A study in rural Kenya, over a 4-year period following the introduction of the 10-strain pneumococcal conjugate vaccine for infants, that included a catch-up vaccination campaign for children 12-59 months of age, suggests that the catch-up vaccination for older birth cohorts may have been a key factor in protecting unvaccinated individuals and speeding up the reduction of the disease in the community. In contrast, a study in The Gambia, where no catch-up campaign took place, found no herd effects during the first three years following the introduction of PCV-13 for infants.
The Gambia study publication referenced can be found at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4909992/
Full Citation:
Hammitt, L.L., Etyang, A.O., Morpeth, S.C. et al. 2019. Effect of 10-valent pneumococcal conjugate vaccine on invasive pneumococcal disease and nasopharyngeal carriage in Kenya. Lancet. 393.
Title of Article: Effect of 10-valent pneumococcal conjugate vaccine on invasive pneumococcal disease and nasopharyngeal carriage in Kenya
Author(s): Hammitt, L.L., Etyang, A.O., Morpeth, S.C. et al
Publication Year: 2019
Publication Name: Lancet
Publication Volume: 393
Publication Source URL: https://pubmed.ncbi.nlm.nih.gov/31000194/
DOI (Digital Object Identifier): 10.1016/S0140-6736(18)33005-8
Topics: Health
Disease Vaccines: Pneumococcal disease/PCV/PPSV | Pneumonia
Immunization Terms: Herd effects
Countries: Kenya
WHO Regions: Africa