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Alternating Covid-19 vaccine dose study launches in Birmingham

Researchers running the Com-Cov study investigating alternating doses of the Oxford-AstraZeneca vaccine and the Pfizer vaccine, have announced a new study in Birmingham now including the Moderna and Novavax vaccines.

The additional study will seek to recruit adults aged over 50 who have received their first, or ‘prime’ vaccination in the past 8-12 weeks, and will be run at University Hospitals Birmingham NHS Foundation Trust (UHB). Led by the University of Oxford, the study will be run by the National Immunisation Schedule Evaluation Consortium (NISEC) across nine National Institute for Health Research (NIHR) supported sites. It is backed through funding from the Vaccines Taskforce and the Coalition for Epidemic Preparedness Innovations.

Study participants, who will have already received either the Oxford-AstraZeneca, or Pfizer vaccine, will be randomly allocated to receive either the same vaccine for their second dose, or a dose of the COVID-19 vaccines produced by Moderna or Novavax.

The six new ‘arms’ of the trial will each recruit 175 candidates, adding a further 1050 recruits into the Com-Cov programme.

Working across nine sites in the UK, the researchers will study reactogenicity (any adverse reactions) and the immune system responses to these new combinations of vaccines. The study is designed as a so-called ‘non-inferiority’ study and will compare the immune system responses to the gold-standard responses reported in previous clinical trials of each vaccine.

If the study shows promising results, the regulators MHRA and JCVI would formally assess the safety and efficacy of any new vaccination regimen before it would be rolled out to patients.

Matthew Snape, Associate Professor in Paediatrics and Vaccinology at the University of Oxford, and Chief Investigator on the trial said:

“The focus of both this and the original COM-COV study is to explore whether the multiple COVID-19 vaccines that are available can be used more flexibly, with different vaccines being used for the first and second dose.

“If we can show that these mixed schedules generate an immune response that is as good as the standard schedules, and without a significant increase in the vaccine reactions, this will potentially allow more people to complete their COVID-19 immunisation course more rapidly. This would also create resilience within the system in the event of a shortfall in availability of any of the vaccines in use.”

Dr Chris Green Consultant In Infectious Diseases at UHB says: ‘Clinical studies into COVID-19 vaccines remain critical to help find several safe and effective candidates to help protect us all. Studies such as Com-Cov2 can help us learn more about the flexibility of COVID-19 vaccine schedules. Volunteers in the West Midlands are still needed to help carry out these studies. Visit to sign up to be contacted about taking part in COVID-19 vaccine research.’


Notes to Editors:
For more information locally, contact the NIHR LCRN Communications Lead Claire Hall -

For media requests with the researchers from the University of Oxford, please contact:

About the Com-Cov trial:

There are expected to be 1050 volunteers across nine different sites in the trial, including:

St George's University Hospitals NHS Foundation Trust
University Hospitals Birmingham NHS Foundation Trust
The University of Nottingham Health Service
Liverpool School of Tropical Medicine
University College London Hospitals NHS Foundation Trust
Hull University Teaching Hospitals NHS Trust
The Newcastle Upon Tyne Hospitals NHS Foundation Trust
Guy's and St Thomas' NHS Foundation Trust
Sheffield Teaching Hospitals NHS Foundation Trust

The study has been classified as an Urgent Public Health study by the NIHR and is being undertaken by NISEC and the Oxford Vaccine Group, with funding of £7 million from the government through the Vaccines Taskforce.

Volunteers interested in signing up to COVID-19 vaccine studies can find out more and register their interest here:

About the Oxford Vaccine Group
The Oxford Vaccine Group (OVG) conducts studies of new and improved vaccines for children and adults and is based in the Department of Paediatrics at the University of Oxford.

The multidisciplinary group includes consultants in vaccinology, a Director of Clinical Trials, a Senior Clinical Trials Manager, adult and paediatric clinical research fellows, adult and paediatric research nurses, project managers, statisticians, QA manager, Clinical Trials IT and Development Lead, and an administration team. The team also includes post-doctoral scientists, research assistants and DPhil students and we work together with professionals from a range of specialities such as immunologists, microbiologists, epidemiologists, health communicators, and a sociologist, a community paediatrician, the local Health Protection team and a bioethicist.

OVG is a UKCRC registered clinical trials unit working in collaboration with the Primary Care Trials Unit at the University (registration number: 52).

About the National Institute for Health Research
The National Institute for Health Research (NIHR) is the nation's largest funder of health and care research. The NIHR was established in 2006 to improve the health and wealth of the nation through research, and is funded by the Department of Health and Social Care. In addition to its national role, the NIHR commissions applied health research to benefit the poorest people in low- and middle-income countries, using Official Development Assistance funding.

About the Vaccines Taskforce

The Vaccines Taskforce (VTF) is a joint unit in the Department for Business, Energy and Industrial Strategy (BEIS) and Department for Health and Social Care (DHSC). The VTF was set up to ensure that the UK population has access to clinically effective and safe vaccines as soon as possible, while working with partners to support international access to successful vaccines.

The Vaccines Taskforce comprises a dedicated team of private sector industry professionals and officials from across government who are working at speed to build a portfolio of promising vaccine candidates that can end the global pandemic.

The UK government has secured early access to 457 million vaccines doses through agreements with eight separate vaccine developers. This includes agreements with:

​- BioNTech/Pfizer for 40 million doses
- Valneva for 100 million doses
- Oxford/AstraZeneca for 100 million doses
- GlaxoSmithKline and Sanofi Pasteur for 60 million doses
- Novavax for 60 million doses
- Janssen for 30 million doses
- Moderna ​for 17 million doses
- CureVac ​for 50 million doses

The Vaccines Taskforce’s approach to securing access to vaccines is through:

- procuring the rights to a diverse range of promising vaccine candidates to spread risk and optimise chances for success
- providing funding for clinical studies, diagnostic monitoring and regulatory support to rapidly evaluate vaccines for safety and efficacy
- providing funding and support for manufacturing scale-up and fill and finish at risk so that the UK has vaccines produced at scale and ready for administration should any of these prove successful

About the University of Oxford

Oxford University has been placed number 1 in the Times Higher Education World University Rankings for the fifth year running, and at the heart of this success is our ground-breaking research and innovation.

Oxford is world-famous for research excellence and home to some of the most talented people from across the globe. Our work helps the lives of millions, solving real-world problems through a huge network of partnerships and collaborations. The breadth and interdisciplinary nature of our research sparks imaginative and inventive insights and solutions.

Through its research commercialisation arm, Oxford University Innovation, Oxford is the highest university patent filer in the UK and is ranked first in the UK for university spinouts, having created more than 200 new companies since 1988. Over a third of these companies have been created in the past three years.