- Chickens immunised with the spike protein of SARS-CoV-2 create antibodies that spread to their eggs
- Researchers from Stanford University are currently carrying out tests on humans in Australia
- Should this show positive results, investigators hope to launch an efficacy trial
Creativity, flexibility and plenty of teamwork are what's helping scientists all over the world to search for ways to protect against the new coronavirus.
While some vaccine candidates are showing promising results, the search for protection against Covid-19 carries on. A new trial taking place in Australia is currently testing whether nasal drops containing antibodies to SARS-CoV-2 made by chickens can provide protection to humans.
The researchers from Stanford University say that if the phase I study is successful, we may soon see people like those working in crowded spaces, passengers about to board aeroplanes, and families getting together applying protective nasal drops.
“There is a huge opportunity,” Daria Mochly-Rosen, the leader of the study, told Science Magazine.
Although other protective nasal sprays are currently being tested to see if they can fight the virus, the Stanford study is the first of its kind relying on antibodies harvested from the egg yolks of chickens immunised with the surface protein of the Covid-19 virus.
This study is incorporating unusually low-tech elements. It will assess the safety of the intranasal (through the nose) antibodies and how long they persist in the nose.
Additionally, the team also plans to test whether the drops will protect hamsters after deliberate exposure to the virus.
The placebo-controlled safety trial is currently taking place with 48 human participants.
'The proof is in the pudding,' says study lead
Michael Diamond, an infectious disease clinician at Washington University School of Medicine told Science Magazine that “the concept, in principle, sort of makes sense”, but that there are a few issues to consider.
Diamond is currently developing a nasal-administered vaccine for Covid-19.
One of these issues, he explained, is how long the chicken antibodies will remain active before they begin to deteriorate.
Mochly-Rosen is, however, confident the antibodies will pass the tests, although she acknowledges that “the proof is in the pudding”.
Why chicken antibodies?
The idea for the study came from SPARK’s director, Michael Wallach at the University of Technology Sydney. Wallach has already produced vaccines to protect chickens from disease and has tested chicken antibodies in a mouse influenza (flu) model.
This study also has backing from clinical trials testing whether gargling with IgY (immunoglobulin Y) antibody solutions can protect cystic fibrosis patients from a respiratory tract infection with Pseudomonas aeruginosa – a type of germ that can cause infections in humans, explains the Centers for Disease Control and Prevention (CDC).
Other trials are testing an IgY mouthwash to prevent dental plaque caused by Streptococcus mutans – a bacteria associated with tooth decay – and a food supplement to treat Helicobacter pylori, a common type of bacteria that causes chronic inflammation in the stomach.
The project is part of SPARK, a non-profit launched in 2006 by Mochly-Rosento. It aims to help academics conduct proof-of-concept studies that could translate biomedical research ideas into medicines.
Lab-made antibodies for human medicines are expensive to develop and then manufacture, Science Magazine explains, and often rely on huge numbers of cells grown in bioreactors.
On the other hand, making chicken antibodies is much more cost-effective: researchers inject the spike protein into the chests of chickens, and they then mount an immune response to it.
The eggs that these birds lay will then contain antibodies against the coronavirus protein.
Once this is done, the researchers harvest the antibodies (IgY) from the yolks and formulate the nasal drops.
The cost? A low $1 (R15) for a dose of the product, the team estimates.
If the product is found to be safe, without any serious side effects, SPARK hopes to launch an efficacy trial in the US.
“The number of Covid-19 patients in Australia is zilch, so we have to come back here,” said Mochly-Rosen, who has already started discussions with the US Food and Drug Administration (FDA).
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