Study of Recombinant Protein Vaccine Formulations Against COVID-19 in Healthy Adults 18 Years of Age and Older

Geometric Mean Titers (GMTs) of Neutralizing Antibodies Against SARS-CoV-2 Recombinant Protein Vaccine Formulations at Day 1

GMTs of SARS-CoV-2 neutralizing antibodies was measured using a neutralization assay. Titers were expressed in terms of 1/dilution.

Time frame: Day 1 (pre-vaccination)

Geometric Mean Titers of Neutralizing Antibodies Against SARS-CoV-2 Recombinant Protein Vaccine Formulations at Day 22

GMTs of SARS-CoV-2 neutralizing antibodies was measured using a neutralization assay. Titers were expressed in terms of 1/dilution.

Time frame: Day 22 (post-vaccination)

Geometric Mean Titers of Neutralizing Antibodies Against SARS-CoV-2 Recombinant Protein Vaccine Formulations at Day 36

GMTs of SARS-CoV-2 neutralizing antibodies was measured using a neutralization assay. Titers were expressed in terms of 1/dilution.

Time frame: Day 36 (post-vaccination)

Geometric Mean Fold-rise (GMFR) of Serum Neutralization Antibody Titers at Day 22

SARS-CoV-2 neutralizing antibodies was measured using a neutralization assay. Fold-rise was calculated as the ratio of titer values of neutralizing antibodies post-vaccination (Day 22) and pre-vaccination (on Day 1) i.e., Day 22/Day 1.

Time frame: Day 1 (pre-vaccination) and Day 22 (post-vaccination)

Geometric Mean Fold-rise of Serum Neutralization Antibody Titers at Day 36

SARS-CoV-2 neutralizing antibodies was measured using a neutralization assay. Fold-rise was calculated as the ratio of titer values of neutralizing antibodies post-vaccination (Day 36) and pre-vaccination (on Day 1) i.e., Day 36/Day 1.

Time frame: Day 1 (pre-vaccination) and Day 36 (post-vaccination)

Number of Participants With >=2-fold and >=4-fold Rise in Serum Neutralization Antibody Titers at Day 22

SARS-CoV-2 neutralizing antibodies was measured using a neutralization assay. The fold rise (2-fold and 4-fold) was calculated as the ratio of titer values of neutralizing antibodies post-vaccination (on Day 22) and pre-vaccination (on Day 1) i.e., Day 22/Day 1.

Time frame: Day 1 (pre-vaccination) and Day 22 (post-vaccination)

Number of Participants With >=2-Fold and >=4-Fold Rise in Serum Neutralization Antibody Titer at Day 36

SARS-CoV-2 neutralizing antibodies was measured using a neutralization assay. The fold rise (2-fold and 4-fold) was calculated as the ratio of titer values of neutralizing antibodies post-vaccination (on Day 36) and pre-vaccination (on Day 1) i.e., Day 36/Day 1.

Time frame: Day 1 (pre-vaccination) and Day 36 (post-vaccination)

Percentage of Participants Achieving Seroconversion Against SARS-CoV-2 Virus Antigens at Day 22

Seroconversion was defined as participants with a Baseline (Day 1) titer value below lower limit of quantification (LLOQ) with a detectable neutralization antibody titer above assay LLOQ post vaccination (at Day 22). LLOQ of the neutralization assay was a titer of 10.

Time frame: Day 22 (post-vaccination)

Percentage of Participants Achieving Seroconversion Against SARS-CoV-2 Virus Antigens at Day 36

Seroconversion was defined as participants with a Baseline (Day 1) titer value below LLOQ with a detectable neutralization antibody titer above assay LLOQ post vaccination (at Day 36). LLOQ of the neutralization assay was a titer of 10.

Time frame: Day 36 (post-vaccination)

Number of Participants With Immediate Unsolicited Adverse Events (AEs)

An AE was defined as any untoward medical occurrence in a participant who received study vaccine and does not necessary had to have a causal relationship with treatment. An unsolicited AE was an observed AE that did not fulfill the conditions of solicited reactions prelisted in the case report form (CRF) in terms of diagnosis and/or onset window post-vaccination. All participants were observed for 30 minutes after vaccination, and any unsolicited systemic AEs occurred during that time were recorded as immediate unsolicited AEs in the CRF. Reported AEs for each arm were presented as pre-specified in the study protocol.

