Trial Outcomes & Findings for A Ph 2 Trial With an Oral Tableted COVID-19 Vaccine (NCT NCT05067933)

A total of 66 participants were enrolled at 5 sites in the United States between 22 October 2021 and 09 May 2023 (follow-up period cut-off) in Part 1 of the study. Vaxart decided not to conduct Part 2 of this study, so results for Part 2 were not included in this summary.

A Ph 2 Trial With an Oral Tableted COVID-19 Vaccine

Solicited symptoms of reactogenicity were predefined systemic signs and symptoms of reactogenicity for which the participant was specifically questioned, and which were noted by the participant in their daily Solicited Symptom Diary for 7 days after each vaccination, including: * fever (any temperature 100°F or higher) * headache * myalgia (muscle pain) * abdominal pain * anorexia (defined and not eating) * nausea * vomiting * diarrhea * malaise/fatigue

Solicited symptoms of reactogenicity were predefined systemic signs and symptoms of reactogenicity for which the participant was specifically questioned, and which were noted by the participant in their daily Solicited Symptom Diary for 7 days after each vaccination, including: * fever (any temperature 100°F or higher) * headache * myalgia (muscle pain) * abdominal pain * anorexia (defined and not eating) * nausea * vomiting * diarrhea * malaise/fatigue Participants were instructed to rate solicited symptoms of reactogenicity that were collected in their Solicited Symptom Diary with the below grades, against pre-defined criteria as noted in the protocol: * Grade 1 - Mild * Grade 2 - Moderate * Grade 3 - Severe * Grade 4 - Life Threatening Participants with multiple solicited symptoms were only counted once, the highest severity of which was used.

A TEAE was any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention, occurring after first dose of study drug. A serious TEAE was any TEAE that met any of the following criteria: * Resulted in death. * Was life-threatening. * Required inpatient hospitalization or prolongation of existing hospitalization. * Resulted in persistent or significant disability/incapacity. * Was a congenital anomaly/birth defect. * Was a suspected transmission of any infectious agent via a medicinal product. * Was a significant medical event, as judged by the investigator.

All unsolicited TEAEs during the active treatment period were assessed by the investigator using the below scale: * Mild: Events that required minimal or no treatment and did not interfere with the participant's daily activities. * Moderate: Events that resulted in a low level of inconvenience or concern with the therapeutic measures. Moderate events may have caused some interference with functioning. * Severe: Events that interrupted a participant's usual daily activity and may have required systemic drug therapy or other treatment. Severe events were usually incapacitating. * Life Threatening: Any adverse drug experience that placed the participant, in the view of the investigator, at immediate risk of death from the reaction as it occurred. Participants with multiple TEAEs during the active treatment period were only counted once, the highest severity of which was used.

MAAEs were defined as TEAEs with medically-attended visits including hospital, emergency room, urgent care clinic, or other visits to or from medical personnel for any reason. Routine study visits were not considered medically-attended visits. New onset of chronic illness/diseases (NOCI) and adverse events of special interest (AESIs) were collected as part of the MAAEs. As defined in the protocol, adverse events for potential immune-mediated medical conditions as well as events associated with thrombosis and thrombocytopenia were considered AESIs.

All MAAEs during the active treatment period were assessed by the investigator using the below scale: * Mild: Events that required minimal or no treatment and did not interfere with the participant's daily activities. * Moderate: Events that resulted in a low level of inconvenience or concern with the therapeutic measures. Moderate events may have caused some interference with functioning. * Severe: Events that interrupted a participant's usual daily activity and may have required systemic drug therapy or other treatment. Severe events were usually incapacitating. * Life Threatening: Any adverse drug experience that placed the participant, in the view of the investigator, at immediate risk of death from the reaction as it occurred. Participants with multiple MAAEs during the active treatment period were only counted once, the highest severity of which was used.

MAAEs were defined as TEAEs with medically-attended visits including hospital, emergency room, urgent care clinic, or other visits to or from medical personnel for any reason. Routine study visits were not considered medically-attended visits. NOCI and AESIs were collected as part of the MAAEs. As defined in the protocol, adverse events for potential immune-mediated medical conditions as well as events associated with thrombosis and thrombocytopenia were considered AESIs.

All MAAEs during the safety follow-up period were assessed by the investigator using the below scale: * Mild: Events that required minimal or no treatment and did not interfere with the participant's daily activities. * Moderate: Events that resulted in a low level of inconvenience or concern with the therapeutic measures. Moderate events may have caused some interference with functioning. * Severe: Events that interrupted a participant's usual daily activity and may have required systemic drug therapy or other treatment. Severe events were usually incapacitating. * Life Threatening: Any adverse drug experience that placed the participant, in the view of the investigator, at immediate risk of death from the reaction as it occurred. Participants with multiple MAAEs during the safety follow-up period were only counted once, the highest severity of which was used.

