COVID PROFILE is a study of COVID-19 immunity. 

The study aims to understand more about the factors that make a person susceptible to coronavirus (SARS-CoV-2), the virus that causes COVID-19, and how infection, or vaccination, builds up a person’s immunity to the virus and for how long that protection lasts.

This study is addressing these questions in two key ways:

  • comparing immune responses between people who have experienced coronavirus infection with those who have not been infected
  • comparing an individual’s immune response before and after receiving a COVID-19 vaccine to those who acquired an immune response as a result of a COVID-19 infection


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Why are you conducting a study of people’s immune responses to COVID-19?

In most cases, when people get infected with SARS-CoV-2, the virus that causes COVID-19, the immune system quickly marshals its defences. The symptoms remain modest and clear up quickly, after the infection is eliminated. However, in some patients this defence does not work as effectively, and the patient will develop severe disease.

Importantly, we still do not understand what aspects of a person’s immune response result in mild versus severe infection and, critically, we do not know how long COVID-19 immunity lasts and protects people after they have recovered. 

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How will this study help us fight COVID-19?

Understanding why some people get severely ill, while others do not, will help us identify biomarkers to predict which people are at higher risk of developing severe disease and may need extra medical assistance. It will also enable us to find new treatments that can help strengthen people’s immune systems to help them recover faster.

A better knowledge of how immunity to COVID-19 is acquired and how long it lasts is essential to developing effective vaccines and vaccination strategies. 

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Who can participate in the study?

An infection with COVID-19 changes the immune system. To understand exactly how, we need to study both people who have had COVID-19, as well as people who haven’t had COVID-19. This comparison allows us to better identify how immune responses contribute to COVID-19 symptoms, recovery and future protection.

We are also looking for participants who have not had exposure to COVID-19 but who intend to receive a COVID-19 vaccine. We will follow these participants before and after vaccination, to measure changes in their immune responses over time.

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What results has the study found so far?

Interim analysis of the results of the study have found that one third of COVID-19 patients in the study were still experiencing Long COVID symptoms up to 45 weeks post-diagnosis. 

Most people showed robust antibody responses for up to 100 days after diagnosis. But 16 per cent of patients in the study had no detectable SARS-CoV-2-specific antibodies six months after diagnosis.

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What samples will you be collecting?

We can best study the immune system by looking at white blood cells and antibodies in your blood. The study will collect blood samples at regular intervals throughout the course of 12 months. To find out how the environment in the nose and throat may affect people’s immunity, we will also ask permission to collect nasal swabs and saliva.

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Is it okay to have the COVID-19 or flu vaccines while on the study? 

Yes. Study participants are not asked to make any changes to their normal medications, treatments or planned vaccinations while taking part in the study.

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Why do you need to study people for 12 months after they have had COVID-19?

In most infections, immunity is strongest at the point of recovery. After that, it starts decreasing. In some infections, such as influenza, immunity rapidly wanes, and people can become re-infected as quickly as six months later. In other infections, such as measles, the protection is life-long, and people cannot become reinfected with the virus. 

By studying how your immune responses change during the 12 months after you have recovered, we can identify if and how immune memory is built up and predict how long it may last. 

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How is the study conducted under lockdown restrictions?

As we plan to collect regular samples from participants, the study remains operational even when lockdown restrictions are in place.

Arrangements can be made to ensure people participating in the study can do so in a COVID-safe manner.

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Why are you also studying people who have not had COVID-19?

An infection with COVID-19 changes the immune system. To understand exactly how, we need to also study how the immune system is prepared to fight infection in people who have never had COVID-19. This comparison allows us to better identify how immune responses contribute to symptoms, recovery and future protection.

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I haven’t had COVID-19, can I still participate? 

Yes. For this study, in addition to recruiting people who have recovered from COVID-19, we are also recruiting participants who have not had the disease but intend to have a COVID-19 vaccine.

At this stage we are only recruiting participants aged 18 years and older, in greater Melbourne.

