Phase 3 N=601 Randomized Quadruple-blind Prevention

Evaluation of Full Versus Fractional Dose of COVID-19 Vaccine Given as a Booster for the Prevention of COVID-19 in Adults in Mongolia.

COVID-19

Bottom Line

View on ClinicalTrials.gov: NCT05265065 ↗

Enrolled (actual)

601

Serious AEs

0.8%

Results posted

Sep 2024

Primary outcome: Primary: Seroresponse — 253; 250 Participants

Study Design & Population

Study type: Interventional
Phase: Phase 3
Interventions: Tozinameran - Standard Dose (Biological); Tozinameran - Fractional Dose (Biological)
Age: Adult, Older Adult · 18+ yrs
Sex: All
Sponsor: Murdoch Childrens Research Institute
Primary completion: Sep 2022

Outcome Measures

Outcome	Result	p-value
PRIMARY Seroresponse	253; 250	—
PRIMARY Solicited Grade 3 or 4 Local or Systemic Reaction	6; 4	—
SECONDARY Seroresponse by Priming Vaccine Strata	55; 52; 170; 169; 28; 29	—
SECONDARY SARS-CoV-2 Specific IgG Antibodies at Day-28	4946; 4619	0.228
SECONDARY SARS-CoV-2 Specific IgG Antibodies at Day-28 by Priming Vaccine Strata	4394; 4167; 5109; 4970; 5160; 3662	0.537
SECONDARY SARS-CoV-2 Specific IgG Antibodies at Baseline (Pre-booster), 28 Days, 6 Months, 12 Months, 18 Months, and 24 Months Post-booster Vaccination.	969; 929; 4946; 4619; 2085; 2123	—
SECONDARY SARS-CoV-2 Specific Neutralising Antibodies at Baseline (Pre-booster), 28 Days, 6 Months, 12 Months, 18 Months, and 24 Months Post-booster Vaccination Measured by Surrogate Virus Neutralisation Test (sVNT).	81; 81; 81; 81; 89; 89	—
SECONDARY SARS-CoV-2 Specific Neutralising Antibodies at Baseline (Pre Booster), 28 Days-, 6- and 12-months Post Booster Vaccination Measured by SARS-CoV-2 Microneutralisation Assay	—	—
SECONDARY Interferon Gamma (IFNγ) Concentrations in International Units (IU)/mL	0.26; 0.31; 0.46; 0.60; 0.27; 0.33	—
SECONDARY Number of IFNγ Producing Cells/Million PBMCs	—	—
SECONDARY Frequency of Cytokine-expressing T Cells	—	—
SECONDARY Cellular Immunity: Multiplex Cytokine Assays - Reported as Cytokine Concentrations in pg/ml and Presented as GMC and 95% CI	—	—
SECONDARY Incidence of Unsolicited Adverse Events (AE)	5; 9; 12; 7; 5; 5	—
SECONDARY Incidence of Medically Attended Adverse Events	19; 16	—
SECONDARY Incidence of Serious Adverse Events (SAE)	6; 6; 17; 17; 4; 3	—
SECONDARY Incidence of PCR Confirmed COVID-19 Infection	14; 14	—
SECONDARY Number of IFNγ Producing Cells/Million PBMCs	—	—
SECONDARY Frequency of Cytokine-expressing T Cells	—	—
SECONDARY Cellular Immunity: Multiplex Cytokine Assays - Reported as Cytokine Concentrations in pg/ml and Presented as GMC and 95% CI	—	—

Summary

This clinical trial is a single-blind, randomised study to determine the reactogenicity and immunogenicity of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) vaccine (Pfizer-BioNTech) as booster dose in adults, who have previously received either Sinopharm (BBIBP-CorV®), AstraZeneca (ChAdOx1-S, or Vaxzevria®) or Sputnik V (Gam-COVID-Vac®) as their primary doses 6 to 9 months earlier. Both standard and fractional doses will be tested. Participants are healthy adults aged 18 years or older, with no upper age limit. Procedures will be implemented to ensure participants of all ages (aged 18 and above) are included and that there is an even age distribution (<50 and ≥50 years) in each group. There will be a total of 6 groups (Sinopharm-standard dose Pfizer, Sinopharm-fractional dose Pfizer, AstraZeneca-standard dose Pfizer, AstraZeneca-fractional dose Pfizer, Sputnik - standard dose Pfizer, Sputnik - fractional dose Pfizer), with 200 participants per group for Sinopharm and 100 for AstraZeneca and Sputnik.

Eligibility Criteria

Inclusion Criteria

Have completed two doses of Sinopharm, AstraZeneca or Sputnik vaccines with the recommended schedule 6 months prior to the date of enrolment
Willing and able to give written informed consent
Aged 18 years or above
Willing to complete the follow-up requirements of the study

Exclusion Criteria

Received 3 doses of COVID-19 vaccine
Received 2 doses of COVID-19 less than 6 months prior to the start of the trial
Currently on immunosuppressive medication or anti-cancer chemotherapy
HIV infection
Congenital immune deficiency syndrome
Has received immunoglobulin or other blood products in the 3 months prior to vaccination
Study staff and their relatives
Have a history of a severe allergic reaction to any COVID-19 vaccines or have a medical exception to receiving further COVID-19 vaccines

View full record on ClinicalTrials.gov →

Data sourced from ClinicalTrials.gov (NCT05265065). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication.