Scientists from MedUni Vienna found a vaccine developed at to protect against SARS-CoV-2 indicates that it is effective against all SARS-CoV-2 variants known to date, including omicron—even in those who have not yet built up any immunity as a result of vaccination (non-responders).
The research is published in the journal Allergy and was conducted by Rudolf Valenta et al.
The antigen-based vaccine targets the receptor binding domains (RBD) of the SARS-CoV-2 virus and induced a robust and uniform RBD-specific IgG antibody response in animal models and in human tests.
This antibody response prevents the virus from docking onto and entering the body’s cells, so that infection cannot occur.
The SARS-CoV-2 subunit vaccine (PreS-RBD) is based on a structurally folded fusion protein consisting of two receptor binding domains (RBD) of the SARS-CoV-2 virus and the PreS antigen from hepatitis B, which serve as immunological carriers for each other, thereby strengthening the immune response.
Currently available genetic SARS-CoV-2 vaccines induce mainly transient IgG1 antibody responses, whereas the PreS-RBD vaccine can additionally induce long-lived RBD-specific IgG4 antibodies.
PreS-RBD-specific IgG antibodies detected in blood and mucosal secretions reacted with SARS-CoV-2 variants, including the omicron variant.
Antibodies induced by vaccination with PreS-RBD more potently inhibited the binding of RBD with its human receptor ACE2, and their virus-neutralizing titers were higher than those in a random sample of individuals fully immunized with two vaccinations of currently registered vaccines or than those of COVID-19 convalescents (i.e., individuals who had previously had COVID-19).
The team says the PreS-RBD vaccine has the potential to induce sterilizing immunity to old and new SARS-CoV-2 variants by preventing infection by stopping viral replication and transmission through the inhibition of cellular virus entry.
Moreover, it is expected that the vaccine will even be effective in people who have not previously responded to vaccination (“RBD non-responders”), as they will receive additional T-cell support from the PreS portion of the vaccine.
An earlier study had found that approximately 20% of those recovered from COVID-19 failed to form RBD-specific antibodies and were thus at constant risk of re-infection.
Sign up for our newsletter for more information about this topic.
If you care about COVID, please read studies about new treatment option for COVID-19, and a universal antibody therapy for all COVID-19 variants.
For more information about Covid, please see recent studies that new air filters could rapidly kill COVID-19 and other viruses, and results showing scientists find the cause of persistent breathlessness after COVID-19.
Copyright © 2022 Knowridge Science Report. All rights reserved.
