Since the publication of the Handbook of Experimental Pharmacology Vol. 197 in 2010 there have been important advances in drug development, drug delivery and – more recently – drug targeting. This is in particular relevant with the new generation of drugs acting on the immune system and tumors. These are quite often accompanied by major adverse reactions. Safe therapy is, therefore, an important area of research, in particular in chronic diseases and in persons of old age. In addition, the Covid-19 pandemic has brought renewed attention to vaccinations against viral infections, and mRNA vaccines have been tested for vaccination in tumor therapy, too. Vaccine delivery has stimulated important research on carriers which may pave the way for other applications and enhance a path to e.g. CRISPR-cas therapy.