A TEAE was any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention, occurring after first dose of study drug. A serious TEAE was any TEAE that met any of the following criteria: * Resulted in death. * Was life-threatening. * Required inpatient hospitalization or prolongation of existing hospitalization. * Resulted in persistent or significant disability/incapacity. * Was a congenital anomaly/birth defect. * Was a suspected transmission of any infectious agent via a medicinal product. * Was a significant medical event, as judged by the investigator.

All serious TEAEs during the active treatment period were assessed by the investigator using the below scale: * Mild: Events that required minimal or no treatment and did not interfere with the participant's daily activities. * Moderate: Events that resulted in a low level of inconvenience or concern with the therapeutic measures. Moderate events may have caused some interference with functioning. * Severe: Events that interrupted a participant's usual daily activity and may have required systemic drug therapy or other treatment. Severe events were usually incapacitating. * Life Threatening: Any adverse drug experience that placed the participant, in the view of the investigator, at immediate risk of death from the reaction as it occurred. Participants with multiple serious TEAEs during the active treatment period were only counted once, the highest severity of which was used.

SARS-CoV2-specific IgG-S antibody levels were measured on specific timepoints via MSD assay. For results below the lower limit of quantification (LLOQ), the value was replaced with 1/2 the numeric portion of the original result rounded up to nearest integer. For results above the upper limit of quantification (ULOQ), the value was replaced with the numeric portion of the original result.

SARS-CoV2-specific IgG-N antibody levels were measured on specific timepoints via MSD assay. For results below the LLOQ, the value was replaced with 1/2 the numeric portion of the original result rounded up to nearest integer. For results above the ULOQ, the value was replaced with the numeric portion of the original result.

SARS-CoV2-specific IgG-RBD antibody levels were measured on specific timepoints via MSD assay. For results below the LLOQ, the value was replaced with 1/2 the numeric portion of the original result rounded up to nearest integer. For results above the ULOQ, the value was replaced with the numeric portion of the original result.

SARS-CoV2-specific IgA-S antibody levels were measured on specific timepoints via MSD assay. For results below the LLOQ, the value was replaced with 1/2 the numeric portion of the original result rounded up to nearest integer. For results above the ULOQ, the value was replaced with the numeric portion of the original result.

SARS-CoV2-specific IgA-N antibody levels were measured on specific timepoints via MSD assay. For results below the LLOQ, the value was replaced with 1/2 the numeric portion of the original result rounded up to nearest integer. For results above the ULOQ, the value was replaced with the numeric portion of the original result.

SARS-CoV2-specific IgA-RBD antibody levels were measured on specific timepoints via MSD assay. For results below the LLOQ, the value was replaced with 1/2 the numeric portion of the original result rounded up to nearest integer. For results above the ULOQ, the value was replaced with the numeric portion of the original result.

Neutralizing Serum Antibody Titers to SARS-CoV-2 were measured on specific timepoints via qualified pseudovirus assay. For results below the LLOQ, the value was replaced with 1/2 the numeric portion of the original result rounded up to nearest integer. For results above the ULOQ, the value was replaced with the numeric portion of the original result.

Mean Percentage of CD8 T-cells making TNF alpha+S were measured on specific timepoints via ICC. For results below the LLOQ, the value was replaced with 1/2 the numeric portion of the original result rounded up to nearest integer. For results above the ULOQ, the value was replaced with the numeric portion of the original result.

Mean Percentage of CD8 T-cells making IFN gamma+S were measured on specific timepoints via ICC. For results below the LLOQ, the value was replaced with 1/2 the numeric portion of the original result rounded up to nearest integer. For results above the ULOQ, the value was replaced with the numeric portion of the original result.

SARS-CoV2-specific IgA-S antibody levels in nasal swabs were measured on specific timepoints via MSD assay. For results below the LLOQ, the value was replaced with 1/2 the numeric portion of the original result rounded up to nearest integer. For results above the ULOQ, the value was replaced with the numeric portion of the original result.

SARS-CoV2-specific IgA-S antibody levels in saliva swabs were measured on specific timepoints via MSD assay. For results below the LLOQ, the value was replaced with 1/2 the numeric portion of the original result rounded up to nearest integer. For results above the ULOQ, the value was replaced with the numeric portion of the original result.