A team of U.S. researchers has create the "most genetically modified animals in existence" in a bid to make viable pig-to-human organ transplants a reality.
Now scientists in a new study have overcome this (fairly huge) obstacle as they have been able to create piglets without any of these viruses present in their system. They report the successful births of several PERV-free piglets, although to date they have survived only to four months.
This could theoretically make "xenotransplantation" (i.e., the transfer of organs from animals to humans) a safe option, especially considering the complementary biology that certain pig organs have with their homo sapien counterparts.
Xenotransplantation is the process of grafting or transplanting organs or tissues between members of different species.
The reason pigs are desirable as possible sources of organs is that their organs are similar to humans in both size and anatomy.
For decades, scientists have been pursuing the idea of pig transplants. "It really is going to be dramatic how it could affect many human lives", he added.
"These are the first Perv-free pigs", Dr Luhan Yang, one of the researchers from Harvard University and the spinout company eGenesis, told the BBC News website. But doctors have used some pig parts - like heart valves or pancreas cells - as replacements in humans before and there was no evidence of infection in those cases.
"We want to create a world where there is no organ shortage", Yang said. Tector says his own team stopped worrying about the viruses years ago, because it is not clear whether the U.S. Food and Drug Administration will require the viruses to be removed prior to transplantation. As a result, Church had wondered if they play an essential role in the pig's survival and whether the animals could develop properly without them. A new global research initiative has another approach: Using CRISPR gene editing on pigs to make them into safe organ donor candidates for humans.
According to the UNOS web site, there were 33,611 organ transplants in 2016 and 116,800 patients on waiting lists. Today 15 of the piglets are alive.
Genetically modified pigs are being engineered to grow human transplant organs, but the existence of Pervs has been a major stumbling block in the development.
After a thorough antivirus scan, de-bugged pigs are a step closer to growing organs for us.
Professor Ian McConnell, an expert in the field from Cambridge University, said the research was a "promising first step". "But the use of animal organs such as pig kidneys and hearts is not without serious ethical and biosecurity concerns".