An Israeli biotech company developed An oral vaccine that is easier to administer and more effective against most potential future variants. Such a vaccine could speed up the vaccination campaign in emerging countries and thus help the fight against the coronavirus epidemic.
Twenty-four unvaccinated volunteers are testing a pill that is supposed to help immunize against Covid-19, half of them with one dose and the other half with two doses, reports the Jerusalem Post; there is no placebo group since in the first clinical phase only the safety and the level of antibodies generated by the vaccine will be tested.
“If we can vaccinate people with a simple pill, it will revolutionize the whole world,” says Nadav Kidron, head of Israeli biotech company Oramed Pharmaceuticals, which co-founded Oravax with Indian start-up Premas Biotech.
Indeed, injectable vaccines require a lot of logistics and medical personnel, which are not always available in developing countries. This is even more true for messenger RNA vaccines, which must be stored at very low temperatures. “Ease of vaccination is a key factor in accelerating the vaccination campaign worldwide,” says Nadav Kidron. In addition, oral vaccines generally have fewer side effects.
The vaccine, of which several thousand capsules have already been produced in Europe for this study, is based on three structural proteins of the SARS-CoV-2 virus, unlike all current vaccines that target only the spike protein. As a result, “our vaccine should be much more sensitive to future mutations in the virus,” says Nadav Kidron. If the variant manages to bypass the first line of defense, a second and then the third line of defense follows. This principle is being tested by several other start-ups working on a universal vaccine against the coronavirus.
OraVax Medical has already conducted a number of animal trials and has shown that the vaccine generates IgG and IgA antibodies against SARS-CoV-2 that are effective even against the Delta variant. If the trials are successful, the new vaccine will be targeted in particular at emerging countries where vaccination coverage is still low and where there are fewer resources available to vaccinate with conventional vaccines.
The Israeli biotech company is far from alone in this niche. The start-up Rapid Dose Therapeutics and a team from McMaster University (Canada) are also working on a vaccine in the form of a dissolvable oral strip. These strips, infused with the proteins of the virus, can be stored for several months at temperatures up to 40°C. Development is still in the early stages, but animal tests are again encouraging. The start-up company believes that this type of vaccine can be used as a booster.
While there are already a number of oral vaccines on the market, including against cholera, influenza, and polio, it is not certain that they are equally effective against SARS-CoV-2. “Although the gut is considered an important entry site for the virus, the immune response in the blood of Covid-19 patients is dominated by lymphocytes, which are mainly activated by other parts of the body and organs,” explains Sebastian Zundler, a researcher at the University of Erlangen in Germany and co-author of a study published in April in the journal Frontiers in Immunology. Moreover, immune cells induced by the gut are very “dilute” compared to those produced by the lungs. It will therefore be particularly interesting to follow the results of a “real” clinical trial in Israel.