Vaccine 33 (2015) 1562–1567View metadata, citation and similar papers at to you byContents lists available at ScienceDirectVaccinejournal homepage: manifestations of leprosy after BCG vaccination: Anobservational study in BangladeshRenate A. Richardus a , C. Ruth Butlin b , Khorshed Alam b , Kallyan Kundu b ,Annemieke Geluk c , Jan Hendrik Richardus a, aDepartment of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The NetherlandsRural Health Program, The Leprosy Mission International Bangladesh, Nilphamari, BangladeshcDepartment of Infectious Diseases, Leiden University Medical Center, Leiden, The Netherlandsba r t i c l ei n f oArticle history:Received 6 December 2014Received in revised form 16 January 2015Accepted 5 February 2015Available online 18 February 2015Keywords:LeprosyBCGContactsM. lepraePreventionProphylaxisa b s t r a c tBackground: Although BCG is used as a vaccine against tuberculosis, it also protects against leprosy.Previous evaluation over 18 years of an intervention of two doses BCG for 3536 household contacts ofleprosy patients showed that 28 (23%) out of 122 contacts diagnosed with leprosy, developed symptoms2–10 months after vaccination. This study describes contacts of leprosy patients in Bangladesh whodeveloped leprosy within 12 weeks after receiving a single BCG dose.Methods: A cluster RCT in Bangladesh aims to study the effectiveness of the BCG vaccine versus BCG incombination with single dose rifampicin (SDR) given 2 to 3 months after BCG, in the prevention of leprosyamong contacts of newly diagnosed leprosy patients. During the first 1,5 years of this ongoing trial weidentified contacts who developed leprosy within the first 12 weeks after receiving BCG vaccination, thetimeframe before SDR is given.Results: We identified 21 contacts who developed leprosy within 12 weeks after BCG vaccination among5196 vaccinated contacts (0.40%). All 21 cases presented with paucibacillary (PB) leprosy, including children and adults. About half of these cases had previously received BCG vaccination as indicated by thepresence of a BCG scar; 43% presented with signs of nerve function impairment and/or Type 1 (reversal)reaction, and 56% of the index patients had multibacillary (MB) leprosy.Conclusion: An unexpectedly high proportion of healthy contacts of leprosy patients presented with PBleprosy within 12 weeks after receiving BCG vaccination, possibly as a result of boosted cell-mediatedimmunity by homologues of Mycobacterium leprae antigens in BCG. Various immunological mechanisms could underlie this phenomenon, including an immune reconstitution inflammatory syndrome(IRIS). Further studies are required to determine whether BCG vaccination merely altered the incubationperiod or actually changed the course of the infection from self-limiting, subclinical infection to manifestdisease. 2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-NDlicense ).1. IntroductionMycobacterium bovis Bacillus Calmette-Guérin (BCG) remainsthe only available vaccine against tuberculosis (TB) today. It is routinely administered to infants in many countries worldwide andconfers significant protection against severe forms of TB, mostlymiliary and meningeal in young infants. BCG-induced immunityhas been shown to decline with time and is generally thought tolast no more than 10–15 years, differs between ages and endemic Corresponding author. Tel.: 31 10 7038473.E-mail address: [email protected] (J.H. Richardus).COREprovided by Elsevier - Publisher Connectorareas, and offers poor protection against contagious pulmonary TBin adulthood [1–4].Despite being known primarily as a vaccine against TB, BCG alsoprotects against leprosy (caused by Mycobacterium leprae), especially when given to household contacts of leprosy patients [5,6]. Infact, to date, BCG has been shown to be the best available vaccine forprevention of leprosy, superior to other mycobacterium containingvaccines, including combination vaccines with BCG and M. lepraespecific vaccines [7,8]. The rationale for the use of BCG as a vaccineagainst leprosy relies on the occurrence of many highly homologous antigens present in the M. bovis genome (the progenitor for theBCG vaccine) and the M. leprae and the Mycobacterium tuberculosisgenomes [9,10], which induce cross-reactive, protective immuneresponses to M. leprae following BCG 15.02.0170264-410X/ 2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license ).

