COVID-19 vaccine studies frequently asked questions

Vaccine Passports/certification, boosters and travel

The latest information and FAQS on this issue can be found on the Latest Vaccine News page, which is updated regularly.


If you take part in a vaccine study, you may be given either the study vaccine or an already approved vaccine (also known as the control arm of the study). All study vaccines are tested to make sure they are safe, before being tested in people.

You'll need to visit the hospital, or other research site, a few times over 6 to 12 months.

At these visits, you should:

  • be told about the research study
  • have the chance to ask any questions
  • have blood tests

Between visits, you'll be asked to tell the research team about any symptoms you have. You may also be asked to self-monitor at home, for example by doing swabs or keeping an e-diary. There are many different types of research taking place to tackle COVID-19. Here's how to get involved.

Yes. Taking part in a study is the best way to help more effective vaccines to be identified and made available earlier, and may even give you earlier access to protection.

We still need further research into several vaccines, to look at how best to protect communities and the population as a whole. Studies are underway looking into:

  • new vaccines, so that there are enough vaccines to protect everyone globally
  • certain groups such as pregnant women, children and young adults, and those with a weakened immune system
  • how best to use existing vaccines, different vaccine dose sizes, the interval between doses, and whether the brand/type of vaccine given at different doses makes a difference to effectiveness
  • booster vaccines or additional doses
  • vaccines against new variants of COVID-19

All of the currently MHRA approved COVID-19 vaccines being given in the UK are vegetarian, and do not contain any egg or animal products, meaning they are also halal and kosher friendly. You can find out more about the ingredients of these vaccines by using the links below:

There are a number of different vaccines in development within the UK. It is expected that these will also be vegetarian or vegan, and as and when they are approved and deployed in the NHS, individual details will be shared on individual vaccines. The ingredients of each of these vaccines will be accessible in the Participant Information Sheet paperwork.

In England, the research partner of the NHS is the National Institute for Health and Care Research (NIHR). If you sign up to be contacted about vaccine studies, only researchers on studies supported by NIHR - and who have applied to use the service and been approved - will be able to contact you. You can view a list of approved NIHR supported COVID-19 vaccine studies.

When researchers from an approved study contact you, the first email will be from an official email address. On the approved vaccine studies page, you can select an approved study to find out the official email address that you will receive an email from if you match its criteria. Check this list to ensure the email you receive notifying you that you may be eligible for a study is legitimate.

If you are interested in a study you receive an official email about and decide to get in touch with the study team, and/or complete the online screening form as directed in the email, the study team will be in touch with you directly. 

Researchers will never ask you for money or passwords. Always be alert to the risks of clicking on links or attachments. You can learn more about how to protect yourself from scam emails on the Action Fraud website.

Check back on Be Part of Research or contact the team if you are worried that an email may not be legitimate. Contact from researchers will be from one of the following email addresses:; or

If you enrol in a vaccine study, the research team will collect information as part of that particular study. This information is held by the research team and any information that is collected about you will be kept confidential, in the same way as your medical records.

  • If your doctor or consultant is not the person who approached you about the study, it can be helpful for them to be told you are taking part in a study as they will be responsible for your day-to-day healthcare; but they can only be told with your permission.

  • Once the study has finished the results are usually published, and often presented at conferences. No name or any information that can identify you will be used in this presentation or any reports about the study.


The safety of volunteers is our highest priority. All medicines that we take, and all vaccines that we give, carry risks. The whole purpose of research is to minimise those risks. As with any medicine, vaccines are highly regulated products. There are checks in place at every stage in the development of a vaccine and that is not being compromised.

The Medicines and Healthcare products Regulatory Agency (MHRA), a globally leading regulatory agency, checks the safety, quality and effectiveness of all COVID-19 vaccines, and ensures no stage in the development process is skipped. Volunteers are carefully assessed before they take part, and are carefully monitored afterwards, with 24 / 7 access to doctors and nurses running the trial. This is so they can report anything they are concerned about or if they feel unwell for any reason.

We’re researching different types of vaccines against COVID-19. Some of these types of vaccines have been in use for a long time. This means we have a lot of experience and data on how they work, the immune responses they generate, and knowledge about their safety. In any trial, it isn’t the research that takes a long time, it’s the steps beforehand: for example funding and approvals. What has been sped up in the process this time is the funding, not the actual undertaking of the studies. Each trial has an independent safety committee that keeps the study under active review, including any reports of side effects. They can take immediate action such as suspending the trial, if any problems are found.

This short animation helps to explain how vaccines for COVID-19 have been developed in a short space of time.

Please sign up to register your interest. Researchers look for lots of different people to take part in their studies to make sure it works for everyone. A number of studies will be looking for healthy people with no pre-existing conditions. Some studies may be looking specifically for people of different ages with an existing condition or a suppressed immune system, as they may respond differently to a vaccine. In some studies, there will be certain people who cannot be enrolled at this time, such as people who are being treated for cancer, who are pregnant or breastfeeding, or who have certain immune conditions. However, there are certain studies looking at people in these specific groups.

Registering with NHS COVID-19 Vaccine Research Registry allows researchers to contact you. When they do, they will discuss any pre-existing medical conditions you may have. You may also want to speak to your own health professional for further advice.

Vaccines are tested in a number of stages to make sure they are both safe and effective. You may be invited to participate in a study that is evaluating whether the vaccine is safe to be used for other people like you.  

The information you are given about any study you are invited to take part in will explain what stage the vaccine is at and how it has already been tested. You can consider this information when deciding whether to take part.

Common vaccine side effects include soreness, swelling and redness at the site of the vaccination and sometimes more general symptoms like tiredness, achy muscles and fever may last for a few days and get better by themselves. The study team will give you further information about common side effects and how to manage them, and what to do if you experience any other side effects.

Taking part in human challenge trials is voluntary. In these trials, a few young, healthy volunteers may be exposed to small amounts of live virus after vaccination. Volunteers for any clinical trials only take part with their full consent, and all the facts of the trials are made available to them before they sign up. This ensures that volunteers do so with full knowledge of the facts and clinical risks.

New coronavirus variants continue to emerge, and most of the original large clinical trials were not designed to capture data on how vaccines protect against all new variants. However, there are other studies going on, including laboratory tests and looking at ‘real world’ data, that is, information on people who become ill with different variants of COVID and which (if any) vaccines they received. There have been several publications from a range of vaccines evaluating their effectiveness against new variants, showing they still offer protection to varying levels.

There are a number of UK based vaccine studies running which are looking into how effective boosters are against the original and latest variants, as well as using vaccines which specifically target a certain variant.


Yes, we encourage everyone to take up the offer of a flu vaccine as soon as it is offered to you.

Some vaccine studies will ask that you do not donate blood for the duration of the study.

This will depend on the individual study. This is because you may have some immunity that means you are less likely to contract COVID, with or without a vaccine, and could sway the research findings. You can still sign up to take part in COVID and other healthcare research though. There are many other trials underway that you may be suitable for, including some on the long-term after effects on having had COVID.

Find out how to get involved in other COVID-19 research.

Please also come forward for an approved COVID vaccine when you are invited to, as long as it is 28 days since your positive COVID test.