UK begins world's first alternate dosing COVID-19 vaccine trial
Health chiefs in the UK on Thursday began what they have described as the world's first clinical trial of patients who will receive different COVID-19 vaccines for their first or second dose, to detect its impact on immunity against coronavirus. The study, backed by £7 million of government funding, will determine the effects of using different vaccines for the first and second doses.
Study being run by the National Immunization Schedule Evaluation Consortium
This implies, for example, using AstraZeneca's vaccine for the first dose, followed by BioNTech's vaccine for the second. Being run by the National Immunization Schedule Evaluation Consortium (NISEC) across eight National Institute for Health Research supported sites, it will gather immunological evidence on different intervals between first and second dose for mixed-vaccine regimen against control groups being given the same vaccine in both doses.
'This clinical trial will provide vital evidence on vaccine safety'
"This is a hugely important clinical trial that will provide us with more vital evidence on the safety of these vaccines when used in different ways," said Nadhim Zahawi, Minister for COVID-19 Vaccine Deployment.
'Another great step forward for British science, expertise and innovation'
"Nothing will be approved for use more widely than the study, or as part of our vaccine deployment program, until researchers and the regulator are absolutely confident the approach is safe and effective," Zahawi said. "This is another great step forward for British science, expertise, and innovation, backed by government funding - and I look forward to seeing what it produces," he said.
13-month study will monitor the impact of different dosing regimens
The 13-month study will monitor the impact of the different dosing regimens on patients' immune responses, which have the potential to be higher or lower than from the same dose regimen. Initial findings are expected to be released later in the year.
Data could support a more flexible immunization program if needed
"Given the inevitable challenges of immunizing large numbers of the population against COVID-19 and potential global supply constraints, there are definite advantages to having data," said Professor Jonathan Van-Tam, England's Deputy Chief Medical Officer and Senior Responsible Officer for the study. "The data could support a more flexible immunization program if needed and if approved by the medicines regulator," he said.
Combination of vaccines can also enhance the immune response
"It is also even possible that by combining vaccines, the immune response could be enhanced giving even higher antibody levels that last longer; unless this is evaluated in a clinical trial we just won't know," the professor said.
Over 800 patients expected to take part in the study
The study has received ethics approval from the Research Ethics Committee, as well as approval from the Medicines and Healthcare products Regulatory Agency (MHRA). Over 800 patients are expected to take part in the study, referred to as the COVID-19 Heterologous Prime Boost study or Com-Cov, across eight different sites across England - including in London, Birmingham, and Liverpool.
Vaccines used interchangeably in same schedule can increase delivery flexibility
"If we do show that these vaccines can be used interchangeably in the same schedule, this will greatly increase the flexibility of vaccine delivery," Chief Investigator Matthew Snape, Associate Professor in Paediatrics and Vaccinology at the University of Oxford said. "It could provide clues as to how to increase the breadth of protection against new virus strains," he said.
Same-dose regimen to continue in UK for now
Should the study show promising results, then the UK Government says it could consider reviewing the vaccine regimen approach, once proven to be safe and recommended by Joint Committee on Vaccination and Immunisation (JCVI). Meanwhile, the Department of Health and Social Care (DHSC) said a same-dose regimen is implemented for the UK-wide COVID-19 vaccination program, and there are no current plans to change this.
