Recent advances in synthetic biology have opened up the possibility of finely engineering viral genomes with the goal to understand and prevent viral diseases [1]. Vesicular stomatitis virus (VSV) is one of the most promising viruses for engineering vaccines and oncolytic therapies [2]. Its genome is able to accept large foreign sequences (Figure 1). VSV also remains viable as a pseudotyped virus (an enveloped virus expressing foreign glycoproteins in place of the native surface proteins) [3]. The broad tissue tropism allows for many different routes of administration, such as nasal sprays or intramuscular injection.