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Vaccine trials: Getting the numbers right

Collette Healy, Delivery Support Officer from NHS DigiTrials, explains how the Permission to Contact Service supported rapid recruitment to 15 COVID-19 vaccine trials.

One of the top priorities at the start of the pandemic was to develop an effective and safe vaccine against COVID-19 as soon as was feasibly possible.

Picture shows a row of vials containing the AstraZeneca vaccine

The Government moved fast to set up a Vaccine Taskforce in April 2020 and tasked NHS Digital with delivering a service to enable members of the public to register their interest in being contacted to participate in COVID-19 vaccine clinical studies.

NHS DigiTrials offers services to support clinical trials to help reduce the time, effort and cost of developing new drugs.

I joined the DigiTrials team in July 2020 just as the Permission to Contact (PtC) service was launched – an email service to rapidly mobilise suitable volunteers.

My role is to co-ordinate large scale mailouts inviting individuals to take part in COVID-19 trials approved by the Government’s Vaccines Taskforce to enable those studies to quickly reach their necessary target numbers.

My colleagues in the DigiTrials team, our data managers and the Contact Centre staff all play a vital role in delivering this service.

Looking after the data

When we start working with a new study, I attend the introductory meetings with the research organisations and the National Institute of Health Research (NIHR) who are commissioners of the service.

We still require the research organisation to go through the Data Access Request Service (DARS) approval process even though we do not disseminate any data from the NHS Covid-19 Vaccines Registry.

This is so we can act as a Data Processor on behalf of the study. We access the data in the registry, find the required cohort and then send the invitation emails.

I help guide the research organisation through the Data Sharing Agreement and application process. A senior case officer is assigned to drive the application through the approvals process and I ensure that that officer has all the documentation they need to get sign-off.

Once the application is going through DARS approvals, I work with the NIHR to arrange all the data production requirements.

The research organisation will provide a selection criterion which the data managers then use to identify a subset of individuals in the CV-19 PtC dataset.

The data manager then extracts the names and email addresses from the dataset. During this period of data production, I work with NHS Digital’s Contact Centre to get the test email ready.

Once the Data Sharing Agreement is signed off, I validate the data is correct before sending the file to our Contact Centre.

The Contact Centre needs time to build a mailing list especially as they can be extremely large involving over 100,000 emails. It is my role to ensure all requirements are in place so that we meet the desired deadline for sending it out to the invitees.

Our challenges

There have been many challenges along the way as the service was developed at pace.

Just as we were completing the application approval and getting ready to help support recruitment for the first trial (AsraZeneca/Oxford), the delivery model that we had planned to use for all trials changed at the very last minute.

We had initially planned to send a data file to Oxford for them to reach out to contact people on the registry. However, NHS Digital took on the responsibility for sending out the invitation emails when it transpired that Oxford did not have the capacity to do this themselves.

Thousands of emails were rejected or bounced back to us as the recipients' firewalls recognised we were using a spoofed address.

My team and I worked with the Contact Centre to design a new model to support the service. It became clear that all the other studies wanted us to support them in this way.

We tried to make the first invite emails look as though they were sent directly by the research organisation. To do this we created an email account for the study that had the contact centre email address hidden behind it but this caused major issues.

Thousands of emails were rejected or bounced back to us as the recipients’ firewalls recognised we were using a spoofed address.

We reverted back to using the Contact Centre email address but they were inundated with queries from participants and we didn’t have the resources to respond to all of them.

We therefore designed a unique workflow applied to all replies that we receive. This advises we are unable to respond in person and provides responses to common FAQs and links that could provide more useful information for people.

Another challenge we faced in the early days of delivering the service was all studies quite often made last minute changes to their mailout requirements. We were regularly asked to get data ready for additional sites that we were not expecting to be included in the mailing or we would be asked to remove data for certain sites as they were not ready.

This caused us a lot of stress as it meant the data file and mailing list had to be deleted and rebuilt in very short timescales to meet the mailing list deadline.

Study sites are located across the country predominately based within a hospital, for example the Cov-Boost Study has a site based at St James Hospital in Leeds. Sites quite often would advise they were unable to be involved initially due to issues such as unsigned contracts, vaccine supplies not received or insufficient staff.

Equally Sites that we thought were not going to be included initially would resolve outstanding issues quicker than expected and at the very last minute advise they were to be included in the mailout.

This caused us a lot of stress as it meant the data file and mailing list had to be deleted and rebuilt in very short timescales to meet the mailing list deadline. This is because initially the data was prepared in one job for all the sites.

To work around this problem, we developed a spreadsheet that collated all the requirements of the study sites.

The data was then prepared separately for each site. When we have confirmation which sites are ready, all the relevant data files are then put into one file to be sent to the contact centre to build a mailing list.

When big projects clash

The DigiTrials team support the delivery of the monthly Vaccine Registry newsletter which is sent to participants who have consented to receive it. We currently send up to half a million newsletter emails each month.

Not only do the newsletters recognise the value of the participants’ roles in the trial, they also reinforce messages given at briefings given by senior Government ministers and senior health officials.

We often have to change the timing of the emailings to fit around briefings and just before Christmas we had to change one mailing 3 times to fit around an announcement by the Prime Minister.

I work closely with NIHR to proof read, sense check, ensure sign-off and negotiate a date that enables the Contact Centre to prepare and send it out at the right time.

There has been many occasions when the newsletter mailing has clashed with a COVID-19 recruitment mailing. It is down to the dedication and hard work of the Data Manager involved and the Contact Centre that these mailings have gone out in good time.

Key achievements

  • over 700,000 invitations have been sent to volunteers
  • 516,000 volunteers signed up to the registry – exceeding our 500,000 target
  • we’ve supported the recruitment to 15 COVID-19 studies – 3 of which have developed vaccines that were then approved for the general population

Novavax Trial completed recruitment for their whole study in less than 2 months. This was an unprecedented timeframe for completing recruitment into a trial for which we supported by sending over 72,0000 invitations.

Supporting the study into the booster vaccine

Last summer our team supported the recruitment to a study looking at the use of Moderna, Pfizer and AstraZeneca Oxford vaccines as a third booster vaccine.

Over a 4-week period we sent 37,743 emails to support recruitment to the study. The booster campaign is successful due to this groundwork for the study. The trial found that Covid booster shots significantly strengthen immunity.

Lessons learnt

I personally feel very proud to have worked with such a great team who been able to support the various vaccine studies and help them meet their recruitment targets by doing whatever was necessary such as working late and out of hours to ensure deadlines were met.

This work has led to the successful recruitment of many studies, 3 of which have been able to develop approved Covid 19 vaccines - saving thousands of lives across the UK.

As a result of the success of the vaccines registry this has led to further thinking and work about how we can harness the enthusiasm of those who volunteered to consider further opportunities to be involved in research. 

Colleagues in my team have recently completed a review with all key stakeholders involved in the development and execution of the NHS Vaccines Registry. This discovery piece will feed into a wider project looking at the possibility of having a more generalised registry for wider clinical research.

Related subjects

Andy Rees, Clinical Trials Operations Manager for NHS DigiTrials, explains how routine NHS data has supported the fastest ever recruitment to a large-scale randomised trial - and explores what the new service means for clinical research in the UK.


Last edited: 10 October 2022 11:30 am