CD4 and infection: For example, when infected with 150–200 CFUs of Mtb H37Rv, VPM1002 showed protection equal to that of BCG Danish in reducing Mtb loads in the lungs at 30 days post-infection, while it was more protective than BCG after 60 days post-infection in C57BL/6 mice, an effect associated with central memory CD4+ T cells37.