Imagine a Covid-19 vaccine in pill form: no needles, no healthcare professionals needed to administer it, potentially delivered straight to people’s homes.
Israeli pharmaceutical company Oramed is trying to achieve this and is preparing to launch its first clinical trial in early August, CEO Nadav Kidron told AFP in an interview.
With only 15% of the world’s population fully vaccinated, the global fight to end the pandemic is far from over.
Oral vaccines are particularly attractive to developing countries because they reduce the logistical burden of vaccination campaigns, Kidron said.
But they could also increase adoption in wealthy countries where aversion to the needle is an often-missed reluctance factor.
A recent survey found that nearly 19 million Americans who refuse vaccines would take them if they had a pill option.
“For the vaccine to work really well, we need as many people as possible to take it,” Kidron said.
Other benefits include reduced syringe and plastic waste and potentially fewer side effects.
– Challenges for oral delivery –
Despite many theoretical advantages, there have been few successful oral vaccines because the active ingredients tend not to survive the journey through the gastrointestinal tract.
Exceptions include vaccines against diseases that are themselves transmitted through the mouth and digestive system – for example, there is an effective oral polio vaccine.
Oramed, which was founded in 2006, believes it has overcome technical hurdles by designing a capsule that survives the highly acidic environment of the gut.
She invented her technology for an earlier product, an experimental form of oral insulin, the life-saving drug required by diabetics that was until now only given by injection.
Developed with Nobel Prize-winning biochemist Avram Hershko who is part of Oramed’s scientific advisory board, the company’s capsule has a highly protective coating that makes it slow to break down.
It also releases molecules called protease inhibitors which prevent enzymes in the small intestine from breaking down insulin, and an absorption enhancer to help insulin pass into the bloodstream.
This drug has been administered to hundreds of patients in advanced clinical trials in the United States, with results expected in September 2022.
Oramed has now launched a new majority-owned company called Oravax, which is taking capsule technology from the oral insulin product and using it for an oral vaccine against Covid-19.
– Virus-like particle –
To evoke an immune response, the company’s scientists designed synthetic coronavirus-like particles.
These mimic three key structures of the pathogen: the spike protein, the coat protein, and the membrane protein.
Most currently licensed vaccines, such as Pfizer or AstraZeneca, are based on the single spike protein, making them less protective over time as the coronavirus spike protein mutates.
By targeting multiple parts of the virus, including structures that mutate less, the Oravax vaccine could be more resistant to variants, Kidron said.
The company has asked to start trials in several countries and plans to start its first trials in Israel in a few weeks, pending approval from the health ministry.
Kidron said he foresees a role for the vaccine initially in developing countries that have not yet purchased enough current vaccines – before eventually expanding the markets.
A vaccine pill might become particularly attractive if continuous boosters are needed.
If this is successful, it would also represent a proof of concept for future oral vaccines, he added.
“Imagine… the flu shot comes to you in the mail, you take it, you’re done. ”
© 2021 AFP