Intranasal COVID-19 Vaccine Candidate Shows Potent Immune Responses in Extensive Preclinical Tests
By HospiMedica International staff writers Posted on 15 Oct 2020 |
Illustration
An intranasal COVID-19 vaccine candidate that underwent extensive preclinical testing has shown potent preclinical immune responses, including several that distinguish it from other COVID-19 vaccine approaches.
Altimmune, Inc. (Gaithersburg, MD, USA) is collaborating with the University of Alabama (Birmingham, AL, USA) for clinical trials to evaluate its intranasal dose COVID-19 vaccine candidate, AdCOVID. AdCOVID is based on Altimmune’s adenovirus-based intranasal vaccine platform, and the vaccine candidate expresses the receptor binding domain of the SARS-CoV-2 spike protein. This domain is essential for viral infection, and the majority of neutralizing antibodies found in people who recovered from COVID-19 bind to this receptor binding domain, highlighting it as a target to control infection.
Following partial preclinical results announced in July and August, the latest expanded results show strong activation of both arms of the adaptive immune system following a single intranasal dose of Altimmune’s AdCOVID, as tested at UAB in two strains of mice. The vaccine potently stimulated neutralizing antibodies in the blood plasma that can inactivate SARS-CoV-2 as well as the immune system’s T cells, priming them to attack virus-infected cells. More importantly, the vaccine elicited mucosal antibody and T cell responses in the respiratory tract, including the lung and the nose, creating a possible barrier to infection and transmission at the viral point of entry. The observed IgA response, together with the lung-associated resident memory T cell response, provides an additional level of immune response, as compared to intramuscular vaccination, that may provide enhanced protection against COVID-19 disease and transmission.
Altimmune expects AdCOVID will have an important advantage over some other vaccine candidates that require freezers or ultra-low freezers during distribution. AdCOVID’s expected stability at room temperature would allow distribution without refrigeration, followed by long-term storage in simple refrigerators at clinics or pharmacies. Also, an intranasal inoculation does not require syringes or needles. Additionally, current first-generation COVID-19 vaccines that are given by intramuscular injection, are unable to activate nasal mucosal immunity. Nasal mucosal immunity may be critical for mounting a comprehensive immune response, and it may also prevent further spread of the virus by blocking transmission.
“Intranasal vaccination represents an attractive strategy to prevent COVID-19 infection, as the nasal cavity comprises the first-line of defense against the SARS-CoV-2 virus prior to entry into the lungs,” said Scot Roberts, Ph.D., chief scientific officer for Altimmune. “By stimulating mucosal antibody and T cell immunity, along with potent systemic neutralizing antibody titers, both arms of the immune system can work in concert to prevent and control infection.”
Related Links:
Altimmune, Inc.
University of Alabama
Altimmune, Inc. (Gaithersburg, MD, USA) is collaborating with the University of Alabama (Birmingham, AL, USA) for clinical trials to evaluate its intranasal dose COVID-19 vaccine candidate, AdCOVID. AdCOVID is based on Altimmune’s adenovirus-based intranasal vaccine platform, and the vaccine candidate expresses the receptor binding domain of the SARS-CoV-2 spike protein. This domain is essential for viral infection, and the majority of neutralizing antibodies found in people who recovered from COVID-19 bind to this receptor binding domain, highlighting it as a target to control infection.
Following partial preclinical results announced in July and August, the latest expanded results show strong activation of both arms of the adaptive immune system following a single intranasal dose of Altimmune’s AdCOVID, as tested at UAB in two strains of mice. The vaccine potently stimulated neutralizing antibodies in the blood plasma that can inactivate SARS-CoV-2 as well as the immune system’s T cells, priming them to attack virus-infected cells. More importantly, the vaccine elicited mucosal antibody and T cell responses in the respiratory tract, including the lung and the nose, creating a possible barrier to infection and transmission at the viral point of entry. The observed IgA response, together with the lung-associated resident memory T cell response, provides an additional level of immune response, as compared to intramuscular vaccination, that may provide enhanced protection against COVID-19 disease and transmission.
Altimmune expects AdCOVID will have an important advantage over some other vaccine candidates that require freezers or ultra-low freezers during distribution. AdCOVID’s expected stability at room temperature would allow distribution without refrigeration, followed by long-term storage in simple refrigerators at clinics or pharmacies. Also, an intranasal inoculation does not require syringes or needles. Additionally, current first-generation COVID-19 vaccines that are given by intramuscular injection, are unable to activate nasal mucosal immunity. Nasal mucosal immunity may be critical for mounting a comprehensive immune response, and it may also prevent further spread of the virus by blocking transmission.
“Intranasal vaccination represents an attractive strategy to prevent COVID-19 infection, as the nasal cavity comprises the first-line of defense against the SARS-CoV-2 virus prior to entry into the lungs,” said Scot Roberts, Ph.D., chief scientific officer for Altimmune. “By stimulating mucosal antibody and T cell immunity, along with potent systemic neutralizing antibody titers, both arms of the immune system can work in concert to prevent and control infection.”
Related Links:
Altimmune, Inc.
University of Alabama
Latest COVID-19 News
- Low-Cost System Detects SARS-CoV-2 Virus in Hospital Air Using High-Tech Bubbles
- World's First Inhalable COVID-19 Vaccine Approved in China
- COVID-19 Vaccine Patch Fights SARS-CoV-2 Variants Better than Needles
- Blood Viscosity Testing Can Predict Risk of Death in Hospitalized COVID-19 Patients
- ‘Covid Computer’ Uses AI to Detect COVID-19 from Chest CT Scans
- MRI Lung-Imaging Technique Shows Cause of Long-COVID Symptoms
- Chest CT Scans of COVID-19 Patients Could Help Distinguish Between SARS-CoV-2 Variants
- Specialized MRI Detects Lung Abnormalities in Non-Hospitalized Long COVID Patients
- AI Algorithm Identifies Hospitalized Patients at Highest Risk of Dying From COVID-19
- Sweat Sensor Detects Key Biomarkers That Provide Early Warning of COVID-19 and Flu
- Study Assesses Impact of COVID-19 on Ventilation/Perfusion Scintigraphy
- CT Imaging Study Finds Vaccination Reduces Risk of COVID-19 Associated Pulmonary Embolism
- Third Day in Hospital a ‘Tipping Point’ in Severity of COVID-19 Pneumonia
- Longer Interval Between COVID-19 Vaccines Generates Up to Nine Times as Many Antibodies
- AI Model for Monitoring COVID-19 Predicts Mortality Within First 30 Days of Admission
- AI Predicts COVID Prognosis at Near-Expert Level Based Off CT Scans