Findings of study into vaccine effectiveness in the immunocompromised released

New research has found that one in 10 people with some solid cancer tumours respond less well to the COVID-19 vaccine than healthy people.

The findings are from the OCTAVE trial, a large study looking at the effectiveness of COVID vaccines in people who have a weakened immune system ('immunocompromised') due to a range of medical conditions, including cancer. The study looked in detail at blood samples from 600 immunocompromised people in the UK, taken before and/or after COVID-19 vaccinations.

The researchers found that four in ten people who are immunocompromised produced fewer antibodies than expected against COVID after two doses of vaccine, while 11% of people did not have any antibodies against COVID four weeks after two vaccines. One in ten people with a solid cancer tumour (breast and lung) responded less well to the vaccines than the lowest levels seen in healthy patients.

However the significance of this research in terms of what they can tell us about vaccine protection from exposure to COVID-19 is not currently known, as there is no current agreed measure of what an 'optimal' COVID-19 vaccination response looks like. Further research is needed to better understand the levels of immune response which will provide protection against COVID-19.

An extension of the OCTAVE study will now look at whether a third dose of a COVID-19 vaccine for people with weakened immune systems, including those with cancer, gives a stronger immune response than two doses.

Genevieve Edwards, Chief Executive of Bowel Cancer UK, says: "Although it's hugely frustrating that bowel cancer patients were not included in this study, the results do at least give us some insights to the likely immune response of people with solid tumours to the COVID vaccines. We're pleased that the findings are being used to inform decisions regarding the booster vaccine programme for all immunocompromised patients, which will be starting in September.

"We know that this news may be worrying for people affected by bowel cancer. We would encourage everyone to make sure they receive their vaccine doses if they haven't done so already, and take up the booster vaccination when offered."

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