Fourth COVID-19 vaccine dose provides good immunity, Oxford-backed study finds
COVID-19 vaccines given as fourth doses in the UK offer a strong immunity boost, according to the latest results from a nationwide NIHR-supported study.
The latest results from the COV-BOOST trial, run at UK sites including Oxford Vaccine Group, show a fourth dose is safe and boosts antibody levels higher than a third dose.
Fourth doses of COVID-19 vaccines have been offered as a spring booster for those most vulnerable in the UK as a precautionary strategy to maintain high immunity levels prior to study data being available. More may be offered a fourth dose later this year.
The trial - published in The Lancet Infectious Diseases - found fourth doses are well-tolerated in those who received the Pfizer vaccine as a third dose and increased antibody and cellular immunity above that from third doses.
The COV-BOOST study, led by University Hospital Southampton, initially provided the world’s first data on the safety, immune responses and side-effects of a third dose in mix and match schedules. These results were key to shaping the UK’s autumn booster programme and gives vital evidence for global vaccination efforts.
In the fourth dose study, 166 volunteers who had a third dose of Pfizer, following Pfizer or AstraZeneca initial doses in June 2021, were randomised to receive full dose Pfizer or half dose Moderna vaccine as a fourth dose seven months after third doses.
Dr Angela Minassian, study Principal Investigator at the Oxford Vaccine Group, said: “The results support the safety of this approach and the benefit of a fourth dose in boosting the immune response against COVID-19, of most importance to those who are vulnerable.
“I would like to thank our participants for continuing on this COV-BOOST journey with us and to the ongoing efforts of the incredible team at the Oxford Vaccine Group.”
Professor Lucy Chappell, Chief Scientific Adviser for the Department of Health and Social Care and NIHR Chief Executive said: “These results show the benefits of having a fourth COVID-19 booster dose for those eligible to top-up immunity.
“It is important to recognise the achievement of the COV-Boost study team, participants and all involved who have helped deliver this research to inform the best use of COVID-19 booster vaccines in the UK.
“The COV-Boost study, commissioned through the NIHR, is continuing to deliver world-leading research on booster vaccination.”
Current COV-BOOST sub-studies are investigating the interval between second and third doses, fourth doses of mRNA vaccines, an omicron variant vaccine and half-doses in ages 18-30.
Read more on the NIHR website.
