The American insurance system is not set up to handle multiple (unnecessary!) visits for vaccines that are now given at the same time. The schedules of American pediatricians and public health clinics are not set up to handle this. The schedules of American parents are not set up to handle this.
Trump: "Effective immediately, my administration is recognizing gold standard childhood vaccine recommendations for only 11 core vaccinations against the most serious and dangerous diseases along with the MMR, which hopefully will be split up."