Severe adverse reactions after vaccination with Japanese BCG vaccine: a review

Abstract

Japanese BCG vaccine has been admitted by the quality control of World Health Organization (WHO) as the safest BCG vaccine in the world. Even though, BCG, as a live bacterial vaccine, inevitably causes dissemination beyond vaccination site and regional lymph-nodes to various part of the body under certain special conditions. We tried to review the clinical features and immunological status of the cases in which "severe" adverse reactions had developed after vaccination with Japanese freeze-dried BCG vaccine prepared from BCG substrain Tokyo. "Severe" adverse reaction was arbitrarily defined as the adverse reactions of clinical significance developed beyond vaccination site and regional ipsilateral axillary lymph-nodes. By the extensive search of the literatures, 39 cases were identified since 1951 when vaccination with freeze-dried BCG vaccine became compulsory by the Tuberculosis Prevention Law in Japan. Incidence rate was calculated as 0.0182 cases per 100,000 vaccinations. Clinical manifestations of bone and joint were reported in 27 cases (multiple sites: 15 cases, single site: 12 cases), abnormalities in chest X-ray in 13 cases, skin manifestations in 17 cases, diseases in other sites or organs in 8 cases. Most of the cases had lesions in multiple organs. Among these 39 cases, 13 had been diagnosed to have some types of primary immunodeficiency (5 cases: chronic granulomatous disease (CGD); 4 cases: severe combined immunodeficiency (SCID); 4 cases: IFN-gamma receptor 1 deficiency). Further, unidentified defects in cellular immunity were reported in other 6 cases. Death was reported in 6 cases, but in two cases the causes of death were the infections due to different pathogens, namely, pulmonary abscess due to Staphylococcus sp. and bacteremia due to Pseudomonas aeruginosa, respectively, and in only one case death was evidenced as due to disseminated BCG infection by autopsy. All of 6 death cases had some type of immunodeficiency. Apart from fatal cases, outcome of "severe" adverse events were generally favorable and they were successfully treated by anti-tuberculosis therapy with or without surgical treatment for bone and joint lesions. Because the risk of "severe" adverse reactions is high among those of primary immunodeficiency, so it is advisable to avoid BCG vaccination during the first three months after birth when the detection of immunodeficiency is practically impossible.