 phone number which clinicians at the primary healthcare facility will be encouraged to contact. Each SAE will be followed up until resolution. Relatedness of each SAE to vaccine receipt will be classified as 'unrelated', 'unlikely', 'possible', 'probable', 'definite' and 'not assessable'.	within 7 days of receipt of each vaccine dose
Number and proportion of vaccination recipients who experience solicited local and systemic adverse events following immunisation (AEFI)	The outcome is determined at the individual level. 'Solicited' indicates that adverse events are identified by study staff using a pre-defined checklist of signs and symptoms and proactive monitoring or follow-up of vaccine recipients. AEFI will be coded using the Medical Dictionary for Regulatory Activities (MedDRA) (version 24.0 or later). Outcome ascertainment will occur through (i) in-person monitoring of vaccine recipients for 30 minutes after vaccine administration, and (ii) exhaustive follow-up of all vaccine recipients 7 days after vaccination, with administration of a structured questionnaire to their parents or caregivers. All AEFI will be graded using a severity scale (0 - none; 1 - mild; 2 - moderate; 3- severe; 4 - very severe; 5 - fatal), and analysis will be stratified by severity and age group (6 weeks to 11 months old, 12 to 23 months old, 24 to 59 months old).	within 7 days of receipt of each vaccine dose

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Nasopharyngeal carriage of one or more colonies of vaccine-type Streptococcus pneumoniae serotypes in children and adults 24 months old or older	The outcome is determined at the individual level, through PCR microarray analysis of nasal swab samples collected during a cross-sectional, population-representative sample survey of camp residents. The analysis will be stratified by age group (24-59 months, 5 to 14 years, 15 to 29 years, 30 to 49 years, 50 years and above). Vaccine-type serotypes are defined as those that the Pneumosil vaccine (Serum Institute, India) is designed to provide immunity for, and include serotypes serotypes 1, 5, 6A, 6B, 7F, 9V, 14, 19A, 19F and 23F.	6 months, relative to baseline (pre-vaccination)
Nasopharyngeal carriage of one or more colonies of vaccine-type Streptococcus pneumoniae serotypes in children and adults 24 months old or older	The outcome is determined at the individual level, through PCR microarray analysis of nasal swab samples collected during a cross-sectional, population-representative sample survey of camp residents. The analysis will be stratified by age group (24-59 months, 5 to 14 years, 15 to 29 years, 30 to 49 years, 50 years and above). Vaccine-type serotypes are defined as those that the Pneumosil vaccine (Serum Institute, India) is designed to provide immunity for, and include serotypes serotypes 1, 5, 6A, 6B, 7F, 9V, 14, 19A, 19F and 23F.	12 months, relative to baseline (pre-vaccination)
Nasopharyngeal carriage of one or more colonies of vaccine-type Streptococcus pneumoniae serotypes in children and adults 24 months old or older	The outcome is determined at the individual level, through PCR microarray analysis of nasal swab samples collected during a cross-sectional, population-representative sample survey of camp residents. The analysis will be stratified by age group (24-59 months, 5 to 14 years, 15 to 29 years, 30 to 49 years, 50 years and above). Vaccine-type serotypes are defined as those that the Pneumosil vaccine (Serum Institute, India) is designed to provide immunity for, and include serotypes serotypes 1, 5, 6A, 6B, 7F, 9V, 14, 19A, 19F and 23F.	24 months, relative to baseline (pre-vaccination)
Nasopharyngeal carriage of one or more colonies of non-vaccine-type Streptococcus pneumoniae serotypes in children and adults	The outcome is determined at the individual level, through PCR microarray analysis of nasal swab samples collected during a cross-sectional, population-representative sample survey of camp residents. The analysis will be stratified by age group (0-11 months, 12-23 months, 24-59 months, 5 to 14 years, 15 to 29 years, 30 to 49 years, 50 years and above). Non-vaccine-type serotypes are defined as those that the Pneumosil vaccine (Serum Institute, India) is not designed to provide immunity for, i.e. any serotypes other than 1, 5, 6A, 6B, 7F, 9V, 14, 19A, 19F or 23F.	6 months, relative to baseline (pre-vaccination)
Nasopharyngeal carriage of one or more colonies of non-vaccine-type Streptococcus pneumoniae serotypes in children and adults	The outcome is determined at the individual level, through PCR microarray analysis of nasal swab samples collected during a cross-sectional, population-representative sample survey of camp residents. The analysis will be stratified by age group (0-11 months, 12-23 months, 24-59 months, 5 to 14 years, 15 to 29 years, 30 to 49 years, 50 years and above). Non-vaccine-type serotypes are defined as those that the Pneumosil vaccine (Serum Institute, India) is not designed to provide immunity for, i.e. any serotypes other than 1, 5, 6A, 6B, 7F, 9V, 14, 19A, 19F or 23F.	12 months, relative to baseline (pre-vaccination)
Nasopharyngeal carriage of one or more colonies of non-vaccine-type Streptococcus pneumoniae serotypes in children and adults	The outcome is determined at the individual level, through PCR microarray analysis of nasal swab samples collected during a cross-sectional, population-representative sample survey of camp residents. The analysis will be stratified by age group (0-11 months, 12-23 months, 24-59 months, 5 to 14 years, 15 to 29 years, 30 to 49 years, 50 years and above). Non-vaccine-type serotypes are defined as those that the Pneumosil vaccine (Serum Institute, India) is not designed to provide immunity for, i.e. any serotypes other than 1, 5, 6A, 6B, 7F, 9V, 14, 19A, 19F or 23F.	24 months, relative to baseline (pre-vaccination)