R.A. Richardus et al. / Vaccine 33 (2015) 1562–1567Because of BCG’s protective effects against leprosy, Brazil hasofficially recommended BCG since the early 1970s for householdcontacts of leprosy cases, as a boost to routine BCG vaccination innew-borns as a TB prophylactic vaccine. Since 1991, the BrazilianMinistry of Health has advised two doses of BCG to be administeredto both current household contacts and contacts of index caseswho were diagnosed within the previous five years. This policy wasassessed in a cohort study of 3536 contacts of 1161 leprosy patientsin Brazil [11], showing that the protection conferred by a boosterBCG vaccination was 56% and was not substantially affected by previous BCG vaccination. Among the 122 new cases detected during18 years of contact follow-up, leprosy was diagnosed in 28 of thesecontacts (23%) relatively soon after vaccination (2–10 months). Dueto incomplete follow-up, the study needs to be interpreted withcaution, and in particular the increased risk of tuberculoid leprosyin the first months after BCG vaccination needs further substantiation.The COLEP study in Bangladesh showed that the use of a singledose of rifampicin (SDR) in contacts of newly diagnosed leprosypatients reduced the overall incidence of leprosy in the first twoyears by 57% [12]. Furthermore, this study showed that the effectof SDR depended on the BCG status of the contact: If the contacthad received BCG vaccination as part of a childhood vaccinationprogram (as established by the presence of a BCG-scar), the protective effect of SDR was 80% [13]. And if not, the protective effect ofBCG alone was 57%.In view of the above findings regarding BCG vaccine and SDR incontacts of leprosy patients, a cluster randomized controlled trialwas initiated in Bangladesh in 2012 with the aim to study the effectiveness of the BCG vaccine versus BCG in combination with SDRgiven 2 to 3 months after BCG, in the prevention of leprosy amongcontacts of newly diagnosed leprosy patients [14]. In this trial special attention is given to the occurrence of clinical manifestationsof leprosy in the first 12 weeks after the contacts received BCG vaccination, the timeframe before SDR is given. Here we report theoccurrence of 21 cases of leprosy (among 5196 vaccinated contacts) during this first period after BCG vaccination and describethe characteristics of these patients and their disease symptoms.Furthermore, the possible underlying immunological mechanismsand implications for public health practice are discussed.2. MethodsThe study is part of the MALTALEP trial [14] that is currentlyconducted in the districts of Nilphamari, Rangpur, Thakurgaonand Panchagarh in northwest Bangladesh. Leprosy patients arerecruited into the trial through the Rural Health Program (RHP)of The Leprosy Mission International Bangladesh (TLMIB), locatedin Nilphamari; a referral centre specialized in the detection andtreatment of leprosy. The population of the four districts is around7000,000 (2011 census [15]) and approximately 600 new leprosypatients were detected per year between 2011 and 2013. The population in the four districts is mainly rural, but also includes six maintowns.The MALTALEP trial is a cluster randomized controlled trial. Theaim is to study the effectiveness of the BCG vaccine alone versusBCG in combination with single-dose rifampicin (SDR) in the prevention of leprosy among contacts of newly diagnosed leprosypatients. Full details of the trial protocol were described previously[14]. In summary, contact groups of approximately 15 persons areestablished for each of the 1300 newly diagnosed leprosy patients(index cases) included in the trial, which will result in roughly20,000 contacts in total. The contact groups are divided randomlyover the two arms of the trial with approximately 10,000 contactseach. Contacts who have been diagnosed with leprosy in the past,1563are diagnosed at the intake examination (i.e. co-prevalent cases)or are clinically considered to be leprosy suspects at intake examination, are excluded from the trial. All contacts are screened bytrained and experienced health workers at intake, to ensure theyhad no apparent signs of leprosy at the time of intake. After writteninformed consent was obtained, BCG was administered to all subjects (i.e. healthy contacts) followed by SDR 8–12 weeks later inthe intervention group. Subsequent follow-up takes place one yearand two years after intake. The primary outcome is the occurrenceof clinical leprosy within two years of intake. Individuals who aresuspected to have leprosy at any of the follow-up time points orwho present to a health clinic between follow-ups are sent to thespecialized leprosy hospital in Nilphamari or a local clinic for confirmation of their disease by a specialist clinician and for treatment.Intake for the trial was started in August 2012 and is expected tobe completed in 2015.In this paper we report on