Resume: A new vaccine against COVID-19 developed by CNB-CSIC researchers appears to protect against brain infection and neurological symptoms associated with coronavirus.
Font: Sevilla University
Although the pathology of the respiratory system is the main impact of COVID-19, many patients also manifest important neurological symptoms, such as loss of smell (anosmia), headaches, malaise, cognitive loss, epilepsy, ataxia and encephalopathy, among others. others.
However, this effect on the nervous system by the coronavirus has not been characterized in detail and it is unknown whether the vaccines developed against COVID-19 prevent the spread of SARS-CoV-2 to the central nervous system and confer protection against brain damage. .
Now, using a mouse model susceptible to SARS-CoV-2 coronavirus infection, a multidisciplinary team of Spanish researchers led by Dr. Javier Villadiego and Dr. 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 Superior Council de Investigaciones Científicas (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 fully protects against brain infection.
These findings are published in neuroscience of nature.
Researchers have studied the evolution of viral infection in different regions of the brain, noting that viral replication occurs mainly in neurons, producing neuropathological alterations such as neuronal loss, glial activation, and vascular damage.
“We have carried out a very detailed pathological and molecular study of the brain regions and cell types that have been infected by the virus. It is striking how the virus infects different areas and mainly neurons”, explains Javier Villadiego.
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 at the CNB-CSIC. To do this, they immunized mice with one or two doses of the MVA-CoV2-S vaccine, based on the modified vaccinia virus Ankara (MVA) that expresses the spike (S) protein of SARS-CoV-2, and analyzed the ability to protect 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 a reinfection with the virus. This demonstrates the great efficacy and immunogenic power of the vaccine that induces sterilizing immunity in the brain”, affirms Juan García-Arriaza.
These results reinforce previous data on the immunogenicity and efficacy of the MVA-CoV2-S vaccine in various animal models.
“We had already 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 immune response of antibodies that bind to the S protein of of the virus and of neutralizing antibodies against different worrisome variants of the virus, as well as the activation of T lymphocytes, essential markers for infection control”, says Mariano Esteban, a CNB-CSIC researcher involved in the study.
The results have important long-term implications for understanding SARS-CoV-2 infection. “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,” says 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, and the results obtained strongly suggest that the vaccine could prevent persistent COVID-19 observed in several infected people. with SARS-CoV-2”, says 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, they support phase I clinical trials with a vaccine of this type, or similar prototypes, to evaluate its safety and immunogenicity”, emphasize the study authors.
About this COVID-19 research news
Author: press office
Font: Sevilla University
Contact: Press Office – University of Seville
Picture: The image is in the public domain.
original research: Open access.
“Total protection against SARS-CoV-2 infection and brain damage in susceptible transgenic mice conferred by the MVA-CoV2-S vaccine candidate” by Javier Villadiego et al. neuroscience of nature
Full protection against SARS-CoV-2 infection and brain damage in susceptible transgenic mice conferred by the MVA-CoV2-S vaccine candidate
Vaccines against SARS-CoV-2 have been shown to be safe and effective, but their protective efficacy against infection in the brain remains unclear.
Here, in the K18-hACE2 transgenic mouse model susceptible to severe coronavirus disease 2019 (COVID-19), we report a spatiotemporal description of SARS-CoV-2 infection and replication across the brain. Brain replication of SARS-CoV-2 occurs primarily in neurons, leading to neuronal loss, signs of glial activation, and vascular damage in SARS-CoV-2-infected mice.
One or two doses of a modified vaccinia virus Ankara (MVA) vector expressing the SARS-CoV-2 spike (S) protein (MVA-CoV2-S) conferred full protection against SARS-CoV-2 brain infection, preventing the replication of the virus in all areas of the brain and its associated damage. This protection was maintained even after reinfection by SARS-CoV-2.
These findings further support the use of MVA-CoV2-S as a promising vaccine candidate against SARS-CoV-2/COVID-19.
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