Mean bacteriological density of vaccine- and non-vaccine-type Streptococcus pneumoniae infections, among children and adults with at least one infecting colony in the nasopharynx	The outcome is determined at the individual level, through PCR microarray analysis of nasal swab samples collected during a cross-sectional, population-representative sample survey of camp residents. Bacteriological density is estimated after PCR analysis as copies per milliliter. The analysis will be stratified by age group (0-11 months, 12-23 months, 24-59 months, 5 to 14 years, 15 to 29 years, 30 to 49 years, 50 years and above), and by vaccine-type versus non-vaccine-type serotype colonies. Vaccine-type serotypes are defined as those that the Pneumosil vaccine (Serum Institute, India) is designed to provide immunity for, i.e. 1, 5, 6A, 6B, 7F, 9V, 14, 19A, 19F or 23F. Non-vaccine serotypes are defined as any other serotype.	6 months, relative to baseline (pre-vaccination)
Mean bacteriological density of vaccine- and non-vaccine-type Streptococcus pneumoniae infections, among children and adults with at least one infecting colony in the nasopharynx	The outcome is determined at the individual level, through PCR microarray analysis of nasal swab samples collected during a cross-sectional, population-representative sample survey of camp residents. Bacteriological density is estimated after PCR analysis as copies per milliliter. The analysis will be stratified by age group (0-11 months, 12-23 months, 24-59 months, 5 to 14 years, 15 to 29 years, 30 to 49 years, 50 years and above), and by vaccine-type versus non-vaccine-type serotype colonies. Vaccine-type serotypes are defined as those that the Pneumosil vaccine (Serum Institute, India) is designed to provide immunity for, i.e. 1, 5, 6A, 6B, 7F, 9V, 14, 19A, 19F or 23F. Non-vaccine serotypes are defined as any other serotype.	12 months, relative to baseline (pre-vaccination)
Mean bacteriological density of vaccine- and non-vaccine-type Streptococcus pneumoniae infections, among children and adults with at least one infecting colony in the nasopharynx	The outcome is determined at the individual level, through PCR microarray analysis of nasal swab samples collected during a cross-sectional, population-representative sample survey of camp residents. Bacteriological density is estimated after PCR analysis as copies per milliliter. The analysis will be stratified by age group (0-11 months, 12-23 months, 24-59 months, 5 to 14 years, 15 to 29 years, 30 to 49 years, 50 years and above), and by vaccine-type versus non-vaccine-type serotype colonies. Vaccine-type serotypes are defined as those that the Pneumosil vaccine (Serum Institute, India) is designed to provide immunity for, i.e. 1, 5, 6A, 6B, 7F, 9V, 14, 19A, 19F or 23F. Non-vaccine serotypes are defined as any other serotype.	24 months, relative to baseline (pre-vaccination)
Incidence rate of hospitalisations due to acute lower respiratory infection (ALRI) among children aged below 2 years of age	The outcome is determined at the population level, as a rate per person-time after division by the camp's estimated population of children aged below 2 years of age, updated through exhaustive census every 6 months. Hospitalisation is defined as admission of a child residing in the camp to a paediatric inpatient facility, with a final diagnosis of acute lower respiratory infection or pneumonia. The outcome is ascertained through a manual search of registers of all paediatric facilities that the camp population can realistically utilise, complemented by perusal of outpatient register records of the camp's single primary healthcare facility, to identify instances of children referred to hospitals. The diagnosis is as per clinical records. The outcome is ascertained retrospectively at baseline (vaccination campaign), and once every 6 months post-vaccination, for 24 months. However, only results after 24 months are analysed.	24 months, relative to baseline (pre-vaccination)
Rate of antibiotic prescription at outpatient care among children aged below 5 years of age	The outcome is determined at the aggregate (population) level, as a rate per person-time after division by the camp's estimated population of children aged below 5 years of age, which will also be updated through an exhaustive census every 6 months. The outcome is ascertained through consultation of the pharmacy register of the camp's single primary healthcare facility, by tallying the number of single prescriptions issued by the pharmacy to outpatients. Antibiotics are defined as per the World Health Organization's Model List of Essential Medicines. The outcome is ascertained retrospectively through record review conducted at baseline (vaccination campaign), and once every 6 months post-vaccination, for 24 months. However, only results after 24 months are analysed.	24 months, relative to baseline (pre-vaccination)
Proportion of the target population who receive the specified dosing regimen of pneumococcal conjugate vaccine during the vaccination campaign	The outcome is determined at the individual level, but will be analysed at an aggregate (population) level, with stratification by age group (6 weeks to 11 months old, 12 to 23 months old, 24 to 59 months old, 5 to 14 years old). Before the vaccination campaign, all children aged 6 weeks old to 14 years old living in the camp will be systematically identified and registered. This list will serve as the denominator for the outcome, while the numerator will be children on the list who are successfully vaccinated, as per campaign administrative records. Successful vaccination is defined as injection with two doses of Pneumosil vaccine, spaced 4 weeks apart, in children aged 6 weeks to 11 months old, and one dose of Pneumosil vaccine in children aged 1 to 14 years old.	Single time point - baseline (vaccination campaign)

