Article

Comparative Tuberculosis (TB) Prevention Effectiveness in Children of Bacillus Calmette-Guérin (BCG) Vaccines from Different Sources, Kazakhstan

University of Otago, New Zealand
PLoS ONE (Impact Factor: 3.53). 03/2012; 7(3):e32567. DOI: 10.1371/journal.pone.0032567
Source: PubMed

ABSTRACT Except during a 1-year period when BCG vaccine was not routinely administered, annual coverage of infants with Bacillus Calmette-Guérin (BCG) in Kazakhstan since 2002 has exceeded 95%. BCG preparations from different sources (Japan, Serbia, and Russia) or none were used exclusively in comparable 7-month time-frames, September through March, in 4 successive years beginning in 2002. Our objective was to assess relative effectiveness of BCG immunization.
We compared outcomes of birth cohorts from the 4 time-frames retrospectively. Three cohorts received vaccine from one of three manufacturers exclusively, and one cohort was not vaccinated. Cohorts were followed for 3 years for notifications of clinical TB and of culture-confirmed TB, and for 21 months for TB meningitis notifications. Prevention effectiveness based on relative risk of TB incidence was calculated for each vaccinated cohort compared to the non-vaccinated cohort. Although there were differences in prevention effectiveness observed among the three BCG vaccines, all were protective. The Japanese vaccine (currently used in Kazakhstan), the Serbian vaccine, and the Russian vaccine respectively were 69%, 43%, and 22% effective with respect to clinical TB notifications, and 92%, 82%, and 51% effective with respect to culture confirmed TB. All three vaccines were >70% effective with respect to TB meningitis.
Potential limitations included considerations that 1) the methodology used was retrospective, 2) multiple risk factors could have varied between cohorts and affected prevention effectiveness measures, 3) most cases were clinically diagnosed, and TB culture-positive case numbers and TB meningitis case numbers were sparse, and 4) small variations in reported population TB burden could have affected relative risk of exposure for cohorts.
All three BCG vaccines evaluated were protective against TB, and prevention effectiveness varied by manufacturer. When setting national immunization policy, consideration should be given to prevention effectiveness of BCG preparations.

0 Followers
 · 
115 Views
  • Clinical Infectious Diseases 05/2014; 59(4). DOI:10.1093/cid/ciu329 · 9.42 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The road to a more efficacious vaccine that could be a truly transformative tool for decreasing tuberculosis morbidity and mortality, along with Mycobacterium tuberculosis transmission, is quite daunting. Despite this, there are reasons for optimism. Abetted by better conceptual clarity, clear acknowledgment of the degree of our current immunobiological ignorance, the availability of powerful new tools for dissecting the immunopathogenesis of human tuberculosis, the generation of more creative diversity in tuberculosis vaccine concepts, the development of better fit-for-purpose animal models, and the potential of more pragmatic approaches to the clinical testing of vaccine candidates, the field has promise for delivering novel tools for dealing with this worldwide scourge of poverty. © 2015 The Authors. Immunological Reviews Published by John Wiley & Sons Ltd.
    Immunological Reviews 03/2015; 264(1). DOI:10.1111/imr.12270 · 12.91 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Tuberculosis (TB) is one of the oldest diseases known to mankind, yet it is the second leading cause of death from an infection worldwide today. In the absence of epidemi- ological data, TB in children was not considered signific- ant and research efforts did not prioritise this group. More recently, there has been renewed interest in childhood TB, leading to improved understanding of the fundamental dif- ferences between children and adults in relation to both TB infection and disease. Children with TB infection have a high risk of rapid progression to disease which leads to challenges in diagnosis but also offers the opportunity to investigate biomarkers for infection, progression and pro- tection. This review discusses the most relevant advances in the understanding of epidemiology, diagnosis and pre- vention of children with TB. It also highlights challenges and research priorities in childhood TB, which include bet- ter diagnostic tests, accurate correlates of protection and an improved vaccine.
    Swiss medical weekly: official journal of the Swiss Society of Infectious Diseases, the Swiss Society of Internal Medicine, the Swiss Society of Pneumology 09/2014; 144:w14000. DOI:10.4414/smw.2014.14000 · 1.88 Impact Factor

Full-text (2 Sources)

Download
51 Downloads
Available from
Jun 1, 2014