Professor Sarah Gilbert, head of the team behind the Oxford AstraZeneca COVID-19 vaccine, has told UK MPs that there is a possibility the vaccine could be taken orally and perhaps also via a nasal spray.
Reported in The Guardian newspaper today, she was asked by MP Graham Stringer how the vaccine might be developed in the future. Gilbert said: “We are also thinking about second generation formulations of vaccine. As you know all the vaccines have been given at the moment as intramuscular injections. That is not necessarily the best way to provide protection against a respiratory virus infection, where we want to the immune system to be active in the upper respiratory tract and then in the lower spiritual tract, which is where the virus is causing the infection.
“And we have flu vaccines that are given by nasal spray. And this could be a very good approach in the future to use vaccines against coronaviruses.
“It’s also possible to consider oral vaccination where you take a tablet that will give you the immunisation, and that would have a lot of benefits for vaccine rollout, if you didn’t have to use the needles and syringes for people.
“Both of those approaches which we are beginning to assess. They will take time to develop. They will have to be tested to safety, and then for efficacy as well because the immune responses that will be generated by both of those approaches will be a little bit different to what we get from an intramuscular injection.
But they have potentially large advantages, and so that’s where we’re going to be focusing our attention on working out if we could use different delivery rates in the future for these vaccines.”
This follows news that iosBio, a UK-based biotechnology company announced an exclusive worldwide licensing agreement with ImmunityBio, a US clinical-stage immunotherapy company, for iosBio’s OraPro vaccine platform technology currently being investigated in trials of ImmunityBio’s second-generation human Adeno (hAd5) COVID-19 vaccine candidate.
OraPro is iosBio’s patented oral delivery vaccine platform technology that enables oral administration of thermally-stable, viral vector vaccines. These vaccine vectors are engineered to withstand temperatures of up to 50°C, allowing them to pass through the hostile conditions in the stomach without loss of efficacy and providing long-term product stability at ambient temperatures. Oral administration delivers the vaccine directly to mucosal associated lymphoid tissue (MALT), generating mucosal, systemic and T-cell immune responses.
Under the terms of the licensing agreement, iosBio has granted ImmunityBio exclusive rights to utilise its OraPro platform technology for the oral delivery of ImmunityBio’s human Adeno (hAd5) COVID-19 vaccine candidate.
In a study of vaccinated non-human primates, subcutaneous and room temperature oral formulations of ImmunityBio’s vaccine candidate inhibited SARS-CoV-2 virus replication to undetectable levels and cleared infection within days in 100% of vaccinated animals (10 of 10). The vaccine candidate, which delivers both outer spike (S) and inner nucleocapsid (N) antigens, induced T cells and antibodies leading to reduction of SARS-CoV-2 viruses in both lungs and nasal passages within seven days. The oral capsule formulation of the vaccine candidate was effective at room temperature in the non-human primate study suggesting that it may not require the cold chain logistics that can impede global distribution.
Pending ImmunityBio’s discussions with the US Food and Drug Administration (FDA), the oral vaccine will enter Phase I trials as a prime and boost and will be explored to provide a boost to subcutaneous vaccinations. Twenty participants have already completed testing in ImmunityBio’s Phase I trial at Hoag Hospital Newport Beach, California, which evaluated both low and high doses of subcutaneous hAd5, with zero grade 3/4 adverse events reported.
Chairman of iosBio, Wayne Channon, said: “We are delighted to be able to support ImmunityBio with the oral delivery of its second-generation COVID-19 vaccine candidate, through the licensing of our OraPro thermal stabilisation technology. This technology is key to developing vaccines that can be administered orally without loss of efficacy and has the potential to truly transform vaccine development.
“Oral vaccines have the potential to overcome global challenges of traditional vaccines, many of which need to be stored and transported at freezing temperatures. Oral vaccines are more cost effective to produce and can be easily stored and transported around the world. They also have the potential to be self-administered, reducing health systems’ dependency on trained health professionals to run immunisation programmes and present a future where people could have vaccines delivered straight to their door.”
Patrick Soon-Shiong, Chairman and CEO of ImmunityBio, said: “As we see multiple mutations in the SARS-CoV-2 spike protein, there is an urgent need for a vaccine that not only offers immediate protection but also activates T cells to clear the virus. When multiple mutations occur at the receptor-binding domain of the spike protein, it renders antibodies ineffective. Our next-generation vaccine design drives both antibody and T cells to S and N protein, and so could potentially serve as a universal boost to current vaccines that focus only on the monovalent S protein, as well as address future mutations of the S protein.
“It is also critical to develop a room-temperature, stable oral formulation of the vaccine, one that will provide mucosal immunity. We’re doing that with iosBio’s unique oral vaccine delivery platform technology that has the potential to transform the way people take vaccines and addresses the challenges of storage and global distribution of vaccines. In our BARDA-sponsored, non-human primate challenge study, administering the oral formulation as a boost achieved 100% viral protection against a challenge and induced both memory B cells and Th1-dominant T cells, which cleared the virus. We are now moving urgently through clinical development in the US and globally.”
Image credit: James Yarema
