Covid19Phase 2REFUERZONCT04992182
Reactogenicity, Safety, and Immunogenicity of Covid-19 Vaccine Booster
A Phase 2 study testing Inactivated vaccine booster, mRNA vaccine booster and Viral vector vaccine booster in people with Covid19, run by Universidad del Desarrollo at 2 sites in Chile.
Trial summary
Preliminary data suggest that inactivated vaccine-induced neutralizing antibodies against SARS-CoV-2 decrease at six months after vaccination. Observational, unpublished data also indicate that vaccine effectiveness against Covid-19 wanes over time. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Covid19
- What is being tested?
- Inactivated vaccine booster, mRNA vaccine booster and Viral vector vaccine booster
- Type of treatment
- Vaccines
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 534 participants
- Where
- 2 sitesChile
- Study dates
- 8 Jul 2021to 30 Jun 2022
- Phase
- Phase 2
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Full immunization with CoronaVac (2 doses; 0,28) prior to April 15, 2021
- Being a resident of any of the eligible Nursing Homes (located in the Metropolitan Region of Chile)
- Healthcare workers of one of the eligible Nursing Homes.
- Healthcare workers of Hospital de Urgencia Asistencia Publica (HUAP, Santiago, Chile)
Who cannot join
- Prior history of Covid-19
- Not able to consent
Trial locations and contacts
2 sites in 1 country.
Chile2 sites
ELEAMs (Nursing Homes)
Santiago
Hospital de Urgencia Asistencia Publica
Santiago
About this study
Official title: Reactogenicidad, Seguridad e Inmunogenicidad de Dosis de Refuerzo de Vacunas Contra SARS-CoV-2 en Chile (Estudio REFUERZO)
Preliminary data suggest that inactivated vaccine-induced neutralizing antibodies against SARS-CoV-2 decrease at six months after vaccination. Observational, unpublished data also indicate that vaccine effectiveness against Covid-19 wanes over time. Thus, the investigators aimed to determine the reactogenicity, safety, and immunogenicity of a homologous or heterologous booster of SARS-CoV-2 vaccines among people already immunized with an inactivated SARS-CoV-2 vaccine. The study focuses on the elderly population and healthcare workers.
- Conditions
- Covid19
- Being tested
- Placebo, Inactivated vaccine booster, mRNA vaccine booster, Viral vector vaccine booster
- Keywords
- covid-19, inactivated vaccine, booster, Chile
- Medical subject headings
- COVID-19
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PlaceboBiological
0.3 mL IM saline solution
Inactivated vaccine boosterBiological
Also called CoronaVac
0.5 mL IM
mRNA vaccine boosterBiological
Also called BNT162b2
0.3 mL IM
Viral vector vaccine boosterDrug
Also called ChAdOx1
0.5 mL IM
| Study group | Role | What they receive |
|---|---|---|
| Inactivated vaccine booster | Experimental | One standard IM CoronaVac dose (0.5 mL) Receives: Biological: Inactivated vaccine booster |
| mRNA vaccine booster | Experimental | One standard IM BNT162b2 dose (0.3 mL) Receives: Biological: mRNA vaccine booster |
| Viral vector vaccine booster | Experimental | One standard IM ChAdOx1 dose (0.5 mL) Receives: Drug: Viral vector vaccine booster |
| Placebo | Placebo comparator | Saline solution IM (0.3 mL) Receives: Biological: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Early humoral response
Change in SARS-CoV-2 neutralizing antibody levels
Measured: Baseline (90-120 days after second dose of CoronaVac) and 15 days post booster dose
Immunogenicity
Change in SARS-CoV-2 neutralizing antibody levels
Measured: Baseline, 15, 30, 60, and 90 days post booster dose
Secondary outcomes (2)
Reactogenicity
Solicited and unsolicited. Events will be assessed by scheduled visits performed by nursing home´s nurse stuff. Telephone numbers, including the PI´s cell phone will be available 24/7 for reporting any unsolicited reaction. Reporting will follow national regulations available at the Institute of Public Health web page (https://www.ispch.cl/anamed/farmacovigilancia/vacunas/como-notificar-esavi/)
Measured: days 7, 28, and 3 months post booster dose
Safety of booster dose
Number of subjects presenting serious adverse events post booster dose.
