Whooping cough - theoretical evaluation of new vaccination strategies in São Paulo - Brazil / Avaliação de novas estratégias vacinais contra a coqueluche no município de São Paulo

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

Background: Whooping cough is a respiratory tract infection caused by Bordetella pertussis and characterized by paroxysmal cough that usually causes complications for infants, including death, and for people with chronic respiratory diseases. Immunity against pertussis after infection or vaccination is not everlasting. Despite of high childhood immunization coverage and the disease control from the 50 s to 80 s, since late 80 s developed countries notified high levels of pertussis in adolescents and adults. This reappearance has not being detected in Brazil yet, but at least one formal study has demonstrated the possibility of this change in the next years. Objective: Evaluating new pertussis vaccine s booster for adolescents and adults in São Paulo city. Methods: Development of a deterministic, compartmental and age-dependent model accounting for immunity waning. The data was retrieved from literature, Surveillance Center of the State of São Paulo (CVE), and the Brazilian national health data system (DATASUS). Data manipulation used Berkeley Madonna® and Microsoft Excel®. Vaccination strategies included the current vaccination scheme, plus (i) 10%, 35%, 45% or 70% vaccine coverage for those at the age of 12 and (ii) both 35% and 70% vaccine coverage at the ages 12 and 20, respectively. The Who Acquire Infection from Whom (WAIFW) matrices method was used to assume age related transmission rates. Sensitivity analysis was performed. Results: Booster vaccination for 12 years youths, at 10% coverage, yields disease reduction only among adolescents (10 to 19 years); coverage up to 35% yields disease reduction for all ages; at 35%, 45% and 70% coverage, the reduction achieves 59%, 65% and 73%. Booster vaccination at 12 and 20 years, with coverage at 35% and 70% respectively, yields 62% cases reduction. Discussion: Results suggest that adolescent s vaccine booster could reduce pertussis occurrence for all ages, including infants, as also demonstrated by other authors. In contrast, only one vaccine booster for adults (20 years) achieves insignificant results. In conclusion, we have been able to demonstrate that, in São Paulo, the adolescent vaccine booster strategy is a promising police to further reduce whooping cough occurrence. However, cost effective analysis and other adults vaccination strategies are recommended.

ASSUNTO(S)

pertussis vaccine whooping cough adult adolescent models adolescentes adultos theoretical coqueluche modelos teóricos vacina contra coqueluche

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