Researchers said “self-disseminating vaccines” could stop coronaviruses passing from animals to humans – but there are concerns of harmful unintended consequences. The unusual proposal could be a cost-effective way to halting deadly pathogens jumping from animal reservoirs and infecting human populations. However there are fears the genetically-engineered viruses could evolve mutations that make them harmful to human and wildlife populations.
In a scientific article entitled ‘Self-disseminating vaccines to suppress zoonoses’, published in Nature magazine, researchers argued the “advances in genetic engineering now raise the possibility of overcoming challenges through the use of self-disseminating vaccines capable of transferring from one individual to the next.”
James J Bull and Scott L Nuismer of the department of Biological Sciences at the University of Idaho argued “it is now more apparent than ever that we need a better and more proactive approach” to halting outbreaks of coronaviruses.
They outline a method of “using vaccines capable of autonomously spreading through wild animal reservoirs” in order to eliminate a potentially harmful disease from affecting human populations.
However, the researchers admit a virus used to transmit a vaccine could evolve back to its original harmful state and thus cause “unintended” consequences.
The researchers stated: “An additional problem confronting attenuated transmissible vaccines is the possibility of evolution returning the vaccine to its wild-type and pathogenic state.”
They added the “sustained replication and transmission” of a self-spreading vaccine “creates substantial opportunities for evolution” where the mutated vaccine could circulate and causes disease.
The researchers point to the escape and circulation of the live polio vaccine as an example of a negative unintended consequence of using this method.
The scientists are “poised to begin developing self-disseminating vaccines to target a wide range of human pathogens” in animals.
This method is also being studied by Dr Michael Jarvis, Plymoth associate professor in virology.
He is heading up efforts to vaccinate animal reservoirs first, ensuring that an outbreak never reaches the human population.
He told the Daily Telegraphy: “With Ebola, once it gets into the human population, now it’s going to be fuelled by human to human transmission.
“For a disseminating vaccine, the horse has already bolted.”
He added: “We’re using the capacity of the vaccine to spread through populations to get high enough coverage in the animal population to prevent the pathogenic virus moving out into the human population.”
The scientists argue it is a cost-effective way to allow a vaccine to “naturally” spread worldwide without the need for developing billions of doses a vaccine to distribute vial injection.
The concept involves re-engineering a “benign virus” by adding genetic material from the coronavirus pathogen and infecting large quantities of reservoir populations.
To get a genetically engineered virus to “self-spread” scientists must first directly inoculate a small population intravenously.
The small population will then go on to spread the virus aerobically.
But, the process of manufacturing a virus to spread a vaccine that protects human health could easily be distorted to develop one that creates a lethal human virus that spreads rapidly around the globe.
Historically this weaponising of the “self-spreading” vaccine technique has already been considered and possibly developed.
South African scientists developed an anti-fertility vaccine to target certain populations during the apartheid era.
The sinister research was codenamed Project Coast.
South Africa’s post-apartheid Truth and Reconciliation Commission was informed by the scientists behind the research the project was in line with the World Health Organization’s attempts to control the global population boom.