incidental observations during theongoing trial of all new leprosy cases among healthy contacts whowere diagnosed within 12 weeks after receiving BCG (and beforereceiving SDR) between December 2012 and May 2014. We presentdemographic and clinical data of the patients as recorded in ourdatabase as a routine procedure for the purpose of the trial.3. ResultsA total of 21 contacts (0.40%) were diagnosed with leprosywithin 12 weeks after receiving BCG vaccination, out of 5196 contacts who had received BCG and were screened after 8–12 weeks.Table 1 shows the characteristics of the healthy contacts whodeveloped leprosy within 12 weeks after BCG vaccination. Of thesecontacts, 10 (48%) were male and 11 (52%) female. Table 2 shows thecharacteristics of the contacts who received BCG vaccination butwho did not develop leprosy. The differences between the groupsdo not show statistical significance (P 0.05) due to the low numberof contacts with leprosy, but some of the observed group characteristics are worth noting. The male-female distribution is also nearlyequal in this group (47% and 53%, respectively). The average ageat registration was 29 years (range: 10–70 years) among the contacts who developed leprosy, and 28 years (range: 5–90 years) inthe group of contacts who did not develop leprosy. There were 8children ( 5 to 16 years of age) who developed leprosy within 12weeks after BCG vaccination, representing 38% of the new cases.Among the contacts who did not develop leprosy, 34% were children. Nine (43%) of the new patients were household contacts to theindex patient, sharing either the same kitchen or roof, or both. Theremaining 12 (57%) were direct neighbours of the index patient. Inthe group of contacts who did not develop leprosy, 31% were household contacts of the index patient, a lower proportion. Nine contactswho developed leprosy (43%) were known to be blood relatives tothe index patient, 3 were other relatives (unclear if blood relative ornot), or in-laws. In the group of contacts who did not develop leprosy, 25% were blood relatives to the index patient. Twelve (57%)contacts developing leprosy had probably received BCG for the firsttime or no sufficient response was induced upon initial vaccination,since no BCG scar was observed. The other 9 (43%) had a BCG scarand were thus revaccinated. In the group of contacts that did notdevelop leprosy, the proportion with a BCG scar was higher (56%).These differences are also apparent in the proportion of leprosyamong household contacts (0.55%) and neighbours (0.34%), bloodrelated (0.69%) and not blood related relatives (0.30%), and thosewith (0.31%) and without (0.53%) a BCG scar (Table 2).The average time from BCG to first suspicion of leprosy by thefield staff was 9 weeks (range: 3–11 weeks) (Table 1). Two of thesecontacts came to a clinic on their own initiative before the plannedfollow-up time, because they detected leprosy patches themselves

1564R.A. Richardus et al. / Vaccine 33 (2015) 1562–1567Table 1Characteristics of new cases of leprosy among contacts within 12 weeks of BCG vaccination.Contact no.AgeSexBloodrelation toindex*Contactlevel**BCG scar(Y/N)Time from BCGto patient firstnoticing patch(in weeks)Time from BCGto firstsuspicion ofleprosy byclinician (inweeks)Smear result(BI)Classification(Ridley 5341235382715161212122260FFFMFMFFMMFFMFFMMMMMFNN YNYNYNYYN YNNNYYN NNNYNNNYNYNNNYNNNYYNNNNNNNNNYYNNNYNNNNNNY***Blood related contact: child (son/daughter), parent (father/mother), brother or sister; Other relative: unclear if blood related or not.H: household contact; sharing either the same roof or kitchen, or both; N: neighbour living next door to patient‘s house.Table 2Characteristics of contacts with leprosy within 12 weeks after BCG vaccination, compared to those contacts who received BCG vaccination but who did not develop leprosy.ContactcharacteristicsNumberMaleFemale 16 years 16 yearsHousehold contact*Neighbour**Blood relatedNot blood related or unknownBCG scarNo BCG scarAverage age at registration**********Contacts with leprosyContacts without leprosyAll contactsContacts with leprosy****N%***N%***N%***21101181391291291229 years–4852386243574357435728 460.380.550.340.690.300.310.53Household contact: sharing either the same roof or kitchen, or both.Neighbour next to patient. 2 test: none of the differences in percentages between the two groups are statistically significant (P 0.05).Contacts that developed leprosy in each subgroup as a percentage of the total number of contacts in the same subgroup.