Preliminary Data Suggests Mixing COVID-19 Vaccines Increases Frequency of Adverse Reactions

Research, from a Com-COV study comparing mixed dosing schedules of Pfizer / Oxford-AstraZeneca vaccines, shows an increase in the frequency of mild to moderate symptoms in those who received a mixed dosing schedule. The side effects were short-lived without other safety concerns. mixed schedules on immunogenicity not yet known, with data to follow from this study

Researchers conducting the University of Oxford-led Com-COV study – launched earlier this year to investigate alternating doses of the Oxford AstraZeneca vaccine and the Pfizer vaccine – today reported preliminary data showing more frequent mild to moderate reactions. reveal in mixed schedules compared to standard schedules.

Writing in a peer-reviewed Research Letter published in The Lancet, they report that, when given at four-week intervals, both caused ‘mixed’ schedules (Pfizer-BioNTech followed by Oxford-AstraZeneca and Oxford-AstraZeneca followed by Pfizer-BioNTech) more responses after the 2nd ‘boost’ dose than the standard ‘unmixed’ schedules. They add that any side effects were short-lived and there were no other safety concerns.

Matthew Snape, associate professor of pediatrics and vaccinology at the University of Oxford and lead investigator on the trial, said:

“While this is a secondary part of what we are trying to investigate with these studies, it is important that we educate people about these data, especially as these mixed dose regimens are being considered in different countries. The results of this study suggest that mixed dose schedules may result in an increase in work absenteeism the day after immunization, and this is important to consider when planning immunization for health professionals.

“Importantly, there are no safety risks or signals, and this does not tell us whether the immune response will be affected. We hope to report this data in the coming months. In the meantime, we have adapted the ongoing study to assess whether early and regular use of acetaminophen reduces the frequency of these reactions. “

They also noted that since the study data was recorded in participants aged 50 and older, there is a possibility that such reactions may be more common in younger age groups.

Reference: May 13, 2021, The Lancet.

About the Com-Cov Trial:

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

The University of Oxford is leading the study, conducted by the National Immunization Schedule Evaluation Consortium (NISEC) and supported by £ 7 million in government funding from the Vaccines Task Force.

It aims to evaluate the feasibility of using a different vaccine for the first ‘primary’ vaccination than for the follow-up vaccination ‘booster’, and helps policymakers explore whether this could be a feasible way to increase the flexibility of vaccination programs.

The study recruited 830 volunteers aged 50 and over from eight National Institute for Health Research (NIHR) supported sites in England to evaluate the four different prime and booster vaccination combinations: a first dose of the Oxford AstraZeneca vaccine followed by a boost with either the Pfizer vaccine or a further dose of the Oxford AstraZeneca vaccine, or a first dose of the Pfizer vaccine, followed by a boost with either the Oxford AstraZeneca vaccine or a further dose of Pfizer -vaccine.

In April, the researchers expanded the program to include the Moderna and Novavax vaccines in a new study (Com-Cov2) conducted at nine National Institute for Health Research-supported sites by NISEC and supported by funding from the Vaccines Taskforce and the Coalition for Epidemic Innovations in Preparedness. Volunteers would have been given either the Oxford AstraZeneca or Pfizer vaccine and then randomly assigned to either receive the same vaccine for their second dose or a dose of the COVID-19 vaccines manufactured by Moderna or Novavax.

The trial’s six new ‘arms’ were designed to recruit 175 candidates each, adding an additional 1,050 recruits to this program.

Both studies are designed as so-called ‘non-inferiority studies’ – the intention is to demonstrate that mixing is not substantially worse than no mixing – and will compare immune system responses to the gold standard responses reported in previous clinical studies of each . vaccine.

About the Oxford Vaccine Group

The Oxford Vaccine Group (OVG) conducts studies on new and improved vaccines for children and adults and is based in the Department of Pediatrics at the University of Oxford. The multidisciplinary group consists of Vaccinology Advisors, a Director of Clinical Trials, a Senior Clinical Trials Manager, adult and pediatric clinical trial staff, adult and pediatric trial nurses, project managers, statisticians, QA manager, Clinical Trials IT and Development Lead, and an administration team. The team also includes postgraduate scientists, research assistants and DPhil students and we work with professionals from a range of specialties such as immunologists, microbiologists, epidemiologists, health communicators and a sociologist, a community pediatrician, the local Health Protection team. , and a bioethicist.

OVG is a UKCRC registered clinical trial unit working in conjunction with the University’s Primary Care Trials Unit (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 country through research, and is funded by the Department of Health and Social Care. In addition to their national role, the NIHR committees applied health research to the poorest people in low- and middle-income countries, using Official Development Assistance.

About the Taskforce Vaccines

The Vaccines Task Force (VTF) is a joint unit within the Department of Business, Energy and Industrial Strategy (BEIS) and the Department of Healthcare and Social Care (DHSC). The VTF was created to ensure that the UK population has access to clinically effective and safe vaccines as quickly as possible, while working with partners to support international access to successful vaccines.

The Vaccines Taskforce consists of a dedicated team of private sector professionals and government officials working hard to build a portfolio of promising vaccine candidates who can end the global pandemic.

The UK has gained early access to 517 million doses from eight of the most promising vaccine candidates. This includes agreements with:

BioNTech / Pfizer for 100 million doses of Valneva for 100 million doses of Oxford / AstraZeneca that will work to deliver 100 million doses of the vaccine being developed by Oxford University GlaxoSmithKline and Sanofi Pasteur to purchase 60 million doses of Novavax for 60 million doses of Janssen for 30 million doses of their not-for-profit vaccine, in addition to funding their Phase 3 Moderna clinical trial for 17 million doses of CureVac for 50 million doses

The approach of the Vaccines Task Force to secure access to vaccines is through:

acquiring the rights to a wide range of promising vaccine candidates to diversify risk and optimize the chances of success, provide funding for clinical studies, diagnostic monitoring and regulatory support to rapidly evaluate vaccines for safety and efficacy, provide funding and support provide for scale-up and fill production and risk so that the UK has vaccines produced on a large scale and ready for administration should any of these prove successful

About Oxford University

Oxford University has been ranked # 1 in the Times Higher Education World University Rankings for the fifth consecutive year, and at the heart of this success is our groundbreaking research and innovation.

Oxford is world famous for its research excellence and home to some of the most talented people from around the world. Our work helps the lives of millions by solving real problems through a vast network of partnerships and collaborations. The breadth and interdisciplinary nature of our research leads to imaginative and inventive insights and solutions.

Through its research commercialization division, Oxford University Innovation, Oxford is the UK’s top university patent applicant and ranks first in the UK for university spin-outs, with more than 200 new companies created since 1988. More than one third of these companies were founded in the past three years.