Covid Reithera vaccine, what the first data on phase 2 say

Data on 917 volunteers indicate a good antibody response. Furthermore, the vaccine is well tolerated. But the funds, blocked by the Court of Auditors in May, are still standing

(Photo: Willfried Wende via Pixabay)

The development of new vaccines against Covid-19 does not stop. Today we return to talk about the Italian vaccine from troubled history Grad-Cov, developed by the biotech company Reithera, based in Castel Romano, together withSpallanzani Institute of Rome. The Court of Auditors recently funding blocked for the study of vaccine in phase 3, the last step of the clinical trial (here the reasons). Beyond the economic and bureaucratic aspects of the affair, today however new favorable data arrive on theeffectiveness in generating an immune response and on safety of Reithera in the phase 2, intermediate stage in which tests are still carried out on a small sample of volunteers.

According to the preliminary data disseminated, 3 weeks after the first dose, the researchers found a antibody response (part of the immune response) in 93% of the participants and after the second administration it would reach 99%. These results derive from a preliminary analysis, carried out by Reithera and not yet published, so we will have to wait for the official publication to get all the details. Anyhow the funds are still firm and to date we do not know if and how the experimentation will continue.

The study is in phase 2

Currently the clinical study, called Covitar, has even 917 volunteers inside 24 centers and Italian hospitals distributed throughout the territory. The research is in phase 2, remembering that only later, in phase 3, tens of thousands of participants are generally involved. The researchers compared different vaccination regimens, including one that involved a single administration and another that included a booster. Even the vaccine of Reithera is based on the use of a viral vector, a harmless adenovirus, such as vaccines from AstraZeneca and Johnson & Johnson. This virus carries the information necessary to produce the coronavirus spike protein against which our immune system will activate.

Grad-Cov of Reithera is well tolerated

From the data the safety profile is favorable, and the vaccine turns out well tolerated at the first dose e even more to the second. This is similar to what happens somewhat as with the vaccines of AstraZeneca and Johnson & Johnson, the side effects occur more on the first administration – on the contrary with Pfizer-BioNTech e Modern the recall is associated with multiple reactions (we always talk about mild and moderate effects). The most frequent reactions concern pain at the injection site, fatigue, headache and muscle aches, and there have been no serious adverse events – always remembering that the sample is still small and that more extensive evidence on this aspect will be obtained. only with step 3.

How the immune system is activated

From the first data also theactivation of the immune system the vaccine results good. The Reithera company reports that three weeks after the first dose, one is observed antibody response against the extra spike protein of the coronavirus in 93% of volunteers. It reaches 99% after the second administration. To understand the extent of this immune response, scientists add that after 5 weeks from the first vaccination on antibody level which bind the spike protein and which neutralize the coronavirus is comparable to that measured in a reference group of patients recovering from Covid-19 infection.

Furthermore, the specialists of Reithera point out that there is also an activation of the T lymphocytes. And that it is precisely the action of these cells, as is the case with other vaccines, that it is important to counteract the action of variants such as the delta, in which the spike protein is mutated (and antibodies, which are directed specifically against the spike, are also less efficient).

But there are practical problems

Ma la continuation of clinical trials it could be undermined by financing problems. The funds – 81 million euros – promised by Invitalia never reached the company, stopped by the Court of Auditors. And the Spallanzani institute, which coordinates the tests, has not yet enrolled the new volunteers for the larger study. In conclusion, we will have to wait to understand if the situation of the Reithera Grad-Cov vaccine will unlock or not.

Categories:   Science