Analysis of three cases of disseminated BCG infection in infants after BCG vaccination in Beijing, China.

We report and analyze three cases of disseminated BCG infection in infants after BCG vaccination that occurred between 2022 and 2024 in Chaoyang District, Beijing, which were the only three monitored during the clinical application we conducted. All the patients had primary immunodeficiency disease (PID). Two cases had defects in the JAK3 and TNFRSF13B genes; one case had multiple gene defects in CR2, IFNAR2, TLR2, and exon 13 of DOCK11. Disseminated BCG infection is a rare adverse reaction after BCG vaccination. It occurs almost exclusively in immunodeficient infants or children. Although it rarely occurs, it is necessary to pay more attention to clinical practice because of its serious consequences.