José de Azevedo Lozana

Immunogenicity of WHO-17D and Brazilian 17DD yellow fever vaccines: a randomized trial

OBJECTIVE To compare the immunogenicity of three yellow fever vaccines from WHO-17D and Brazilian 17DD substrains (different seed-lots). METHODS An equivalence trial was carried out involving 1,087 adults in Rio de Janeiro. Vaccines produced by Bio-Manguinhos, Fiocruz (Rio de Janeiro, Brazil) were administered following standardized procedures adapted to allow blocked randomized allocation of participants to coded vaccine types (double-blind). Neutralizing yellow fever antibody titters were compared in pre- and post-immunization serum samples. Equivalence was defined as a difference of no more than five percentage points in seroconversion rates, and ratio between Geometric Mean Titters (GMT) higher than 0.67. RESULTS Seroconversion rates were 98% or higher among subjects previously seronegative, and 90% or more of the total cohort of vaccinees, including those previously seropositive. Differences in seroconversion ranged from -0.05% to -3.02%. The intensity of the immune response was also very similar across vaccines: 14.5 to 18.6 IU/mL. GMT ratios ranged from 0.78 to 0.93. Taking the placebo group into account, the vaccines explained 93% of seroconversion. Viremia was detected in 2.7% of vaccinated subjects from Day 3 to Day 7. CONCLUSIONS The equivalent immunogenicity of yellow fever vaccines from the 17D and 17DD substrains was demonstrated for the first time in placebo-controlled double-blind randomized trial. The study completed the clinical validation process of a new vaccine seed-lot, provided evidence for use of alternative attenuated virus substrains in vaccine production for a major manufacturer, and for the utilization of the 17DD vaccine in other countries.

Auto-avaliação de saúde e limitações físicas decorrentes de problemas de saúde

OBJECTIVE: To evaluate self-rated health and physical disabilities due to health problems. METHODS: Population-based cross-sectional study carried out in 18 Brazilian cities between 2002 and 2005. There were interviewed 26,424 residents (aged 15 years or more) of households selected by a two-stage probabilistic sampling. Percentages and confidence intervals were calculated considering the study design effects. RESULTS: Poorer self-rated health status and physical disabilities were found among women, those aged 50 years old or more and those with lower education. In addition, higher percentages of fair or poor self-rated health were found in cities in Northern and Northeastern Brazil compared to those in Southern and Southeastern Brazil. CONCLUSIONS: Poorer health conditions in the North/Northeast compared to the South/Southeast regions reflect factors related to social inequalities, mainly lower education.OBJETIVO: Avaliar a autopercepcao de saude e a presenca de limitacoes fisicas devido a problemas de saude. METODOS: Estudo transversal de base populacional realizado entre 2002 e 2005, em 18 capitais de estados do Brasil. Entrevistaram-se 26.424 moradores de 15 anos ou mais de idade em domicilios selecionados por amostra probabilistica em dois estagios. Calcularam-se percentuais e intervalos de confianca considerando-se os efeitos do desenho do estudo. RESULTADOS: Os resultados mostraram que as piores condicoes de saude sao referidas por mulheres, individuos com 50 anos ou mais e com menor grau de escolaridade. Os percentuais relacionados a percepcao de saude regular ou ruim foram maiores nas cidades das regioes Norte e Nordeste quando comparados aos das cidades das regioes Sul e Sudeste. CONCLUSOES: As piores condicoes de saude das regioes Norte/Nordeste comparadas as das regioes Sul/Sudeste revelam um conjunto de fatores relacionados as desigualdades sociais, entre os quais o menor grau de escolaridade.