|dc.description.abstract||ACKGROUND AND OBJECTIVE:
Streptococcus pneumoniae is a leading cause of mortality before age 5, but few studies examine details of childhood response to pneumococcal vaccine in
less-developed settings. Although malnutrition, HIV, and concurrent infections can impair
response, evidence suggests that chronic parasitic infections can also contribute to poor
vaccination results. The objective of this study was to determine whether response to
pneumococcal vaccine varied among children either exposed to parasitic infections in
utero, previously infected in infancy, or infected at the time of immunization.
Children from a 2006 to 2010 maternal–infant cohort were eligible for the current
study. Children were screened for malaria, schistosomiasis, filariasis, intestinal helminths, and protozoa. Data on in utero exposure and early life infections were linked, and baseline antipneumococcal immunoglobulin G levels and nasopharyngeal carrier status were determined. Participants received decavalent pneumococcal vaccine, and 4 weeks later, serology was repeated to assess vaccine response.
A total of 281 children were included. Preimmunity was associated with greater
postvaccination increments in anti–pneumococcal polysaccharide immunoglobulin G,
especially serotypes 4, 7, 9, 18C, and 19. Present-day growth stunting was independently associated with weaker responses to 1, 4, 6B, 7, 9V, and 19. Previous exposure to Trichuris was associated with stronger responses to 1, 5, 6B, 7, 18C, and 23, but other parasite exposures were not consistently associated with response.
In our cohort, hyporesponsiveness to pneumococcal conjugate vaccine was
associated with growth stunting but not parasite exposure. Parasite-related vaccine
response deficits identified before age 3 do not persist into later childhood.||en_US