Human cases of deadly H5N1 avian flu continue to happen globally, with the latest human cases detected in China — prompting scientists to begin work on a vaccine.
The most recent human cases of avian flu have only been outside of the U.S. Two cases were identified Feb. 24 in Cambodia and now two more have been detected in China. The CDC continues to maintain that at this time the overall risk to the public remains low, but the increasing incidence of infections worldwide has some experts concerned.
"Avian flu is not new; epidemiologists have been studying it for decades," according to the Scientific American. "But the detection of the virus in mammals has many concerned about the potential that it could spill over to humans and cause a larger outbreak."
The H5N1 strain of avian flu is particularly deadly in humans, with a mortality rate of 50 percent according to the CDC, which is why vaccine development could be critical.
The U.S. government is developing an H5N1 vaccine in case they are needed at a large scale and also has a small stockpile of egg-based vaccines for the strain, according to the Scientific American. However, since H5N1 is particularly deadly to poultry, the country also has a protected location of chickens in case further egg-based vaccine development is needed.
The Department of Health and Human Services also has a partnership with CSL Seqirus, one of largest vaccine developers, and has been working on efforts related to avian flu since 2010. A member of CSL's pandemic preparedness and response team told Scientific American if needed, it "would be able to supply the U.S. government with 150 million doses within the first six months of a pandemic being declared, but … the scale-up potential could be higher, especially if multiple manufacturers could help produce it."
Other efforts are also being made to look into mRNA vaccine development for H5N1, the Scientific American reported.