CONICET | Buscador de Institutos y Recursos Humanos

USING A DETERMINISTIC MATHEMATICAL MODEL TO EVALUATE THEIMPACT OF ALTERNATIVE VACCINATION STRATEGIES ON PERTUSSIS INCIDENCEBERGERO P1 ; PESCO P1 ; FABRICIUSG1 ; HOZBOR D21Instituto de InvestigacionesFisicoqu.micas Teóricas y Aplicadas, Facultad de Ciencias Exactas, UniversidadNacionalde La Plata, CC 16, Suc. 4, 1900 La Plata,Argentina, 2Laboratorio VacSal. Instituto de Biotecnolog.a yBiolog.a Molecular, Departamento de CienciasBiol.gicas, Facultad de Ciencias Exactas, Universidad Nacional deLa Plata y CCT-La Plata, CONICET. Calles 47 y115 (1900) La Plata, Argentina.Objective Strategies such aschanges in vaccination schedules, improvement in coverage, and avoiding delayedadministrationcould be implemented to improve the control of pertussis ininfants. To assess the potential impact ofsuch strategies, we use mathematical modeling andepidemiological data.Material and Methods We used anage-structured deterministic mathematical model developed by us [1,2]. Thepopulation dynamicsis described transferring individuals among epidemiologicalclasses that differ in immune and infectious status.Since the model incorporates the age specific coverage foreach dose we could evaluate the changes in both cov11thInternational Bordetella Symposium | 55 erage and age ofadministration. To analyze the timing of vaccination we considered the 4schedules most widelyused: 2-4-6 months (mo), 6-10-14 weeks (w), 2-3-4 mo and3-4-5 mo. To evaluate the effect of delays on infantincidences, we included vaccination profiles from La Plata,Argentina.Results We found that achange from 2-4-6mo schedule to 6-10-14w decreases the infant incidences by40%. Furthermore,we observed that the change from 2-4-6 mo to 2-3-4 modecreases the incidences by 30%, while changingfrom 2-4-6 mo to 3-4-5mo increases it by 5%.This new result is in agreement with our previous findings:avoiding delays in primary vaccination cause a strongreduction in infant incidences [2]. In regions with highcoverage, the adherence to recommended vaccinationschedule without delay decreases the incidence by 20%.Similarly, evolving from a situation with 80% coveragewith delay to a stage with 95% coverage without delay,decreases the incidence by 40%.Conclusion Our results point outthe magnitude of the reduction of incidence in infants that could be achievedby adoptingan early schedule, with high vaccine coverage and shorterdelays.[1] Fabricius G et al. Epidem. Inf. 141, 718(2013)[2] Pesco P et al. Vaccine 33, 5475(2015)