Could snorting chicken antibodies be the next weapon against Covid-19? It sounds unlikely, but a new clinical trial is hoping to find out.
Investigations into the use of an antibody nasal spray to temporarily protect people from SARS-CoV-2, the virus that causes Covid-19, in high-risk situations have begun. The idea is that people could have a quick spray up the nose before they enter a hospital, for example, and line their nasal cavity with protective antibodies. While they remain in this risky environment, they will briefly be protected from Covid-19.
In a phase I clinical trial, scientists at Stanford University and Perth's Linear Clinical Research are investigating a protective nasal spray using antibodies taken from egg yolks of chickens. As detailed on the SPARK at Stanford website, the chickens are infected with the spike protein of SAR-CoV-2, causing them to mount a huge immune response and the production of chicken-specific antibodies, known as immunoglobulin Y (IgY). A fair number of antibodies find their way into the eggs, which the researchers then harvest and integrate into the nasal spray or nasal drops. In theory, the antibodies should block the virus spike protein and prevent the pathogen from invading cells.
“The immunity agent we are testing is not a traditional vaccine, which works by stimulating a person’s immune system to permanently recognize and fight a virus by producing its own antibodies against it. Instead, the nasal drops provide protection by capturing and neutralizing the coronavirus that causes Covid-19 before it enters the body,” Daria Mochly-Rosen, PhD, founder of SPARK at Stanford and a professor of chemical and systems biology at Stanford University School of Medicine, said in a statement.
To test out how effective this method is, the chicken antibody nasal spray is being used in a placebo-controlled safety trial involving 48 people in Australia. The trial is expected to be completed in December 2020 and, if all goes well, the treatment could be available early next year.
The nasal spray would only temporarily guard against the virus and it’s still unknown how long its protection may last, so this is only being considered as a short-term solution. Nevertheless, the researchers are optimistic that it could provide a low-cost way to keep vulnerable people safe during the Covid-19 pandemic until a vaccine is developed. The team estimates the cost of a dose of the chicken-derived antibodies would only be $1.
“The nasal drops will not replace vaccines and measures such as wearing face masks, social distancing, and washing hands,” said Dr Mochly-Rosen. “But they could play a vital role in keeping people safe while the medical community and governments around the world pursue all options for ending the pandemic.”
This isn't the only project exploring the idea of a nasal antiviral spray. An ongoing investigation using ferrets recently blocked the transmission of SARS-CoV-2 using a nasal spray laced with a lipopeptide that binds to virus spike and blocks it from binding with cells. Ferrets are often used in respiratory disease studies because the lungs of ferrets and humans are similar, and ferrets are highly susceptible to SARS-CoV-2, passing it on easily.
In a preprint paper, which is yet to be peer-reviewed, the researchers from Columbia University Vagelos College of Physicians and Surgeons found that all the ferrets that received the spray did not catch the disease from their virus-shedding cagemates. They also didn't notice any negative side-effects to the spray among the ferrets, which bodes well for human trials.