The COVID-19 pandemic has brought vaccines back into the drug development spotlight, and mRNA vaccines are stealing the show with sales of USD 54.4 billion in 2021 alone. Few know that the developers of the mRNA COVID-19 vaccines actually drew upon years of experience attempting to develop cancer vaccines. This approach goes back several decades, and although the field has to date seen limited success, it has nevertheless witnessed a renewed interests in recent years. We examine the latest trends in cancer vaccine development, and where the opportunities lie for the future of the industry.