Details

Autor(en) / Beteiligte

• Andrade, Ana Lucia
• da Silva Vieira, Maria Aparecida
• Minamisava, Ruth
• Toscano, Cristiana Maria
• de Lima Souza, Menira Borges
• Fiaccadori, Fabíola
• Figueiredo, Cristina Adelaide
• Curti, Suely Pires
• Nerger, Maria Lígia Bacciotte Ramos
• Bierrenbach, Ana Luiza
• Sartori, Ana Marli
• Domingues, Carla Magda Alan
• Ribeiro, Circéa Amália
• Santiago, Cristina
• das Dôres de Paula Cardoso, Divina
• Alves de Oliveira, Elisabete
• Policena, Gabriela
• Sato, Helena Keico
• Novaes, Hillegonda Maria
• Zanata, Ivete Favaron Lopes
• Mieko, Julia
• Galdino de Oliveira, Leandro Luís
• Tomich, Lísia Moura
• de Oliveira, Maria Isabel
• Puccini, Rosana
• Reis, Rosana
• do Nascimento, Selma Salvador
• Barbosa, Tamyres Fernanda
• Cesare, Wandy Lutz

Titel

Single-dose varicella vaccine effectiveness in Brazil: A case-control study

Ist Teil von

• Vaccine, 2018-01, Vol.36 (4), p.479-483

Ort / Verlag

Netherlands: Elsevier Ltd

Erscheinungsjahr

2018

Quelle

MEDLINE

Beschreibungen/Notizen

• •Single-dose varicella vaccine is highly effective against moderate/severe varicella.•Breakthrough varicella was mostly associated to milder cases.•Monitoring breakthrough and outbreaks is advisable for the 2nd dose recommendation. Varicella vaccine was introduced into the Brazilian Immunization Program in October 2013, as a single-dose schedule administered at 15 months of age. Its effectiveness had not yet been assessed in the country. A matched case-control study was carried out in São Paulo and Goiânia (Southeast and Midwest regions, respectively), Brazil. Suspected cases, were identified through a prospective surveillance established in the study sites. All cases had specimens from skin lesion collected for molecular laboratory testing. Cases were confirmed by either clinical or PCR of skin lesions and classified as mild, moderate, and severe disease. Two neighborhood controls were selected for each case. Cases and controls were aged 15–32 months and interviewed at home. Evidence of prior vaccination was obtained from vaccination cards. Univariate and multivariate logistic regression models were used, and odds ratio and its respective 95% confidence intervals were estimated. Vaccine effectiveness was estimated by comparing de odds of having received varicella vaccine among cases and controls. A total of 168 cases and 301 controls were enrolled. Moderate and severe illness, was found in 33.3% and 9.9% of the cases. Effectiveness of a single dose varicella vaccine was 86% (95%CI 72–92%) against disease of any severity and 93% (95%CI 82–97%) against moderate and severe disease. Out of 168 cases, 81.8% had positive PCR results for wild-type strains, and 22.0% were breakthrough varicella cases. Breakthrough cases were milder compared to non-breakthrough cases (p < .001). Effectiveness of single dose varicella vaccine in Brazil is comparable to that in other countries where breakthrough varicella cases have also been found to occur. The goal of the varicella vaccination program, along with disease burden and affordability should be taken into consideration when considering the adoption of a second dose of varicella vaccine into national immunization programs.