AzTrials
AzTrials

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.

Unknown status

Status not confirmed. The sponsor has not verified this record for over two years, so it may be out of date.

Official record
Search all trials

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 Observational, unpublished data also indicate that vaccine effectiveness against Covid-19 wanes over time.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

Other trials in Chile

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 Observational, unpublished data also indicate that vaccine effectiveness against Covid-19 wanes over time.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 groups in NCT04992182
Study groupRoleWhat they receive
Inactivated vaccine boosterExperimentalOne standard IM CoronaVac dose (0.5 mL)
Receives: Biological: Inactivated vaccine booster
mRNA vaccine boosterExperimentalOne standard IM BNT162b2 dose (0.3 mL)
Receives: Biological: mRNA vaccine booster
Viral vector vaccine boosterExperimentalOne standard IM ChAdOx1 dose (0.5 mL)
Receives: Drug: Viral vector vaccine booster
PlaceboPlacebo comparatorSaline 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.

  1. 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

  2. Immunogenicity

    Change in SARS-CoV-2 neutralizing antibody levels

    Measured: Baseline, 15, 30, 60, and 90 days post booster dose

Secondary outcomes (2)
  1. 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

  2. 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.

  1. First posted5 Aug 2021
  2. Study start8 Jul 2021
  3. Primary completion31 Aug 2021 (estimated)
  4. Study completion30 Jun 2022 (estimated)

Resources

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)
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).

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.

Free account

Log in to keep searching

You’ve used your 3 free searches. AzTrials is free: log in or create a free account to keep searching clinical trials and save the ones you want to follow.

Create a free accountLog in