London School of Hygiene & Tropical Medicine
Department of Infectious Disease Epidemiology
Epidemiologist and infectious disease modeller at the London School of Hygiene & Tropical Medicine with a strong focus on answering policy-relevant questions in relation to (pneumococcal) disease transmission and vaccine strategies. Over eight years of experience in programming, data science, and web-development. His research predominantly focuses on identifying alternative vaccination strategies that can effectively and feasibly be used to deliver PCVs in humanitarian crises.

Presenter Of 1 Presentation


Session Type
Parallel Session
Mon, 20.06.2022
Session Time
15:20 - 16:35
Grand Ballroom West
Lecture Time
15:25 - 15:35



Despite a likely high disease burden, pneumococcal conjugate vaccines (PCVs) are rarely used in humanitarian crises. Routine immunization is rarely feasible, and there is little evidence on alternative delivery strategies. We aimed to identify strategies that quickly reduce and sustain low transmission of vaccine serotypes.


In a camp for internally displaced persons (IDP) in Somaliland, we conducted a nested carriage and contact survey to parameterise a transmission model assessing the potential effect and optimal age targeting of PCVs campaigns. We extrapolated this model to other representative humanitarian crises settings: an acute-phase IDP camp, a protracted crisis in a rural setting, and an urban setting with mixed IDP and host communities. For each we explored the impact and efficiency of campaigns with different target age-groups and dosing-strategies.


Results from the carriage and contact survey are reported in another abstract. For the Somaliland IDP camp our model projects that a single PCV campaign including children <5 years can temporarily establish substantial herd-protection, avoiding 33% of infant vaccine type infections in in the 5 years following the campaign. Extended age-eligibility to children up to 10 or 15 years old could further increase this impact by 49% and 60%. High migration rates and close contact with unvaccinated host populations reduce the impact and may require wider age-targeting and more frequent repeat campaigns until routine services can be (re-)established.


We show that PCV campaigns can be an effective option to reduce the burden of pneumococcal disease in humanitarian crises until routine immunisation can be implemented.