Com-COV alternating vaccine schedule study for 12-to-16-year-olds launches in south London

Researchers in south London are to begin running the latest University of Oxford-led Com-COV study, looking into different COVID-19 vaccination schedules for young people aged 12 to 16.

Running at St George’s University Hospitals NHS Foundation Trust, the Com-COV 3 trial will seek to recruit 360 volunteers nationally. The study is backed through funding from the Vaccines Taskforce and National Institute for Health Research (NIHR) and by the National Immunisation Schedule Evaluation Consortium.

Participants can either receive two COVID-19 vaccine doses in the study, in which case their first dose will be the Pfizer COVID-19 vaccine. Alternatively, those who have already received a dose of the Pfizer COVID-19 vaccine through the NHS can be enrolled at the time of their second dose.

All participants will be randomly allocated at the time of the second dose to receive either a full dose or half dose of the Pfizer-BioNTech vaccine, a full dose of the Novavax vaccine or a half dose of the Moderna vaccine.

The study is single-blind and randomised, meaning participants will not know what second dose vaccine they are receiving. Researchers will assess reactogenicity (any side effects) and immune system responses to these different vaccine combinations.

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

“This study will provide vital information on the range of options for immunising teenagers against COVID-19 in the UK.

“As well as looking at the standard two full doses of the Pfizer vaccine, we will look at how well volunteers respond when their second dose of Pfizer is half that of the first dose, or if different vaccines are used altogether, such as the vaccines manufactured by Moderna or Novavax. This will provide the JCVI with information crucial to informing their advice about immunising teenagers in the UK.

“This is the latest in a series of studies such as Com-COV and COV-BOOST that have looked at ways the different COVID-19 vaccines available in the UK can be used to generate the best and most durable immune response, in as safe a manner as possible.”

Professor Andrew Ustianowski, NIHR Clinical Lead for COVID-19 Vaccination Programme and Joint National Infection Specialty Lead, said:

“It is important to establish the most effective vaccine doses for different population groups, and this latest study will help develop our understanding of immune responses for young people once vaccinated against COVID-19.

"We continue to see valuable contributions from volunteers across COVID-19 vaccine research across the UK to help us identify the best vaccine schedules, and I hope we see similar levels of engagement with the Com-Cov 3 study.”

Professor Paul Heath, Professor of Paediatric Infectious Diseases at St George’s, University of London and Principal Investigator for the Com-Cov 3 study at St George’s Hospital, said:

“We need to find out which of several different COVID-19 vaccines are best to provide sufficient immunity when given as a second dose to young people aged 12 and above. The Com-Cov 3 study will provide vital evidence that will help us identify the best vaccine schedules for protecting the next generation against this disease.”

The study hopes to report initial results by December – if the results are promising, regulators MHRA and JCVI would formally assess the safety and efficacy of any new vaccination process before advising whether it is rolled out to patients.

Those who are interested can register via the study website https://comcovstudy.org.uk