• Known allergy to (components of), or any other contraindication to, the BCG vaccine, MMR vaccine, or alendronic acid.• Known (history of) active or latent Mycobacterium tuberculosis or with another mycobacterial species,• Prior BCG vaccination,• Acute illness 2 weeks prior to the study or (suspicion of) active infection,• Pregnancy,• Chronic use of any systemic drugs other than oral contraceptives,• Use of NSAIDs less than 4 weeks prior to start of the study,• Vaccination in the past 3 months or expected vaccination during the study period, independent of the type of vaccination,• Medical history associated with immunodeficiency.

• Known allergy to (components of), or any other contraindication to, the BCG vaccine, MMR vaccine, or alendronic acid.• Known (history of) active or latent Mycobacterium tuberculosis or with another mycobacterial species,• Prior BCG vaccination,• Acute illness 2 weeks prior to the study or (suspicion of) active infection,• Pregnancy,• Chronic use of any systemic drugs other than oral contraceptives,• Use of NSAIDs less than 4 weeks prior to start of the study,• Vaccination in the past 3 months or expected vaccination during the study period, independent of the type of vaccination,• Medical history associated with immunodeficiency.