Dendritic Cell Vaccines Against Her2/Her3 and Pembrolizumab for the Treatment of Brain Metastasis From Triple Negative Breast Cancer or HER2+ Breast Cancer

Inclusion Criteria: * female participant is eligible to participate if she is not pregnant,not breastfeeding, and at least one of the following conditions applies: * Not a woman of childbearing potential (WOCBP) * A WOCBP who agrees to follow contraceptive guidance * WOCBP must agree to use acceptable birth control methods for the duration of the study and until persistence of the study drug is no longer detected in the peripheral blood:this may be a period of several years. Methods for acceptable birth control include: condoms, diaphragm or cervical cap with spermicide, intrauterine device, and hormonal contraception; it is recommended that a combination of two methods be used. NOTE: If the risk of conception exists, patients must agree to use highly effective contraception throughout the study and for at least two years following the last study treatment administration * Negative serum and highly sensitive urine pregnancy test(s): * At initial screening prior to eligibility confirmation * within 72 hours prior to leukapheresis if \>72 hours have passed between screening test and the Leukapheresis visit * Pregnancy testing will be performed for WOCBP and interpreted prior to every cycle of pembrolizumab (Initial Treatment Phase); * at the End of Treatment (EOT) Assessment; and * whenever pregnancy is otherwise suspected. Note: In the event that 72 hours have elapsed between the screening pregnancy test and leukapheresis, another pregnancy test must be performed and mus…