Publication

Effect of 10-valent pneumococcal conjugate vaccine on invasive pneumococcal disease and nasopharyngeal carriage in Kenya

Authored by:

Hammitt, L.L., Etyang, A.O., Morpeth, S.C. et al

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.

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Additional key concepts from this publication:

Immunization can help protect unimmunized children, adults and the elderly through herd effects.

Key Evidence: A study of the 10-strain pneumococcal conjugate vaccine in rural Kenya demonstrated herd protection. Over a 4-year period following the introduction of the vaccine for infants, coupled with a “catch-up” campaign for all children 12-59 months of age, the incidence of invasive pneumococcal disease (IPD) caused by the strains in the vaccine fell by 100% in infants less than two months of age who were too young to be vaccinated. In adults (≥ 15 years old) the incidence of IPD fell by 81% and in 5-14 year olds the incidence fell by nearly 75%. The chances of unvaccinated persons becoming ill with any strain of the disease also fell significantly – by 87% in infants under two months old, by nearly half (47%) in 5-14 year olds, and by more than one-third (37%) in adults.

Immunization can help protect unimmunized children, adults and the elderly through herd effects.

Key Evidence: 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.

From the VoICE Editors: The Gambia study publication referenced can be found at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4909992/