A team of scientists in China created hybrid flu viruses by mixing genes from H5N1, an avian influenza, with the H1N1 strain behind the swine flu pandemic of 2009.
The results, published in Science, showed what could happen if the two viruses were to combine. The scientists showed that some of the virus hybrids were able to spread through the air between guinea pigs.
There is no evidence that the swine and bird flu strains have mixed on their own, though it has not been for lack of opportunity. Their geographic ranges have overlapped, along with the species they infect — humans. So far, the H5N1 has mainly swapped genes in its own lineage. However, the H1N1 strain has been known to change easily.
Hualan Chen, a virologist at the Harbin Veterinary Research Institute of the Chinese Academy of Sciences and the study’s leader, explained of the results, “If these mammalian-transmissible H5N1 viruses are generated in nature, a pandemic will be highly likely.”
Chen’s results of a hybrid flu strain will likely reignite the controversy the flu community experienced in 2012 when two groups found that the H5N1 virus could go airborne if it contained specific mutations. Following the debate, the community decided on a moratorium on research that could produce more transmissible strains for one year.
But Chen’s research was completed before the moratorium went into effect. More experiments like his are possible, because the ban has run its course. Jeremy Farrar, director of the Oxford University Clinical Research Unit in Ho Chi Minh City, Vietnam, stated:
“I do believe such research is critical to our understanding of influenza. But such work, anywhere in the world, needs to be tightly regulated and conducted in the most secure facilities, which are registered and certified to a common international standard.”
Chen’s team mixed and matched up every combination of the H5N1 and H1N1 flu viruses to created 127 reassortant viruses. Some of the hybrids were able to spread to guinea pigs in adjacent cages. Those viruses contained the genes PA and NS from H1N1. Two additional genes from H1N1, NA and M, also promoted airborne transmission, though not as much.
The information shows that, should the two viruses combine in nature, they could spread at a much more rapid rate than any previous bird flu or swine flu viruses seen in humans.
[Image via ShutterStock]