Large trial underway in Brazil to test efficacy of BCG revaccination in preventing TB.

2003 JAN 1 - (NewsRx.com & NewsRx.net) -- by Maria G. Essig, MS, ELS, senior medical writer - A large randomized, controlled clinical trial, the Brazilian BCG-REVAC trial, has been designed to test whether revaccination with bacillus Calmette Guerin (BCG) really prevents tuberculosis.

"The intervention studied, a second BCG vaccination, is widely used, although the World Health Organization does not recommend it on the basis of absence of evidence of protection or lack of protection," observed Mauricio L. Barreto and colleagues at the Universidade Federal da Bahia and FUNASA/Ministry of Health in Brazil. "The results of the trial will make it possible for BCG revaccination practice to be informed by evidence."

In 1996, the investigators began a pair-matched and stratified-cluster randomized, controlled trial with no placebo involving 242,401 children, aged 7-14 years, who attend 763 state schools in Salvador and Manaus, Brazil. A total of 125,403 children are enrolled in intervention schools. School health services report cases of tuberculosis to the program surveillance system while maintaining the blinded nature of the trial.

"Analysis is planned for the next 12 months, where efficacy will be estimated by calculating incidence of tuberculosis in the vaccine and control groups, taking into consideration the cluster design," said Barreto and his collaborators.

"This is an ...