(3 and 9 weeks after BCG). When asking the contacts how long afterhaving received BCG the patch had appeared, 7 contacts could notprovide a clear answer as to when they first discovered a patchor they had only noticed it at follow-up time point when the staffpointed it out. The remaining 14 recalled having first seen the patchbetween 2 and 11 weeks after receiving BCG, although few couldrecollect an accurate date. All contacts with leprosy were classifiedas paucibacillary (PB). According to the Ridley–Jopling classification[16], 6 (29%) contacts were classified as tuberculoid (TT), 12 (57%)as borderline tuberculoid (BT), and 3 (14%) as indeterminate (I). Sixcontacts (29%) presented with nerve involvement, but only one haddisability (partial foot drop). This contact (No. 9 in Table 1) assertedthat the foot drop was present before BCG vaccination, but it wasnot noted by the staff at contact registration time. Possibly he wasa co-prevalent case incorrectly registered at intake. The fact that hedid not recover on steroids indicates that it was possibly a late-stagenerve function impairment. All known skin smears were negative,two contacts refused skin smears (because of young age).Of the 21 contacts who developed leprosy after BCG, 4 (19%)had Type 1 (or reversal) reaction requiring steroids on initial presentation, including the patient described above with neuritis andpartial foot drop. Three other patients (14%) who had no nerveinvolvement presented with a red, hot, swollen, anaesthetic patchindicating a mild Type 1 reaction. One of these had a second episodeof reaction during the study requiring steroids and responded well.In July 2014, 6 of the contacts completed multidrug therapy withouthaving any signs of reaction. Others were still on treatment.Table 3 shows the characteristics of the 18 index patients ofthe contacts diagnosed with leprosy in the first 12 weeks afterBCG vaccination. In the case of two index patients, multiple contacts were found with leprosy within 12 weeks (2 and 3 contacts,respectively). Of the remaining 16 index patients each had one contact that developed leprosy. The average age at registration of theindex patient was 33 years (of which 3 index cases were youngerthan 16 years). This resembles closely the average age (35 years) ofall new patients that were registered by the Rural Health Program

R.A. Richardus et al. / Vaccine 33 (2015) 1562–15671565Table 3Characteristics of the index cases according to new cases found among healthy contacts (see Table 1 for serial number of the new cases).Index patient no.Contact ion(Ridley–Jopling)Smear result(BI)Duration ofsymptomsbeforediagnosis (inmonths)No. of contactsfound at intakewho ever hadleprosyNo. ofco-prevalentcases (contactsfound withleprosy 00000Not taken006000361272Not 120Not available480300101415161718in 2013 (data not shown). Among the index patients 8 (44%) weremale and 10 (56%) female. In the group of all patients registeredin 2013, the percentage of males and females was nearly equal. Of18 index patients, 8 (44%) were classified as PB and 10 (56%) asMB leprosy. In the group of all patients registered in 2013, thesepercentages were the other way around, 66% and 34% for PB andMB, respectively. According to the Ridley-Jopling classification, allindex patients were BT, except for one borderline lepromatous (BL)and one lepromatous (LL) patient. The bacterial index (BI) for mostindex patients was negative except for the one BL patient with a BIof 4 and the LL patient with a BI of 6. One patient refused to have asmear taken. In the 16 index patients symptoms were detected atan average of 38 months before diagnosis (range 5 to 120 months).The duration of delay was 18 months (range 1 to 264 months) in thegroup of patients registered in 2013. At intake six contacts (otherthan the contacts who were found to have leprosy within 12 weeksafter BCG) of four index cases gave a history of leprosy in the past,but no details were available. One family represented an exceptionto this finding: the father was a smear positive MB case who wasreleased from treatment in 1985 and restarted MB-MDT in 2013,and thus probably was the primary source of infection. One of hissons was the index case at intake of the trial and one of the othersons developed leprosy within 12 weeks after BCG vaccination. Inthis family there were two more family members with a history ofleprosy. The father is included in Table 3 as one of the 3 contactsever found with leprosy.4. DiscussionWe found that 21 out of 5196 (0.40%) healthy contacts of newlydiagnosed leprosy patients in the ongoing BCG intervention trial inBangladesh developed clinical evidence of leprosy within 12 weeksafter receiving BCG. All these 21 contacts presented with PB formsof leprosy (I, TT and BT), with a nearly equal number of males andfemales, and including both children and adults. Nearly half (43%)presented with signs of nerve function impairment and/or Type 1reaction. Among the contacts with leprosy there was a high numberwith MB index cases (56%) and with a long average duration ofsymptoms before diagnosis, possibly indicating that these contactsexperienced a high level of exposure over a long time.The reported prevalence of leprosy in the four districts of northwest Bangladesh in 2013 was 0.74 per 10,000 population and thenew case detection