Scientists have shown in a lab how bird flu could change in three simple mutations and become capable of spreading from human to human.
But fear not, you can put away your Hazmat suit for now – the researchers did not alter the whole virus itself (we’ve all seen enough disaster movies to avoid that blunder). Their incredible research will also help scientists keep one step ahead of the virus to prevent potential spread.
The researchers are interested in a strain called Avian influenza A(H7N9). This virus has infected over 900 people since 2013, according to the World Health Organization. However, the vast majority of these cases have been with people who work within the poultry industry and the virus is not capable of spreading sustainably among humans yet.
In a worse case scenario, the virus could mutate into a form that could do this and potential spread like wildfire. So, scientists from the Scripps Research Institute in California have been playing around with different mutations of the H7N9’s genome to see what would make the virus capable of jumping from human to human. Their study was recently published in the journal PLOS Pathogens.
They specifically looked at a protein on the flu virus surface called H7 hemagglutinin that allows the virus to bind to host cells and infect them. They discovered it takes small mutations in three amino acids found on the flu virus surface to allow the virus to become better at binding to cell receptors found on human cells, compared to those on bird cells.
In the lab, they produced these triple-mutant H7 hemagglutinins and showed they can successfully latch onto cells in samples of human trachea tissue.
Safety regulations prohibit introducing these mutations to actual H7N9 viruses, so the study authors stress they did not create any viruses, they simply used a benign fragment of the virus. The mutations to an actual H7N9 virus background would represent gain-of-function experiments that are currently banned (for understandable reasons).
Still, should we be frightened by these findings? Not yet, it seems. Fiona Culley, an expert in respiratory immunology at Imperial College London, told Reuters that the chances of all three of these mutations occurring together are “relatively low.”
"This study will help us to monitor the risk posed by bird flu in a more informed way, and increasing our knowledge of which changes in bird flu viruses could be potentially dangerous will be very useful in surveillance," she said.