mRNA vaccine by UPenn scientists could manage bird flu outbreak

Some scientists concerned about bird flu vaccines made using eggs
Process is time-consuming, would take tens of thousands of chickens
mRNA vaccines, like the one from UPenn, don't require eggs

Updated: May 29, 2024 / 05:06 PM CDT

In this photo provided by the Wisconsin Humane Society, two people at the humane society’s Wildlife Rehabilitation Center in Milwaukee provide care to a female bald eagle that later tested positive for the avian influenza, April 8, 2022. The female bird had been captured earlier in the day from a lakeside neighborhood after neighbors noticed it on the ground beneath the nest.(Wisconsin Humane Society via AP)

(NewsNation) — A new experimental mRNA vaccine developed by researchers at University of Pennsylvania’s School of Medicine could help manage the outbreak of the H5N1 virus seen in birds and cattle, and also prevent human infections.

These new findings about the bird flu were published last week in Nature Communications.

“The mRNA technology allows us to be much more agile in developing vaccines; we can start creating a mRNA vaccine within hours of sequencing a new viral strain with pandemic potential,” Scott Hensley a professor of Microbiology at the Perelman School of Medicine, said in a statement.

Hensley and his laboratory collaborated with Drew Weissman, a professor and director of vaccine research at Penn Medicine, and his lab, to conduct this research. Weissman said before 2020, experts had limited options for creating a vaccine. However, the COVID-19 pandemic showed scientists the “power of mRNA-based vaccines as tool to protect humans from emerging viruses quickly,” Weissman said.

“We are better prepared now to respond to a variety of viruses with pandemic potential, including influenza,” he said.

Unlike other influenza inoculations, mRNA vaccines do not require eggs for their development. Scientists, according to KFF Health News, say the current stockpiled formulations against the bird flu virus require two shots, and 90 micrograms of antigen — but still only give people “middling” immunity.

“For the U.S. alone, it would take hens laying 900,000 eggs every single day for nine months,” Bright said in a KFF Health News article published on CBS.

To create egg-based influenza vaccines, experts inject fertilized chicken eggs with what they think will be the dominant viral strain of the disease. Scientists then let the virus replicate, then inactivate it to be used in flu shots distributed around the world. However, this process can take up to six months, which UPenn experts point out could pose problems at a time when vaccines are needed quickly.

“mRNA vaccines are easily and quickly adapted to protect against different strains of influenza viruses, and don’t require eggs for their development,” the University of Pennsylvania said in a news release.

To develop their mRNA vaccine, researchers targeted the subtype of the bird flu virus that is circulating in poultry and cattle. Researchers saw a strong antibody and T-cell response in mice and ferrets who were given the vaccine. Along with that, the animals kept up high levels of antibodies even a year after being vaccinated.

“Researchers found that vaccinated animals who were subsequently infected with H5N1 cleared the virus more rapidly and displayed fewer symptoms than unvaccinated controls,” UPenn said. In addition, all of the vaccinated animals survived their bird flu infection, while those who were unvaccinated died. When the mRNA vaccine was tested with an egg-based one in mice, researchers found they were both equally as effective.

Should humans be concerned about bird flu?

It is “extremely rare” for the bird flu to be spread between humans, according to the Cleveland Clinic. However, humans can be infected if they come in contact with the body fluid of an animal with H5N1, such as “spit, respiratory droplets or feces,” the medical center said. Humans might also breathe in small dust particles in animal habitats, or get it in their eyes, nose or mouth after touching these fluids.

This year, there has only been one confirmed human case of bird flu in Texas. That marked the state’s first case. In that case, the person who got bird flu had direct exposure to dairy cattle presumed to have been infected. Their only symptom had been eye inflammation.

Symptoms of bird flu in humans, according to the Centers for Disease Control, include eye redness; mild flu-like upper respiratory symptoms; pneumonia; high fever; cough; sore throat; runny or stuffy nose; muscle or body aches; headaches; fatigue; and shortness of breath or difficulty breathing. Others that are less common are diarrhea, nausea, vomiting, or seizures, Researchers have not found a definitive reason for the spread of bird flu to cattle. A leading theory by Jenna Guthmiller, an assistant professor of immunology and microbiology at the University of Colorado School of Medicine, is that it has to do with milking machines that could be carrying the virus. High levels of the virus have been found in cows’ udders, Guthmiller said.

NewsNation digital reporter Safia Samee Ali contributed to this report.