Measured: In addition to the scheduled visits mentioned in Outcome 3, Telephone numbers, including the PI´s cell phone will be available 24/7 throughout the study (1 year) for reporting any unsolicited reaction.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Aug 2021
- Study start8 Jul 2021
- Primary completion31 Aug 2021 (estimated)
- Study completion30 Jun 2022 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Covid19Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 534 participants (actual)
Sponsor and investigators
- Lead sponsor
- Universidad del Desarrollo
- Sponsor type
- University, hospital or other
- Collaborators
- Ministry of Health, Chile, University of Chile, Pontificia Universidad Catolica de Chile
- Responsible party
- Principal investigator, Rafael Araos, Universidad del Desarrollo
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04992182
- Sponsor's protocol ID
- 2021-71
- Acronym
- REFUERZO
- Status last verified
- Aug 2021
- First submitted
- 2 Aug 2021
- Last updated
- 5 Aug 2021
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No: Owing to data privacy regulations, the individual-level data in this study cannot be shared (Law N19.628).
Study at a glance
From the registry record, last updated by the sponsor on 5 Aug 2021. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Reactogenicidad, Seguridad e Inmunogenicidad de Dosis de Refuerzo de Vacunas Contra SARS-CoV-2 en Chile (Estudio REFUERZO)
- ClinicalTrials.gov ID
- NCT04992182
- Acronym / sponsor ID
- REFUERZO / 2021-71
- Conditions
- Covid19
- Keywords
- covid-19, inactivated vaccine, booster, Chile
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Unknown status
- Enrolment
- 534 participants (actual)
- Lead sponsor
- Universidad del DesarrolloUniversity, hospital or other
- Collaborators
- Ministry of Health, Chile, University of Chile, Pontificia Universidad Catolica de Chile
- Study start
- 8 Jul 2021 (actual)
- Primary completion
- 31 Aug 2021 (estimated)
- Study completion
- 30 Jun 2022 (estimated)
- First posted
- 5 Aug 2021 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Preliminary data suggest that inactivated vaccine-induced neutralizing antibodies against SARS-CoV-2 decrease at six months after vaccination. Observational, unpublished data also indicate that vaccine effectiveness against Covid-19 wanes over time. Thus, the investigators aimed to determine the reactogenicity, safety, and immunogenicity of a homologous or heterologous booster of SARS-CoV-2 vaccines among people already immunized with an inactivated SARS-CoV-2 vaccine. The study focuses on the elderly population and healthcare workers.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, investigator)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| Inactivated vaccine booster | Experimental | Biological: Inactivated vaccine boosterOne standard IM CoronaVac dose (0.5 mL) |
| mRNA vaccine booster | Experimental | Biological: mRNA vaccine boosterOne standard IM BNT162b2 dose (0.3 mL) |
| Viral vector vaccine booster | Experimental | Drug: Viral vector vaccine boosterOne standard IM ChAdOx1 dose (0.5 mL) |
| Placebo | Placebo comparator | Biological: PlaceboSaline solution IM (0.3 mL) |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Full immunization with CoronaVac (2 doses; 0,28) prior to April 15, 2021
- Being a resident of any of the eligible Nursing Homes (located in the Metropolitan Region of Chile)
- Healthcare workers of one of the eligible Nursing Homes.
- Healthcare workers of Hospital de Urgencia Asistencia Publica (HUAP, Santiago, Chile)
Key exclusion criteria (2 listed)
- Prior history of Covid-19
- Not able to consent
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Placebo0.3 mL IM saline solution | Biological | Placebo |
| Inactivated vaccine boosterAlso: CoronaVac0.5 mL IM | Biological | Inactivated vaccine booster |
| mRNA vaccine boosterAlso: BNT162b20.3 mL IM | Biological | mRNA vaccine booster |
| Viral vector vaccine boosterAlso: ChAdOx10.5 mL IM | Drug | Viral vector vaccine booster |
Primary outcome
Early humoral response
Time frame: Baseline (90-120 days after second dose of CoronaVac) and 15 days post booster dose
Change in SARS-CoV-2 neutralizing antibody levels
Immunogenicity
Time frame: Baseline, 15, 30, 60, and 90 days post booster dose
Change in SARS-CoV-2 neutralizing antibody levels
2 secondary outcomes
Reactogenicity
Time frame: days 7, 28, and 3 months post booster dose
Safety of booster dose
Time frame: In addition to the scheduled visits mentioned in Outcome 3, Telephone numbers, including the PI´s cell phone will be available 24/7 throughout the study (1 year) for reporting any unsolicited reaction.
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 5 Aug 2021.
- Individual participant dataSharing planned: No. Owing to data privacy regulations, the individual-level data in this study cannot be shared (Law N19.628).
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Inactivated vaccine booster, mRNA vaccine booster and Viral vector vaccine booster in people with Covid19, run by Universidad del Desarrollo at 2 sites in Chile.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 2 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: status not confirmed, as of the sponsor's last update on 5 Aug 2021. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in Chile. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Early humoral response (time frame: Baseline (90-120 days after second dose of CoronaVac) and 15 days post booster dose). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 5 Aug 2021; AzTrials last refreshed its copy on 7 Nov 2026.