New approach to creating DNA virus vaccines

A novel approach could accelerate the development of vaccines for DNA-based viruses.

Virus genomes can be composed of DNA or RNA. Both types reproduce by forcing host cells to make copies of the virus' genomes and their encoded proteins. Researchers at Rutgers, the State University of New Jersey, have developed a new way to produce live-attenuated vaccines – weakened viruses to trigger immune responses without causing illness – for DNA viruses. A live virus was treated with a biological compound, centanamycin, which binds to DNA and blocks it from replicating. The result is a virus unable to reproduce or cause further infection.

'We have found this method is safe [in mice]; the attenuated virus infects certain cells without proliferating beyond that and alerts the host to produce specific neutralising antibodies against it,' said Dr Dabbu Jaijyan, a researcher at Rutgers New Jersey Medical School and an author of the study. 'One of the major advantages of our technology is the safety offered by the robust inhibition of the virus replication and that no progeny viruses are produced.'

DNA viruses include cytomegalovirus, herpes simplex 1 and 2, and the virus that causes chicken pox.

Published in Cell Reports Methods, the researchers have discovered that several different vaccines for DNA viruses made this way produced an effective immune response in lab mice and which protected them against infection when subsequently exposed to non-attenuated copies of the same virus. They hope to eventually test their vaccines in humans.

The authors say their method is highly adaptable and should work for any DNA viruses. However, the approach would not be able to make vaccines for viruses whose genomes are composed of RNA, such as SARS-CoV-2, the virus that causes COVID-19.

'Our technology can be easily applied to any DNA virus to generate live-attenuated replication-defective viruses for vaccine development,' said Dr Jaijan. 'We see this as a novel method that we hope will accelerate vaccine development for many untreated viral infections in humans and animals.'