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Complete protection against severe acute respiratory syndrome coronavirus-mediated lethal respiratory disease in aged mice by immunization with a mouse-adapted virus lacking E protein
Journal article   Open access   Peer reviewed

Complete protection against severe acute respiratory syndrome coronavirus-mediated lethal respiratory disease in aged mice by immunization with a mouse-adapted virus lacking E protein

Craig Fett, Marta L DeDiego, Jose A Regla-Nava, Luis Enjuanes and Stanley Perlman
Journal of virology, Vol.87(12), pp.6551-6559
06/2013
DOI: 10.1128/JVI.00087-13
PMCID: PMC3676143
PMID: 23576515
url
https://europepmc.org/articles/pmc3676143View
Published (Version of record) Open Access

Abstract

Zoonotic coronaviruses, including the one that caused severe acute respiratory syndrome (SARS), cause significant morbidity and mortality in humans. No specific therapy for any human coronavirus is available, making vaccine development critical for protection against these viruses. We previously showed that recombinant SARS coronavirus (SARS-CoV) (Urbani strain based) lacking envelope (E) protein expression (rU-ΔE) provided good but not perfect protection in young mice against challenge with virulent mouse-adapted SARS-CoV (MA15). To improve vaccine efficacy, we developed a second set of E-deleted vaccine candidates on an MA15 background (rMA15-ΔE). rMA15-ΔE is safe, causing no disease in 6-week-, 12-month-, or 18-month-old BALB/c mice. Immunization with this virus completely protected mice of three ages from lethal disease and effected more-rapid virus clearance. Compared to rU-ΔE, rMA15-ΔE immunization resulted in significantly greater neutralizing antibody and SARS-CoV-specific CD4 and CD8 T cell responses. After challenge, inflammatory cell infiltration, edema, and lung destruction were decreased in the lungs of rMA15-ΔE-immunized mice compared to those in rU-ΔE-immunized 12-month-old mice. Collectively, these results show that immunization with a species-adapted attenuated coronavirus lacking E protein expression is safe and provides optimal immunogenicity and long-term protection against challenge with lethal virus. This approach will be generally useful for development of vaccines protective against human coronaviruses as well as against coronaviruses that cause disease in domestic and companion animals.
SARS Virus - immunology Severe Acute Respiratory Syndrome - virology Humans Vaccination Viral Vaccines - genetics Severe Acute Respiratory Syndrome - immunology Viral Vaccines - adverse effects Antibodies, Viral - blood Viral Load CD4-Positive T-Lymphocytes - immunology Antibodies, Neutralizing - immunology Lung - virology SARS Virus - genetics Gene Deletion Disease Models, Animal Immunization Lung - pathology Viral Envelope Proteins - genetics Severe Acute Respiratory Syndrome - mortality SARS Virus - pathogenicity Viral Vaccines - administration & dosage Severe Acute Respiratory Syndrome - prevention & control Animals Survival Analysis Antibodies, Viral - immunology Mice Mice, Inbred BALB C CD8-Positive T-Lymphocytes - immunology Viral Vaccines - immunology Antibodies, Neutralizing - blood

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