Vector vaccine. In this type of vaccine, genetic material from the COVID-19 virus is inserted into a different kind of weakened live virus, such as an adenovirus. The weakened virus (viral vector) serves as a delivery system. When the viral vector gets into your cells, it delivers genetic material from the COVID-19 virus that gives your cells instructions to make copies of the S protein. Once your cells display the S proteins on their surfaces, your immune system responds by creating antibodies and defensive white blood cells. If you become infected with the COVID-19 virus, the antibodies will fight the virus.Viral vector vaccines can’t cause you to become infected with the COVID-19 virus or the viral vector virus. Also, the genetic material that’s delivered doesn’t become part of your DNA. The Janssen/Johnson & Johnson COVID-19 vaccine is a vector vaccine. AstraZeneca and the University of Oxford are also working on a vector COVID-19 vaccine.