Mass Campaigns With Fractional Dose Pneumococcal Vaccines in Sub-Saharan Africa (fPCV)

Summary

The aim of this study is to assess the impact of a mass campaign with a single, fractional dose of Pneumosil®, a PCV10, on VT carriage. A 20% fractional dose (1/5th) will be used as a practical formulation to prepare and administer. This study will assess whether the impact of a single fractional dose mass campaign on carriage is non-inferior to a single full dose mass campaign in a cluster randomized trial in a low coverage setting in Niger. The results would provide evidence of the population-level direct and indirect impact of fractional dose in older children which will be completed by mathematical modelling, to inform the policy debate regarding PCV dosing schedules in different contexts. This trial and the modelling exercises that follow, would allow for larger scale evaluation of fractional dose PCV strategies in multiple contexts.

Timeline

Start

2021-12-30

Primary completion

2023-03-14

Completion

2023-10-03

Outcome

Met primary endpoint

paper The primary analysis showed a risk difference of -16·2% (95% CI -28·6 to -3·0) between the full-dose group and control group (p=0·002 for superiority) PMID 39798587 ↗

paper -3·8% (-6·1 to -1·6) between the full-dose group and fractional-dose group, meeting the non-inferiority criteria. PMID 39798587 ↗

Publications

• Coldiron ME, Soumana I, Baudin E, Langendorf C, Mamiafo Tchoula C, Brah S, Karani A, Gallagher KE, Kagucia EW, Scott JAG, Grais RF. Effect of mass campaigns with full and fractional doses of pneumococcal conjugate vaccine (Pneumosil) on the reduction of nasopharyngeal pneumococcal carriage in Niger: a three-arm, open-label, cluster-randomised trial. Lancet Infect Dis. 2025 Jun;25(6):634-642. doi: 10.1016/S1473-3099(24)00719-9. Epub 2025 Jan 8.

Drugs

Evaluation	Drug	Modality	Dose	Route
Subject	Pneumosil	Vaccine	20 %	—

Indications

No indication recorded.