Revaccination with BCG: its effects on skin tests in Kuwaiti senior school children.
نویسندگان
چکیده
Following a policy of BCG vaccination adopted in Kuwait more than 20 yrs ago, children receive their first vaccination just before starting school. Those who have a response of less than 10 mm induration to 2 tu of RT23 PPD, when they are 13 yrs old, are revaccinated. The effects of this revaccination on skin test positivity in a group of 18 yr old senior school children have been investigated. In a random study group 23% were found to have received BCG a second time. Revaccination resulted in a significant increase in positivity to tuberculin, and to the other 6 reagents tested, that was much more than would have been expected due to the passage of time alone in low responders. Scars of the second BCG vaccination were larger than those after the first vaccination, and showed a sex difference, with scars being significantly larger in boys than in girls. Boys also tended to show the largest responses to skin tests, with the notable exception of tuberculin to which girls showed the largest response. In most cases responses to skin tests were larger after revaccination than after a single vaccination. Based on this study, it is impossible to be sure that revaccination improved protective immunity, but the increase in tuberculin responsiveness, and recognition of environmental mycobacterial species may be indirect evidence supporting this conclusion.
منابع مشابه
Tuberculin reactivity in a population of schoolchildren with high BCG vaccination coverage.
OBJECTIVE To investigate the influence of BCG vaccination or revaccination on tuberculin skin test reactivity, in order to guide the correct interpretation of this test in a setting of high neonatal BCG vaccination coverage and an increasing BCG revaccination coverage at school age. METHODS We conducted tuberculin skin testing and BCG scar reading in 1 148 children aged 7-14 years old in the ...
متن کامل[BCG revaccination in school children: evolution of the lesion at the vaccination site between 48 hours and 10 weeks].
OBJECTIVE Cutaneous reaction after BCG revaccination has been cause of concerns due its magnitude. Would it be intense enough to discourage its use in school-age children? The objective of this study is to describe the evolution of BCG vaccination site between 48 hours and 10 weeks post-revaccination. METHODS A descriptive cohort study was carried out involving 484 children between six and 11...
متن کاملMaking wider use of the world's most widely used vaccine: Bacille Calmette–Guérin revaccination reconsidered
Approximately 100 million newborn children receive Bacille Calmette-Guérin (BCG) annually, because vaccination is consistently protective against childhood tuberculous meningitis and miliary TB. By contrast, BCG efficacy against pulmonary TB in children and adults is highly variable, ranging from 0% to 80%, though it tends to be higher in individuals who have no detectable prior exposure to myc...
متن کاملBCG Revaccination Does Not Protect Against Leprosy in the Brazilian Amazon: A Cluster Randomised Trial
BACKGROUND Although BCG has been found to impart protection against leprosy in many populations, the utility of repeat or booster BCG vaccinations is still unclear. When a policy of giving a second BCG dose to school children in Brazil was introduced, a trial was conducted to assess its impact against tuberculosis, and a leprosy component was then undertaken in parallel. OBJECTIVE to estimate...
متن کامل[Continuing or discontinuing BCG revaccination in adolescents].
BCG revaccination was introduced in Brazil in the mid-90's but no study has evaluated vaccine coverage through direct assessment of the scar. BCG scars were assessed in 2,785 public school adolescents, aged 13 to 14 years, in Southeastern Brazil, between September 2001 and May 2002. The prevalence rate of revaccination was 64.3% (95% CI: 62.5-66.0). Despite the efforts to implement and sustain ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- The European respiratory journal
دوره 3 2 شماره
صفحات -
تاریخ انتشار 1990