Information for people interested in vaccine studies in light of news about other promising COVID vaccines

Important information for patients and the public

Thank you for your interest in COVID-19 vaccine research.

The Pfizer/BioNTech and Oxford/AstraZeneca vaccines are now being rolled out across the UK. In addition, the Moderna vaccine has become the third COVID-19 vaccine to be approved for use in the UK.

These developments are a tribute to the global efforts of the life sciences industry, researchers and volunteers, underlining the importance of this vaccine research. It is thanks to you and all those involved, that we have this encouraging news about vaccines.

It is important that clinical trials into a number of other COVID-19 vaccines continue. Different vaccines work in different ways and we still need to collect important information about which vaccines work best, and are best for different groups of people, and on exactly how effective they are at, for example, preventing severe infection, preventing infection as a whole, preventing transmission etc. We also need information on matters such as the best way to use vaccines, the number of doses, and to check long term that there are no safety concerns.

Keep taking part

It is really important that people keep taking part in all the COVID-19 studies, attending their follow-up appointments and submitting data on their health and COVID infections. We need volunteers to join new studies and existing studies are not yet complete, and we need the long term data to help us understand how best to use the vaccines, which are most effective and to give information on the levels of effectiveness, as well as reassurance on long term safety of them.

Here are some answers to questions you might have about what these developments mean for the clinical study you are taking part in.


Do we still need people to take part in COVID vaccine trials?

Yes, the trials will continue because we need data about a number of different vaccines and their safety and effectiveness, in order to protect the population.

We need several vaccines to ensure an adequate supply and because some vaccines may be easier to transport and store than others. We need further data on whether one or other vaccine is better suited to specific groups of people, such as older people or people with other medical conditions, and all the trials are giving information on safety, which is so important to gather.

Thank you for your participation - it is thanks to people taking part in trials that we have approved vaccines.

What will the roll out of the approved vaccines mean for the trials?

The NHS will call people up in an agreed priority order in the coming weeks and months to be vaccinated. We would want everyone taking part in the trials to be protected, alongside the rest of the population. Your safety is our highest priority. We are working on a process to make sure that trial participants are protected either through one of the approved vaccines or the trial vaccine.

I'm on a clinical trial and in a priority group for vaccination, how will I be offered early protection?

Now that an approved vaccine is available, people in priority groups will be contacted by the NHS and offered an appointment to receive it.

From February 2021, this includes people over 70, health and care workers and people who are extremely clinically vulnerable, and is being rolled out by age to younger people. When you are invited to a vaccine, please contact the research team, who will follow an agreed process to advise you. This is likely to include finding out whether you received an active trial vaccine or a placebo (that would offer you no protection against COVID-19), called ‘unblinding’.

If you had an active vaccine, the research team will advise you if you still need to have the approved vaccine, taking into account the latest data on the trial vaccine’s effectiveness. If you had a placebo, you will be advised to have the approved vaccine.

Please continue to attend follow-up appointments and the advice of the research team, so that we can gather important safety information about the trial vaccine. It will be important that we gather information about the safety and effectiveness of all the trial vaccines underway. This is so that we can gather information to allow use of all the effective vaccines, to maximise supply and ensure that we gain a full picture of the effectiveness and use of all the vaccines available.

I’m on a clinical trial and not in a priority group for vaccination, what does this mean for me?

Please continue to take part in the clinical trials, attend for your follow-up booster (if applicable), and all your follow-up appointments. People will be called up by the NHS to be offered a vaccine in a priority order determined by experts, based on how at risk they are of becoming ill with or spreading severe infection. 

It is likely to take some time for healthy people under 50 years of age to be invited to receive an approved vaccine, which could mean many months. We are asking people to continue to take part in clinical research for as long as possible.

I've been called up for my COVID-19 vaccine by the NHS but I am on a trial. What should I do?

Please contact the research team, who will advise. Please be patient - they may be receiving very high call volumes and it will take some time to respond to everyone individually. This is likely to include finding out whether you received an active trial vaccine or a placebo (that would offer you no protection against COVID-19), called ‘unblinding’.

You are advised not to make an appointment to receive the approved NHS COVID-19 vaccine until you have been unblinded and know that you have been given the placebo rather than the active vaccine.

Whether you are on the placebo or active vaccine trial arm, and whether you have the approved vaccine or not, please continue to attend follow-up appointments and take the advice of the research team. This will enable us to gather information to allow use of all the effective vaccines, to maximise supply and ensure that we gain a full picture of the effectiveness and use of all the vaccines available.

I’ve been unblinded and told I’ve been given the active trial vaccine. What does this mean for me?

When you are unblinded, you will be supported with further advice. If you have received the full trial dose or doses, you will be advised not to have the approved vaccine (which is the current national guidance from the independent expert group).

This is because the risks of receiving the approved vaccine after a full dose of trial vaccine are unknown and also because there is a good expectation that the active trial vaccine could protect you. As more evidence from the trial is developed, further advice may be offered to you if necessary. Please continue with the follow-up appointments.

I had the placebo vaccine, what should I do?

If you are advised that you were given the placebo and are subsequently called up for the approved COVID-19 vaccine, it is recommended that you take this up. The placebo will not give you any protection against COVID-19. Please continue to attend your trial appointments.

Can antibody tests reveal whether I received an active vaccine or placebo?

No. Antibody tests have been developed to give an idea of whether someone has had coronavirus infection (even if they had no symptoms). However many of these tests look at antibodies to parts of the coronavirus that are not contained within the vaccines. Therefore you may have had an excellent response to the vaccine and be protected from infection, but the antibody tests will be negative.

An antibody test should not be used to determine if you have had active vaccine or placebo in a trial, or to see how good a response you have had to a vaccine, as they cannot reliably provide this information.

What if I want to leave the clinical trial as a result of the vaccine roll out?

People on the trial are free to leave at any time, and this is a personal choice. However, it is important to note that leaving the trial will not offer you any further protection, as it will not affect when you can receive the approved vaccine. 

People taking part in the trial will still be able to receive an approved vaccine without delay when they are called up by the NHS. We are also only able to respond to unblinding requests at the end of the trial or for a medical reason, according to agreed protocols that set out how the trial is run. 

We ask that people continue to attend appointments, receive booster doses and share data on their health and infection with COVID for as long as possible, so that the trials can complete as early as possible.

Is it worth me joining a clinical trial now that we have approved vaccines?

It’s a personal choice but we believe it is. The approved vaccines are unlikely to be available to many people until well into 2021. There is a process in place so people on the study are not disadvantaged. 

You can still have an approved vaccine when they are available, even if you take part in a study. Taking part in a study is the best way to help effective vaccines to be identified and made available to everyone earlier, and may even give you early access to a vaccine later found to be effective.


If you have further questions about vaccine studies please visit our frequently asked questions page or visit approved vaccine studies.

You can find more information about how to get involved in other types of COVID-19 research and how it affects people in minority ethnic communities on our site.