ABOVE: Colored transmission electron microscopic image of adenovirus virions
CDC /DR. G. WILLIAM GARY, JR.
Six vaccine candidates in clinical trials for COVID-19 employ viruses to deliver genetic cargo that, once inside our cells, instructs them to make SARS-CoV-2 protein. This stimulates an immune response that ideally would protect recipients from future encounters with the actual virus. Three candidates rely on weakened human adenoviruses to deliver the recipe for the spike protein of the pandemic coronavirus, while two use primate adenoviruses and one uses measles virus.
Most viral vaccines are based on attenuated or inactivated viruses. An upside of using vectored vaccines is that they are easy and relatively cheap to make. The adenovirus vector, for example, can be grown up in cells and used for various vaccines. Once you make a viral vector, it is the same for all vaccines, says Florian Krammer, a vaccinologist at the Icahn School of ...
