It is necessary to develop additional COVID-19 vaccines, as different vaccine approaches have their advantages and disadvantages and may work synergistically. Researchers at Karolinska Institutet in Sweden now report that they have developed a prototype vaccine against SARS-CoV-2 using a DNA vaccine platform that is inexpensive, stable, easy to produce, and shows a good safety profile. A study published in Scientific Reports shows that the vaccine induces potent immune responses in mice.