Olubukola T Idoko1,2, Nuredin Mohammed1, Patrick Ansah3, Abraham Hodgson3, Milagritos D Tapia4, Samba O Sow4, Paanchali R Chowdhury5, Matthias Niedrig5, Elmar Saathoff6,7, Beate Kampmann1,8. 1. a The Vaccines and Immunity Theme, Medical Research Council Unit The Gambia at London School of Hygiene and Tropical Medicine , Fajara , The Gambia. 2. b CIHLMU Center for International Health, Medical Center of the University of Munich (LMU) , Munich , Germany. 3. c Navrongo Health Research Centre, Ghana Health Service , Navrongo , Ghana. 4. d Centre pour le Developement des Vaccins, University of Maryland , Bamako , Mali. 5. e Centre for Biologic Threats and Special Pathogens, Robert Koch Institute , Berlin , Germany. 6. f Division of Infectious Diseases and Tropical Medicine, University Hospital , LMU Munich , Germany. 7. g German Centre for Infection Research (DZIF), partner site Munich , Germany. 8. h The Vaccine Centre, London School of Hygiene and Tropical Medicine , London , England.
Abstract
Background: The World Health Organization recommends use of a single yellow fever (YF) vaccine dose for life and fractional doses in outbreaks when there are limited vaccine stocks. In endemic regions, this vaccine is given as part of routine infant immunization programs around 9 months of age. There is a need to better understand immune responses when vaccinating infants particularly in contexts where the child may be malnourished. Methods: Data from 393 Malian and Ghanaian infants who concomitantly received measles and YF vaccines at 9 to 11 months of age were retrospectively analyzed. Response to YF vaccine was examined for association with nutritional status at time of vaccination, sex, age, pre-vaccination titers and season of vaccination. Results: Neutralizing antibodies following vaccination were unaffected by season of vaccination, sex, pre-vaccination titers or nutritional status, though there was a trend to higher titers in males and children with higher height for age z-scores. Seroconversion rates differed significantly between countries (63.5 in Ghana vs. 91.0% in Mali). Conclusion: Longitudinal, prospective studies are needed to optimize the use of YF vaccine in infants in endemic settings. There may be a need for booster vaccinations and to compare various vaccine preparations to optimize the use of available vaccines.
Background: The World Health Organization recommends use of a single yellow fever (YF) vaccine dose for life and fractional doses in outbreaks when there are limited vaccine stocks. In endemic regions, this vaccine is given as part of routine infant immunization programs around 9 months of age. There is a need to better understand immune responses when vaccinating infants particularly in contexts where the child may be malnourished. Methods: Data from 393 Malian and Ghanaian infants who concomitantly received measles and YF vaccines at 9 to 11 months of age were retrospectively analyzed. Response to YF vaccine was examined for association with nutritional status at time of vaccination, sex, age, pre-vaccination titers and season of vaccination. Results: Neutralizing antibodies following vaccination were unaffected by season of vaccination, sex, pre-vaccination titers or nutritional status, though there was a trend to higher titers in males and children with higher height for age z-scores. Seroconversion rates differed significantly between countries (63.5 in Ghana vs. 91.0% in Mali). Conclusion: Longitudinal, prospective studies are needed to optimize the use of YF vaccine in infants in endemic settings. There may be a need for booster vaccinations and to compare various vaccine preparations to optimize the use of available vaccines.
Authors: Dheeraj Soni; Simon D Van Haren; Olubukola T Idoko; Jay T Evans; Joann Diray-Arce; David J Dowling; Ofer Levy Journal: Front Immunol Date: 2020-10-15 Impact factor: 7.561