Collaborators and Investigators

• Sponsor: London School of Hygiene and Tropical Medicine
• Collaborators: Save the Children; Murdoch Childrens Research Institute; Ministry of Health Development, Somaliland

Publications and helpful links

General Publications

• van Zandvoort K, Hassan AI, Bobe MO, Pell CL, Ahmed MS, Ortika BD, Ibrahim S, Abdi MI, Karim MA, Eggo RM, Ali SY, Hinds J, Soleman SM, Cummings R, McGowan CR, Mulholland EK, Hergeye MA, Satzke C, Checchi F, Flasche S. Pre-vaccination carriage prevalence of Streptococcus pneumoniae serotypes among internally displaced people in Somaliland: a cross-sectional study. Pneumonia (Nathan). 2024 Dec 5;16(1):25. doi: 10.1186/s41479-024-00148-6.

Study record dates

Study Major Dates

• Study Start (Actual): November 27, 2022
• Primary Completion (Actual): January 18, 2025
• Study Completion (Estimated): February 28, 2026

Study Registration Dates

• First Submitted: June 14, 2021
• First Submitted That Met QC Criteria: June 22, 2021
• First Posted (Actual): June 30, 2021

Study Record Updates

• Last Update Posted (Actual): June 4, 2025
• Last Update Submitted That Met QC Criteria: May 29, 2025
• Last Verified: May 1, 2025

More Information

Terms related to this study

• Keywords: Pneumococcal conjugate vaccine; Mass vaccination; Quasi-experimental; Crisis; Humanitarian; Forced displacement
• Additional Relevant MeSH Terms: Infections; Gram-Positive Bacterial Infections; Bacterial Infections; Bacterial Infections and Mycoses; Streptococcal Infections; Pneumococcal Infections; Immunologic Factors; Physiological Effects of Drugs; Heptavalent Pneumococcal Conjugate Vaccine
• Other Study ID Numbers: OPP1211787

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Anonymised participant data will be deposited in a curated digital repository and made available subject to meeting access conditions.
• IPD Sharing Time Frame: June 2026 - May 2036
• IPD Sharing Access Criteria: Researchers wishing to apply for data should complete and submit a data application form, outlining the research purpose for which they wish to use the data, a list of variables that they wish to access, and information on how they fulfil the access conditions. If the application fulfils the eligibility criteria, the applicant will be provided with a Data Transfer Agreement that must be signed by their host organisation.
• IPD Sharing Supporting Information Type: ANALYTIC_CODE

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No