A Phase 2 randomized, multi-centric, Clinical Trial of Heterologus Prime-Boost Combination of SARS-CoV-2 Vaccines to evaluate the immunogenicity and safety of BBV152 (COVAXIN®) with BBV154 (Adenoviral Intranasal COVID-19 vaccine) in Healthy Volunteers.~This is a heterologus prime boost study, designed to evaluate the immunogenicity and safety of COVAXIN® with BBV154 and vice versa, amongthe four groups. A total of 608 subjects will be enrolled in the 1:1:1:1 ratio.~Group 1 (COVAXIN® + COVAXIN®): In this group, 152 participants will be recruited who will receive COVAXIN® on day 0 and on day 28 via the intramuscular route.~Group 2 (COVAXIN® + BBV154): In this group, 152 participants will be recruited who will receive COVAXIN® (Intramuscular) on day 0 and BBV154 (Intranasal) day 28.~*Post 56 days of vaccination, participants with seroconversion rate less than 3 folds will receive another dose of COVAXIN® viaintramuscular route~Group 3 (BBV154 + COVAXIN®): In this group, 152 participants will be recruited who will receive BBV154 (Intranasal) on day 0 and COVAXIN® (Intramuscular) on day 28.~*Post 56 days of vaccination, participants with seroconversion rate less than 3 folds will receive another dose of COVAXIN® via intramuscular route.~Group 4 (BBV154 + BBV154): In this group, 152 participants will be recruited who will receive BBV154 on day 0 and on day 28 via the intranasal route.~All participants will be assessed for immunogenicity and safety endpoints and provide a blood sample before the administration of the first dose of IP. Blood samples will be collected on days 0, 9 (Groups 1, 3 and 4), 28, 37 (Groups 2 and 4),56, 90 and 180 to assess the neutralizing antibody titer against the SARS-CoV-2 virus. A subset of 160 Participants (40 participants from each group) will be assessed for cell mediated and mucosal immunogenicity analysis, among these subset 10mL of blood and 5mL of saliva will be collected on days 0, 9 (Groups 1, 3 and 4), 28, 37 (Groups 2 and 4), 56, 90 and 180 to assess cell-mediated immunity and mucosal immunogenicity.~STUDY PROCEDURE~Visit 1(Day 0)~If the participant is eligible (in good general health or stable pre-existing disease as per the discretion of the Principal investigator), a blood sample will be withdrawn before vaccination for all the participants.~Safety Labs: An additional 15mL of blood will collected from half of the study population (76 from each group) to assess the safety at Day 0 and 56.~A blood sample (5 mL) will be collected from all the participants for immunogenicity assessment. A study vaccine/comparator will be administered. Following vaccination, participants will remain at the study site for at least 30 minutes of observation to record any immediate adverse event.~Additional 10 mL blood will be collected from subset of 160 participants (Group1:40, Group-2:40, Group 3: 40 and Group 4: 40).~A 5mL saliva sample will be collected from subset of 160 participants (Group-1:40, Group-2:40, Group 3: 40 and Group 4: 40).~Vaccine will be administered.~Diary cards will be distributed to the participants.~Telephonic follow-up (1-7-days post-vaccination) for adverse event recording.~Visit 2 (Day 9+2):~Study participants will return to the OPD for physical examination (general and systemic examination), and specific symptoms for COVID-19.~A blood sample (5 mL) will be collected from all the participants for immunogenicity assessment.~Subset of Study participants (Group 1, 3 and 4) will return to the OPD for vitals and physical examination (general and systemic examination), and specific symptoms for COVID-19.~Additional 10 mL blood will be collected from subset of (Groups 1, 3 and 4)participants(Group-1:40, Group-2:40, Group 3: 40 and Group 4: 40).~A 5mL saliva sample will be collected from subset of (Groups 1, 3 and 4) participants(Group-1:40, Group-2:40, Group 3: 40 and Group 4: 40).~Visit 3 (Day 28 +2 ):~Study participants will return to the OPD for vitals and physical examination (general and systemic examination), and specific symptoms for COVID-19.~A blood sample (5 mL) will be collected from all the participants for immunogenicity assessment.~Additional 10 mL blood will be collected from subset of 160 participants(Group1:40, Group-2:40, Group 3: 40 and Group 4: 40).~A 5mL saliva sample will be collected fromsubset of 160 participants(Group-1:40, Group-2:40, Group 3: 40 and Group 4: 40).~Vaccine will be administered.~Telephonic follow-up (1-7-days post-vaccination) for adverse event recording.~Visit 4 (Day 37±2):~Study participants will return to the OPD for physical examination (general and systemic examination), and specific symptoms for COVID-19.~A blood sample (5 mL) will be collected from all the participants for immunogenicity assessment.~Subset of Study participants (Groups 2 and 4) will return to the OPD for vitals and physical examination (general and systemic examination), and specific symptoms for COVID-19.~Additional 10 mL blood will be collected from subset of (Groups 2 and 4) participants (Group-1:40, Group-2:40, Group 3: 40 and Group 4: 40).~A 5mL saliva sample will be collected from subset of (Groups 2 and 4) participants (Group-1:40, Group-2:40, Group 3: 40 and Group 4: 40).~Visit 5 (Day 56+7):~Study participants will return to the OPD for physical examination (general and systemic examination), and specific symptoms for COVID-19.~Safety Labs: 15mL of blood will collected from half of the study population (76 from each group) to assess the safety.~A blood sample (5 mL) will be collected from all the participants for immunogenicity assessment.~Additional 10 mL blood will be collected from subset of 160 participants(Group1:40, Group-2:40, Group 3: 40 and Group 4: 40).~A 5mL saliva sample will be collected from subset of 160 participants (Group-1:40, Group-2:40, Group 3: 40 and Group 4: 40).~Visit 6 (Day 90+7):~Study participants will return to the OPD for physical examination (general and systemic examination), and specific symptoms for COVID-19.~A blood sample (5 mL) will be collected from all the participants for immunogenicity assessment.~Additional 10 mL blood will be collected from subset of 160 participants(Group1:40, Group-2:40, Group 3: 40 and Group 4: 40).~A 5mL saliva sample will be collected from subset of 160 participants(Group-1:40, Group-2:40, Group 3: 40 and Group 4: 40).~Visit 7 (Day 180+7):~Study participants will return to the OPD for physical examination (general and systemic examination), and specific symptoms for COVID-19.~A blood sample (5 mL) will be collected from all the participants for immunogenicity assessment.~Additional 10 mL blood will be collected from subset of 160 participants (Group1:40, Group-2:40, Group 3: 40 and Group 4: 40).~A 5mL saliva sample will be collected from subset of 160 participants (Group-1:40, Group-2:40, Group 3: 40 and Group 4: 40).~DSMB & report~An interim report based on the safety and immunogenicity of the vaccineswill be notified to the Data safety monitoring board and Central Drugs Standard Control Organization (CDSCO), India, for further progressing theclinical development of the vaccine. This interim report will contain a detailed analysis of the data based on the primary and secondary objectives through Day 56 (Immunogenicity & Safety).
All participants will be assessed for immunogenicity and safety endpoints and provide a blood sample before the administration of the first dose of IP. Blood samples will be collected on days 0, 9 (Groups 1, 3 and 4), 28,37 (Groups 2 and 4), 56, 90 and 180 to assess the neutralizing antibody titer against the SARSCoV-2 virus. A subset of 160 Participants (40 participants from each group) will be assessed for immunogenicity analysis, among these subset 10mL of blood and 5mL of saliva will be collected on days 0, 9 (Groups 1, 3 and 4), 28, 37 (Groups 2 and 4), 56, 90 and 180 to assess cell-mediated immunity and mucosal immunogenicity.~Group 1 (COVAXIN® + COVAXIN®): In this group, 152 participants will be recruited who will receive COVAXIN® on day 0 and on day 28 via the intramuscular route.~Group 2 (COVAXIN® + BBV154): In this group, 152 participants will be recruited who will receive COVAXIN® (Intramuscular) on day 0 and BBV154 (Intranasal) day 28.~*Post 56 days of vaccination, participants with seroconversion rate less than 3 folds will receive another dose of COVAXIN® viaintramuscular route.~Group 3 (BBV154 + COVAXIN®): In this group, 152 participants will be recruited who will receive BBV154 (Intranasal) on day 0 and COVAXIN® (Intramuscular) on day 28.~*Post 56 days of vaccination, participants with seroconversion rate less than 3 folds will receive another dose of COVAXIN® via intramuscular route.~Group 4 (BBV154 + BBV154): In this group, 152 participants will be recruited who will receive BBV154 on day 0 and on day 28 via the intranasal route.