rate 0.84 per 10,000 (source: Rural Health Program). Considering the high prevalence of leprosy in this area, it isnot surprising that there are many people with subclinical leprosy,some of whom may present clinical signs and symptoms for thefirst time after receiving BCG. Since all of these 21 cases were tuberculoid forms of leprosy, the increase of M. leprae-reactive cellularimmunity may result from boosting of cell-mediated immunity byhomologues M. leprae antigens present in BCG. Alternatively, BCGvaccination has been shown to induce epigenetic reprogrammingof innate cells leading to increased cytokine production in responseto related and nonrelated pathogens for up to 3 months after vaccination, a phenomenon called trained immunity [17].Past studies have shown sporadically that BCG may induce clinical expression of leprosy skin lesions in the short term [18,19]. Infact, this phenomenon was discussed as early as 1960, when aneditorial in the International Journal of Leprosy addressed ‘BCGinduced activations’ and referred to two case reports in the Frenchliterature in 1958 [18]. Data from the Karonga Prevention Trialbetween 1986 and 1989 in Malawi indicated that protection againstleprosy is afforded by a repeated BCG vaccination, even during thefirst year after revaccination, but that the case series is too small toconfirm early ‘induction’ of leprosy after BCG [20]. The main reasonfor paucity of information in literature about this issue is that mosttrials only include long-term follow-up, often starting 1 year aftervaccination. Taking into account in particular the data described forBCG vaccination of contacts in Brazil [11], we anticipated a probable increase in new leprosy patients in the first year after BCG,although we had not expected this to occur as early (within 12weeks) after BCG vaccination, as was observed in the current study.Düppre et al. [11] hypothesized that the accelerated manifestationsof tuberculoid leprosy after BCG vaccination found in their study inBrazil, reflected the influence of BCG in catalyzing the existing antimycobacterial immunity in subjects infected with M. leprae beforeor immediately after BCG vaccination. In line with the Brazilianstudy, we also found predominantly tuberculoid forms of leprosy.

1566R.A. Richardus et al. / Vaccine 33 (2015) 1562–1567The incidence rate in the Brazilian study in the first year was higheramong the contacts without a BCG scar than among those with ascar. We found a similar tendency in our study, although the difference was not very large. Finally, among the contacts who developedleprosy soon after BCG, there was a relative high number of contactswith manifestations of Type 1 reaction, which was not described inthe Brazilian study.Live vaccines, in particular BCG, have a nonspecific beneficialeffect on overall mortality when administered early in life, morethan can be explained by the targeted infection [21]. In fact childrenwith a scar or a positive skin test resulting from BCG vaccination,exhibit an overall reduction in child mortality of around 50% [22].In adults, immunization with BCG causes increased levels of proinflammatory cytokines TNF and IL-1 in response to BCG-relatedstimuli that is maintained for up to three months after vaccination [23]. The adaptive immune response after BCG vaccinationis clearly Th1-skewed and results in Mtb- and M. leprae-specific,IFN- producing CD4 T cells that provide an early response tothese mycobacteria and are associated with some degree of protection [24]. However, as is evident from several studies, the IFN- response induced by BCG vaccination does not correlate with protection [25–27]. In addition, Th17 helper cells producing IL-17 andIL-22 are produced as well which are beneficial for protectionagainst pathogens at mucosal sites [28].In 1989, Bagshawe et al. [29] also already hypothesized that prevailing immunity to mycobacterial antigens is largely responsiblefor clinical manifestations of PB leprosy and that the non-specificimmune stimulation induced by BCG vaccination can precipitateclinical signs and symptoms of leprosy in people incubating thedisease and cause upgrading of established lesions, especially inindeterminate or borderline leprosy. In the Karimui trial in PapuaNew Guinea [29], a 47% protection against clinical leprosy by BCGwas demonstrated. However, they provided evidence for accelerated manifestation of tuberculoid leprosy in children vaccinatedwhen under 5 years of age. In our study, children less than 5 yearsold were excluded, but we observed this phenomenon among allother ages.Among the index cases in our study more than half had MB leprosy, with an average duration of symptoms before diagnosis ofover three years, compared with 18 months in all newly registeredleprosy patients in the Rural Health Program in 2013. We also foundthat in the group of 21 contacts that developed leprosy, a higherproportion were blood