Evaluation of Full Versus Fractional Doses of COVID-19 Vaccines Given as a Booster in Adults in Australia - Mongolia, Indonesia, Australia Coronavirus (MIACoV).

Phase 3TerminatedNCT05228730

Murdoch Childrens Research Institute13 enrolled

Overview

This is a single-blind, randomised controlled clinical trial to determine the reactogenicity and immunogenicity of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) vaccines (Pfizer-BioNTech or Moderna) as booster dose in adults, who have previously received either Pfizer-BioNTech or AstraZeneca as their primary doses. Both fractional and standard doses of Pfizer-BioNTech or Moderna will be tested. The trial intervention will be given in line with Australian Technical Advisory Group on Immunisation (ATAGI) recommendations for booster vaccine doses which allows booster doses from 5 months onwards . There will be a total of 8 groups, with 100 individuals of even spread of participants above and below 50 years in each group. The trial will be single site, based at Royal Children's Hospital, Melbourne, Australia

As per brief summary

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

DOUBLE

Enrollment

Conditions

COVID-19

Interventions

Tozinamrean is a single-stranded, 5'-capped messenger RNA (mRNA) produced using a cell-free in vitro transcription from the corresponding DNA templates, encoding the viral spike (S) protein of severe acute respiratory syndrome coronavirus 2 (SARS\_CoV-2). A standard dose will be administered on day 0 of the study.

Tozinameran - fractional doseBIOLOGICAL

Tozinamrean is a single-stranded, 5'-capped messenger RNA (mRNA) produced using a cell-free in vitro transcription from the corresponding DNA templates, encoding the viral spike (S) protein of severe acute respiratory syndrome coronavirus 2 (SARS\_CoV-2). A fractional dose (15mcg) of the intervention will be administered on day 0 of the study.

Elasomeran - standard doseBIOLOGICAL

Elasomeran is a single-stranded, 5'-capped messenger RNA (mRNA) produced using a cell-free in vitro transcription from the corresponding DNA templates, encoding the viral spike (S) protein of SARS-CoV-2). A single standard dose (50mcg) of the intervention will be administered on day 0 of the study.

Elasomeran - fractional doseBIOLOGICAL

Elasomeran is a single-stranded, 5'-capped messenger RNA (mRNA) produced using a cell-free in vitro transcription from the corresponding DNA templates, encoding the viral spike (S) protein of SARS-CoV-2). A fractional dose (20mcg) of the intervention will be administered on day 0 of the study.

Eligibility

Sex: ALLMin age: 18 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: 1. Have completed two doses of Pfizer-BioNTech or AstraZeneca vaccines with the recommended schedule 6 months prior to the date of enrolment 2. Willing and able to give written informed consent 3. Aged 18 years or above 4. Willing to complete the follow-up requirements of the study Exclusion Criteria: 1. Received 3 doses of COVID-19 vaccine 2. Received 2 doses of COVID-19 less than 6 months prior to the start of the trial 3. Received a different Covid-19 vaccine not available in Australia 4. Currently on immunosuppressive medication or anti-cancer chemotherapy 5. HIV infection 6. Congenital immune deficiency syndrome 7. Has received immunoglobulin or other blood products in the 3 months prior to vaccination 8. Study staff and their relatives 9. Have a history of a severe allergic reaction to any COVID-19 vaccines or have a medical exception to receiving further COVID-19 vaccines 10. Cannot read or understand English

Outcomes

Primary Outcomes

SARS-CoV-2 Specific Immunoglobulin (Ig)G Antibodies at 28-days Post Booster Vaccination

Serum samples collected at 28-days post booster vaccination from all groups will be evaluated for SARS-CoV-2 specific IgG antibodies using the commercial Euroimmun S1 IgG ELISA. Data will be reported as binding antibody units/mL and presented as geometric mean concentration and 95% confidence intervals

Time frame: 28-days post booster vaccination.