NCT05593042

Immunogenicity Evaluation of Omicron Variant-based Vaccine and a Trivalent Vaccine in Adults Against COVID-19 in Chile

Phase 2, Randomized, Double-blind Study to Evaluate Immunogenicity Superiority of a Booster Dose With an Omicron or a Trivalent Vaccine Compared to CoronaVac, in Adults Immunized With Different Vaccine Schedules Against SARS-CoV-2 in Chile

• Status: Completed
• Phase: Phase 2
• Study type: Interventional
• Enrollment: 551 (actual)
• Sponsor: Pontificia Universidad Catolica de Chile · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Accepted

Summary

Phase 2 clinical trial in adults previously vaccinated against SARS-CoV-2 in Chile with an initial schedule of two doses of CoronaVac® plus two booster doses with different vaccines. Subjects will randomly receive a third booster dose with Omicron, trivalent, or CoronaVac® vaccine. The humoral immunogenicity against COVID-19 will be compared in subjects that received the Omicron or the Trivalent vaccines with subjects that received CoronaVac® to determine the superiority of the two candidate vaccines versus CoronaVac®. Subjects will be followed for 6 months after the booster dose administration.

Detailed description

This study will be a phase 2 randomized, double-blind, multicenter clinical trial in fully vaccinated adults, males, and females, who have previously received an initial schedule of two doses of CoronaVac® plus two booster doses with different vaccines against SARS-CoV-2 in Chile. Two groups of participants will be included: Heterologous group: subjects who had received two booster doses with mRNA or viral vector-based vaccine); and homologous group: subjects who have received two booster doses of CoronaVac® in a previous clinical trial (CoronaVac03CL). Subjects of the heterologous group will randomly receive a booster dose with Omicron, trivalent, or CoronaVac® vaccine. On the other hand, subjects of the homologous group will randomly receive a booster dose of Omicron or trivalent vaccine. The humoral immunogenicity against COVID-19 will be compared in subjects of the heterologous group that will receive Omicron or trivalent vaccine with subjects that will receive CoronaVac®, to determine the superiority of the two candidate vaccines versus CoronaVac®. Subjects will be followed for 6 months after the booster dose administration.

Conditions

• COVID-19
• Vaccines

Interventions

Type	Name	Description
BIOLOGICAL	CoronaVac®	The active ingredient is the SARS-CoV-2 virus (CZ02 strain, ancestral) grown in Vero cells and inactivated, in aluminum hydroxide. The vaccine is preservative-free, and it is packed in pre-load syringes (0.5 mL) with 600 SU/0.5mL of inactivated SARS-CoV-2.
BIOLOGICAL	Omicron Vaccine	An experimental intervention consisting of a booster dose of an inactivated Omicron variant vaccine. The active ingredient is the SARS-CoV-2 virus (Omicron variant) grown in Vero cells and inactivated, in aluminum hydroxide. The vaccine is preservative-free, packed in a pre-load syringe, and contains one dose (0.5mL) of 1200 SU of inactivated SARS-CoV-2 Omicron variant.
BIOLOGICAL	Trivalent Vaccine	An experimental intervention consisting of a booster dose of an inactivated trivalent (CZ02 strain, ancestral, Delta, and Omicron variants) variant vaccine. The active ingredient is the SARS-CoV-2 virus (CZ02 strain, ancestral, Delta, and Omicron variants) grown in Vero cells and inactivated, in aluminum hydroxide. The vaccine is preservative-free, and it is packed in a pre-load syringe containing one dose (0.5mL) (1200 SU of inactivated SARS-CoV-2 WT, 1200 SU of inactivated SARS-CoV-2 Delta variant, and 1200 SU of inactivated SARS-CoV-2 Omicron variant).

Timeline

• Start date: 2022-11-28
• Primary completion: 2023-10-26
• Completion: 2023-10-26
• First posted: 2022-10-25
• Last updated: 2024-02-07

Locations

3 sites across 1 country: Chile