relative and/or a household contact of theindex patient than in the group of contacts that did not develop leprosy. These factors represents a high level of exposure over a longduration and possibly increased susceptibility for leprosy, but definite conclusions on the relationship between level of exposure andchance of contacts to develop leprosy soon after BCG vaccinationcannot be drawn until the trial is completed and immunologicaland gene expression data are available.Presentation of leprosy as part of an immune reconstitutioninflammatory syndrome (IRIS) in HIV infected individuals or AIDSpatients starting their highly antiretroviral active (HAART) therapyhas been described [30,31]. Previously, Deps et al. [30] proposedthe case definition for IRIS in leprosy as leprosy and/or Type 1reaction and erythema nodosum leprosum (ENL or Type 2 reaction) developing within 6 months after initiation of HAART. Theyfound that 89.5% of the leprosy/IRIS cases presented a histopathological diagnosis of TT or BT leprosy. The mean time until onsetof IRIS after initiating HAART was 8.7 weeks. Fifty-seven percentof the leprosy patients presented within 8–12 weeks after initiating HAART [31]. Two main forms of leprosy as IRIS occurringin the first few months of HAART were identified [30]. The firsttype is an inflammatory ‘unmasking’ of a previously untreated M.leprae infection, the second (less commonly occurring) is a paradoxical clinical deterioration in pre-existing leprosy during which thepatient developed HAART-associated Type 1 reaction. We proposethat a comparable process leads to presentation of clinically apparent leprosy after BCG vaccination of contacts of leprosy patients.In our trial we found an unexpectedly high proportion of newleprosy patients among apparently healthy household contacts ofleprosy patients in the first 12 weeks after receiving BCG vaccination. When all follow-up data of the trial are available, we willcompare PB/MB proportions in new cases arising among contacts atdifferent time points after BCG vaccination and in a group withoutBCG vaccination. If a higher proportion of contacts present withPB leprosy in the first 12 weeks after BCG and later (in the following 1–2 years) a higher proportion of contacts present withMB leprosy, this would support the theory that BCG acceleratesthe immune response and reveals highly immunologically activeforms of subclinical leprosy first. In fact BCG vaccination given tohousehold contacts of leprosy patients could actually identify thisimportant group, who will then receive proper treatment at an earlystage. However this does not imply that BCG should be seen as alegitimate diagnostic test for pre-clinical leprosy. Further investigation including analysis of the cytokine/chemokine range inducedafter BCG vaccination [32], is necessary to understand this phenomenon. Differentiation of the patients through epidemiologicaland immunological studies will be undertaken, in order to carefullyconsider the implications of giving BCG vaccination to contacts ofnewly diagnosed leprosy patients as immunoprophylaxis as part ofa leprosy control programme.Ethical approvalThe national Research Ethics Committee (Bangladesh Medical Research Council) has approved the study protocol (Ref no.BMRC/NREC/2010-2013/1534).Funding statementThis study was supported by the Order of Malta-Grantsfor-Leprosy-Research (MALTALEP), the Q.M. Gastmann-WichersFoundation, and the Netherlands Leprosy Relief Foundation (NLR;ILEP#: 7020273) together with the Turing Foundation.Conflict of interest statementThe authors declare that they have no conflict of interest.AcknowledgementsThe authors gratefully acknowledge all patients and contactsfor participating in this study. Erasmus MC, LUMC and TLMI arepart of the IDEAL (Initiative for Diagnostic and EpidemiologicalAssays for Leprosy) Consortium. The Rural Health Program (RHP)is supported by The Leprosy Mission International (TLMI). We areindebted to the RHP staff for recruitment of study participants andsample collection.References[1] Colditz GA, Brewer TF, Berkey CS, Wilson ME, Burdick E, Fineberg HV, et al.Efficacy of BCG vaccine in the prevention of tuberculosis: meta-analysis of thepublished literature. JAMA 1994;271(9):698–702.[2] Lalor MK, Ben-Smith A, Gorak-Stolinska P, Weir RE, Floyd S, Blitz R, et al. Population differences in immune responses to Bacille Calmette-Guérin vaccinationin infancy. J Infect Dis 2009;199(6):795–800.[3] Lalor MK, Floyd S, Gorak-Stolinska P, Ben-Smith A, Weir RE, Smith SG, et al.BCG vaccination induces different cytokine profiles following infant BCG v

of 21 cases of leprosy (among 5196 vaccinated con-tacts) during this first period after BCG vaccination and describe the characteristics of these patients and their disease symptoms. Furthermore, the possible underlying immunological mechanisms and implications for public health practice are discussed. 2. Methods The