Self-Disseminating Vaccines and the Fight Against Emerging Infectious Diseases

In the wake of the 2014/2015 Ebola outbreak in West Africa, healthcare professionals are concerned about the world’s ability to handle pandemics and manage emerging infectious diseases. According to a review published in Expert Review of Vaccines, self-disseminating vaccines may be an effective tool at stopping emerging infectious diseases before they start.

Dr. Michael Jarvis, a molecular virologist from Plymouth University School of Biomedical Sciences, and the senior author of the review, is an expert in emerging infectious diseases, and he believes that future pandemics could be prevented by using self-disseminating vaccines to treat zoonotic diseases before they make the jump to infecting humans. The paper was the first of its kind to review self-disseminating vaccines’ potential to prevent the spread of disease.

Emerging infectious diseases represent a growing risk to global human health. Modern agricultural practices, urbanization and widespread long-distance travel are all factors that contribute to the spread of disease – particularly the transmission of a pathogen from an animal population to humans.

Human populations are increasingly encroaching on wildlife territory and as emerging infectious diseases often begin in these groups of animals, the risk of inter-species infection is increasing. Emerging infectious diseases including SARS, Ebola, HIV, and avian flu can all be traced back to an animal-borne infection, and were unknown until they entered the human population.

“In this review we have explored self-disseminating vaccines as an innovative means to prevent EID transmission from animals to humans,” said Jarvis. “From HIV to Ebola and SARS, highly virulent pathogens are continually emerging from animals into the human population.”

According to Jarvis and his colleagues, the challenge in preventing the spread of emerging infectious diseases is to develop vaccines capable of targeting specific high-risk animal populations. This is where self-disseminating vaccines could be useful: these vaccines use viral vectors – specifically cytomegalovirus vectors – that have target specific species, but have a minimal impact on species health.

The vectors carry the vaccine sequence and allow for dissemination of the vaccine across animal populations where it would be difficult to innoculate each individual animal. These vaccines have been used before to inoculate European rabbits against myxomatosis and rabbit haemorrhagic fever. The technique has received renewed interest in the past year since it was identified as a possible method of preventing the spread of Ebola.

“Our review has been based on discussion with scientists from across the conventional and disseminating vaccine fields, and we have used the experience gained through my own and that of my co-author’s experimental work,” said Jarvis. “We suggest that state-of-the-art disseminating vaccines may have a role to play as a new and potentially powerful strategy to circumvent EID at the animal source before their establishment as the next human pandemic.”

Sources:

• Could Self-disseminating Vaccines Cut Off Emerging Infectious Diseases at Source? – http://www.dddmag.com/news/2015/11/could-self-disseminating-vaccines-cut-emerging-infectious-diseases-source