Although the pathology of the respiratory system is the main affectation of the Covid-19 disease, caused by the SARS-CoV-2 coronavirus, many of the patients manifest important neurological symptoms, such as loss of smell (anosmia), headaches, malaise general, cognitive loss, epilepsy, ataxia and encephalopathy, among others. However, this affectation of the nervous system by the coronavirus has not been characterized in detail and it is unknown if the vaccines developed against Covid-19 prevent the spread of SARS-CoV-2 to the central nervous system and confer protection against infections. brain injuries.
Now, using a mouse model susceptible to infection by the SARS-CoV-2 coronavirus, a multidisciplinary team of Spanish researchers led by Javier Villadiego and Juan José Toledo Aral (IBiS, CIBERNED and Department of Medical Physiology and Biophysics of the Faculty of Medicine of Seville) and Juan García Arriaza (Department of Molecular and Cellular Biology of the CNB-CSIC, CIBERINFEC and PTI Global Health of the CSIC), in collaboration with other groups from the University of Seville and the Higher Council for Scientific Research (CSIC), demonstrate the ability of SARS-CoV-2 to infect different regions of the brain and cause brain damage, and how the CNB-CSIC vaccine completely protects against said infection in the brain. These findings are published in the prestigious journal “Nature Neuroscience”.
Researchers have studied the evolution of viral infection in different brain regions, noting that virus replication occurs mainly in neurons, producing neuropathological alterations such as neuronal loss, glial activation, and vascular damage.
Once the pattern of infection in the brain by SARS-CoV-2 was established, the researchers evaluated the efficacy of the vaccine against Covid-19 developed by the CNB-CSIC.
To do this, they immunized mice with one or two doses of the MVA-CoV2-S vaccine, based on the Ankara modified vaccinia virus (MVA) expressing the spike (S) protein of SARS-CoV-2, and analyzed the ability protection against infection and damage to the brain. «The results obtained were spectacular, demonstrating that even the administration of a single dose of the MVA-CoV2-S vaccine completely prevents SARS-CoV-2 infection in all brain regions studied. and prevents associated brain damage, even after reinfection with the virus, which demonstrates the great efficacy and immunogenic power of the vaccine that induces sterilizing immunity in the brain”, as indicated by Juan García Arriaza.
The data we have obtained on SARS-CoV-2 infection in the brain are compatible with the neurological pathology observed in patients with Covid-19.
These results reinforce previous data on the immunogenicity and efficacy of the vaccine. MVA-CoV2-S in various animal models. «We had previously shown in a series of publications that the MVA-CoV2-S vaccine that we developed at the CNB-CSIC induces in three animal models (mouse, hamster and macaque) a powerful immunological response of antibodies binding to the S protein of the virus. and neutralizing antibodies against different variants of the virus of concern, as well as activation of T lymphocytes, essential markers for infection control”, says Mariano Esteban, a CNB-CSIC researcher involved in the study.
The generated results have important long-term implications for understanding the infection caused by SARS-CoV-2. “The data that we have obtained on SARS-CoV-2 infection in the brain are compatible with the neurological pathology observed in patients with Covid-19”, highlights José López Barneo, an IBiS researcher who participated in the publication.
Our work is the first study of a vaccine that is 100% effective against brain damage caused by SARS-CoV-2 in a susceptible mouse.
“Our work is the first study of a vaccine that is 100% effective against brain damage caused by SARS-CoV-2 in a susceptible mouse, and the results obtained strongly suggest that the vaccine could prevent persistent Covid-19. observed in many people infected with SARS-CoV-2”, highlights Juan José Toledo Aral.
“The data provided in this study with complete inhibition of SARS-CoV-2 replication in the brain mediated by the MVA-CoV2-S vaccine, together with previous studies published by the group and collaborators on the immunogenicity and efficacy of the vaccine against different variants of SARS-CoV-2, support the conduct of phase I clinical trials with said vaccine or similar prototypes to assess their safety and immunogenicity,” the study authors stress.