Swine Flu Spread Helps Scientists Understand Avian Flu Potential

Kathleen Blanchard's picture

Swine flu spread has led researchers to a better understanding of how viruses mutate and spread among humans. A University of Maryland study recently looked at the underlying mechanism of avian-human virus spread, finding that avian flu potential may be greater than previously thought.

The research, led by Professor Daniel Perez from the University of Maryland, found that once a virus mutates to combine with human virus, it could rapidly spread between mammals through respiratory droplets. Watching the current spread of swine flu shows the scientists that avian flu has the same potential for spread among humans.

"The virus formed when avian, swine, and human-like viruses combined in a pig to make a new virus. After mutating to be able to spread by respiratory droplets and infect humans, it is now spreading between humans by sneezing and coughing”, says Perez.

Because avian viruses normally affect birds, and human viruses affect humans, immunity is present because the immune system recognizes the virus. When avian flu virus and human flu virus combine, the immune system is defenseless.

Perez focused on the avian H9N2 influenza virus for his study, because of avian flu potential for pandemic, creating a genetically engineered hybrid human-avian virus. They used a virus different, though similar to the current swine flu virus, now known as the H1N1 virus, produced from a different strain of virus.


Ferrets were infected with the flu virus, and allowed to mutate. Within a short time, ferrets who only shared the same air space become infected, showing that the mutated avian-human virus spread through respiratory droplets, after undergoing minor mutation. The scientists concluded that an avian flu pandemic could result with just a few mutations of the avian flu virus.

Perez says, “We do not know if the mutations we saw in the lab are the same that have made the H1N1 swine flu transmissible by respiratory droplets. We will be doing more research on the current swine flu strain to study its specific genetic mutations."

The goal of studies such as these is to find ways to produce vaccines to protect from virus mutations such as the swine flu and from mutations that could provoke avian flu pandemic.

Dr. Perez explains, "Many more studies have to be done to see which combinations of mutations cause this type of transmission before we can design the appropriate vaccines." Since no one knows how influenza viruses will ultimately mutate in nature, developing vaccines can be tricky.

Swine flu spread is helping researchers better understand the potential for spread of the avian flu virus, which has been the focus of much research already. Dr. Perez is working with CDC and NIH to find a swine flu vaccine and in developing more research to understand the spread of viruses between animals and humans.