If you are not eligible to participate in the COVID PROFILE study, you may still be able to help WEHI's research efforts by volunteering for the Volunteer Blood Donor Registry

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I have already received a COVID-19 vaccine, can I still participate?

No, to study your immune response following vaccination to COVID-19, you will need to enrol prior to vaccination so your immune system before and after vaccination. Please contact us if you have any further questions. 

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Are other studies investigating immunity to COVID-19?

Many scientists around the world are studying immune responses to COVID-19. Our team is working closely with our scientific and clinical colleagues across Australia and internationally to contribute to these efforts. 

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How does this study differ from other studies of COVID-19?

Our study differs from most other studies in the breadth and depth of immune factors it is looking at. Our team of immunologists and infectious disease researchers are conducting multi-level analyses to allow us to look at how the different parts of the immune system combine to respond to COVID-19, in order to gain a better understanding of the factors that contribute to people’s risk of contracting the virus and their protection against reinfection. 

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Is this study needed now that vaccines are available?

Understanding immunity to coronavirus, how it is established, and how long it is protective against new infections will be critical for vaccination strategies. How frequently we may need boosters or re-vaccination, if at all, is an important aspect of the study. We also want to identify vulnerable groups that may need additional vaccination or alternative therapeutic strategies.

The vaccination component of our study will investigate this area in detail. If you intend to get a COVID-19 vaccination, check your eligibility to participate.

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Will the study continue if the number of COVID-19 cases is low?

Even when cases in Victoria are low, our study is of critical importance to understand local immunity to SARS-CoV-2.

We are also conducting studies of samples collected from recovered people around the world, including from high-transmission areas where the risk of infection and re-infection is very high.  

Comparing results of these studies with our local Victorian participants will provide us with a better picture of the risk of reinfection and how long different aspects of immune protection last in different groups of people.

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Are there any risks associated with participation in the study?

The study does not involve any treatment or intervention. We are simply following participants by collecting and analysing blood samples and nasal swabs, using standard procedures. These collections will be conducted by trained nurses and will involve only mild discomfort for the participant.  

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How will you ensure the privacy of participants?

Once samples have been collected, they are coded with a number that cannot be traced to individual participants by the research team. Only the nurse collecting the samples, the project manager and the principal investigators will have access to your personal details. Personal information will be stored in a password protected database.

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Can all people who have been diagnosed with COVID-19 participate in the study?

We are prioritising participation from people who are living in the Greater Melbourne area. 

However, if you live in regional Victoria, please register your interest. We will contact you and may invite you to participate.

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How can I participate in the study?

People living in Victoria who have had COVID-19 can check their eligibility and register their details here. Once you have registered, by providing your contact details, our study team will contact you to further explain the study, discuss your possible participation and answer any questions you may have.

This study is not open to participants outside Victoria.

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Who is funding the COVID PROFILE study?

The study is being funded by WEHI, the World Health Organisation’s UNITY study and philanthropic supporters.

The study is not currently funded by any other government, private or industry sources.

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Who approved the COVID PROFILE study?

COVID PROFILE has been reviewed and approved by the independent Human Research Ethics Committee (HREC) of WEHI and the Melbourne Health HREC. 

COVID PROFILE conforms to the National Health and Medical Research Council (NHMRC) Statement on Ethical Conduct in Human Research.

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If you are interested in participating in the COVID PROFILE study please complete our eligibility survey:

Check your eligibility


Further information

Visualisation of SARS-CoV-2

Our researchers are working towards better approaches to diagnose, treat and prevent the spread of coronaviruses, both to address the current COVID-19 global outbreak as well as in preparedness for likely future coronaviral disease outbreaks.

Three researchers in a laboratory

The COVID PROFILE study will use blood samples from people who have recovered from COVID-19, and their close contacts, to look in detail at how immunity to the disease develops, how long it lasts and what happens when immunity is lost. 

Patient receiving a vaccination

We answer some popular questions about the vaccine rollout in Australia.