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COVID-19 vaccine booster study targets Omicron variant

Volunteers are needed for a study looking at the use of COVID-19 vaccine that targets the Omicron variant when given as a fourth dose.

The COV-BOOST sub-study, sponsored by University Hospital Southampton NHS Foundation Trust, is recruiting in 10 locations across the UK.

The research is assessing the safety and effectiveness of Pfizer and Moderna vaccines. Results from the trial will make a valuable contribution to the pandemic response.

You may be eligible to take part if you:

• Are aged 30 years old or above

• Received BNT162b2 (Pfizer) or mRNA-1273 (Moderna) as your third dose booster at least three months (84 days) ago

• Have not previously tested positive for COVID-19 on a PCR, lateral flow test, or saliva test

Volunteers will be provided reimbursement up to £225 for time, inconvenience and travel. The total study participation time is up to eight months.

Options for fourth dose

Omicron is now the most common variant of COVID-19 in the UK. Mutations on its spike protein make it more capable of evading the immune response generated by existing vaccines than previous variants.

Two doses are thought to provide very little protection against infection, although they do provide good protection against severe disease. Three doses provide much improved protection against infection and severe disease or death. However, this protection wanes over a period of months following vaccination.

The pharmaceutical company Moderna has adapted its COVID-19 vaccine to produce a version of the spike protein that more closely resembles the one found on Omicron.

The new study will evaluate the Pfizer and revised Moderna vaccines when given as a fourth dose COVID-19 booster.

Informing the UK’s booster programme

The wider COV-BOOST study published its full initial results in the Lancet in December 2021. These found several COVID-19 vaccines were safe and boosted immunity and its early findings in September 2021 informed the UK’s booster programme.

Anyone interested in finding out more or taking part in the latest sub-study can visit the COV-BOOST website, where they can complete the study questionnaire to see if they are eligible.

This study has been approved by South Central – Berkshire Research Ethics Committee.

If you would like any further information, please contact us on:


Tel: 023 8120 4989

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