Time frame: Within 30 minutes post any and each vaccination (Vaccination 1 [i.e., at Day 1] and 2 [i.e., at Day 22])

Number of Participants With Solicited Injection Site Reactions

A solicited reaction (SR) was defined as an "expected" adverse reaction (AR) (sign or symptom) observed and reported under the conditions (nature and onset) prelisted (i.e., solicited) in the protocol and CRF and considered as related to vaccination. Solicited injection site reactions included pain, erythema and swelling. Reported AEs for each arm were presented as pre-specified in the study protocol.

Time frame: Within 7 days post any and each vaccination (Vaccination 1 [i.e., at Day 1] and 2 [i.e., at Day 22])

Number of Participants With Solicited Systemic Reactions

An SR was defined as an "expected" AR (sign or symptom) observed and reported under the conditions (nature and onset) prelisted (i.e., solicited) in the protocol and CRF and considered as related to vaccination. Solicited systemic reactions included fever, headache, malaise and myalgia. Reported AEs for each arm were presented as pre-specified in the study protocol.

Time frame: Within 7 days post any and each vaccination (Vaccination 1 [i.e., Day 1] and 2 [i.e., Day 22])

Number of Participants With Unsolicited Adverse Events

An AE was defined as any untoward medical occurrence in a participant who received study vaccine and does not necessary had to have a causal relationship with treatment. An unsolicited AE was an observed AE that did not fulfill the conditions of solicited reactions prelisted in the CRF in terms of diagnosis and/or onset post-vaccination. Reported AEs for each arm were presented as pre-specified in the study protocol.

Time frame: Within 21 days post any and each vaccination (Vaccination 1 [i.e., Day 1] and 2 [i.e., Day 22])

Number of Participants With Medically Attended Adverse Events (MAAE)

A MAAE were AEs with a new onset or a worsening of a condition that prompted the participant to seek unplanned medical advice at a physician's office (including phone contact or email) or emergency department. An AE was defined as any untoward medical occurrence in a participant who received study vaccine and does not necessarily had to have a causal relationship with treatment. Reported AEs for each arm were presented as pre-specified in the study protocol.

Time frame: From Day 1 up to 12 months post last vaccination (i.e., up to Day 366 for Cohort 1 and up to Day 387 for Cohort 2)

Number of Participants With Serious Adverse Events (SAE)

An SAE was any untoward medical occurrence that at any dose 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, or was an important medical event. Reported AEs for each arm were presented as pre-specified in the study protocol.

Time frame: From Day 1 up to 12 months post last vaccination (i.e., up to Day 366 for Cohort 1 and up to Day 387 for Cohort 2)

Number of Participants With Adverse Events of Special Interest (AESIs)

An AESI (serious or non-serious) was defined as one of scientific and medical concern specific to the Sponsor's product or program, for which ongoing monitoring and rapid communication by the Investigator to the Sponsor was appropriate. Reported AEs for each arm were presented as pre-specified in the study protocol.

Time frame: From Day 1 up to 12 months post last vaccination (i.e., up to Day 366 for Cohort 1 and up to Day 387 for Cohort 2)

Number of Participants With Laboratory Test Results Based on US FDA Toxicity Grading Guidance

Laboratory tests included hemoglobin (male and female), above and below normal white blood cell, lymphocytes, neutrophils \& eosinophils, platelet count, creatinine and blood urea nitrogen, hyponatremia \& hypernatremia, hyperkalemia \& hypokalemia, hyperglycemia (non-fasting), hypoproteinemia, alkaline phosphate, alanine aminotransferase, aspartate aminotransferase, bilirubin (with any increase in liver function test \[LFT\], bilirubin (normal in LFT), amylase \& lipase, Urine: protein, glucose \& blood. The US FDA Guidance for Industry "Toxicity Grading Scale for Healthy Adults and Adolescent Volunteers Enrolled in Preventive Vaccine Clinical Trials" was used for grading. As per the guidance, Grade 1 = mild, Grade 2 = moderate and Grade 3 = severe.

Time frame: From Day 1 up to 8 days post last dose (i.e., up to Day 9 for Cohort 1 and up to Day 30 for Cohort 2)