This was reported by scientists at the annual meeting of the American Association for Cancer Research (AACR) in New Orleans. The extent to which the 14 patients in the study were actually protected against infection or severe symptoms through vaccination was not examined.
Why previous Covid vaccines only work to a limited extent in cancer patients
Current corona vaccines mainly trigger a so-called humoral immune response in the body, i.e. the formation of antibodies by B cells. However, many chemotherapies and some immunotherapies destroy B cells, so vaccines do not work well in these patients.
Antibody formation is also impaired in people with certain congenital immune defects. CoVac-1 should therefore primarily develop T-cell-triggered cellular immunity. -19 even in the absence of neutralizing antibodies”, explains Claudia Tandler of the University of Tübingen on the occasion. of the presentation of the Results.
These refer to the vaccinations of 14 patients with abnormal B cells, including twelve patients with leukemia or cancer of the lymph nodes. About two-thirds of the patients had already been vaccinated with an approved corona vaccine, but their immune system had not developed a sufficient antibody response. 28 days after CoVac-1 vaccination, researchers recorded a robust T-cell response in 13 patients. A clinical study with more patients is being prepared.
How the new Covid-19 vaccine works
The preparation of the Tübingen researchers is a so-called peptide vaccine. This contains six different protein components (peptides) of Sars-CoV-2 as antigens against which the immune system mounts a T cell response after vaccination. Among them is the spike protein, against which previously available vaccines are also directed. The combination of several viral proteins in a vaccine aims to trigger the broadest possible T-cell immune response, so that the protective effect is retained even in the event of virus mutations.
“As far as we know, CoVac-1 is currently the only peptide-based vaccine candidate developed and evaluated specifically for immunocompromised people,” says Juliane Walz of Tübingen University Hospital, Head of Vaccine Development. It is hoped that this will protect high-risk patients from a severe course of Covid 19.
Researchers around the world are searching for a ‘super vaccine’
In addition, various researches are underway around the world to try to develop a second generation of corona vaccines. For even better effectiveness and protection against infection, they should no longer focus only on the spike protein of the virus, but as few variable areas of the virus as possible.
For example, before the end of this year, the American company ImmunityBio wants to launch a second-generation Covid-19 vaccine that develops an immune reaction against the spike protein and the so-called nucleocapsid. The nucleocapsid is a protein involved in the packaging of the viral genome and less susceptible to change.
Peter Kremsner considers this approach to be theoretically the best option. However, it is still unclear if the development will be successful. “The desire for a universal vaccine is certainly justified, but it is not easy to implement”, explains the director of the Institute of Tropical Medicine at the University of Tübingen.
Development “still in its infancy”
Ideally, vaccines that treat the conserved – i.e. the less changing – areas of the virus not only protect against different variants of a corona virus, but also against different corona viruses such as the corona virus Sars or the virus related Mers corona.
The research approach is fundamentally correct, says Peggy Riese of the Helmholtz Center. “But it has to be said very clearly that we are still in the early stages of developing universal vaccines.” Much basic information about the virus, its spread in nature or its interactions with human cells was still missing.
Other users currently find this video interesting: