The Joint Committee on Vaccination and Immunisation (JCVI) has advised that people with severely weakened immune systems should have a third vaccine dose as part of their primary COVID-19 vaccination schedule.

According to the JCVI, this third dose should be offered to people over 12 who were severely immunosuppressed at the time of their first or second dose, including those with leukaemia, advanced HIV and recent organ transplants.

The decision is based on preliminary data from the OCTAVE trial, which showed that while almost everyone who was immunosuppressed mounted an immune response after 2 doses, in around 40% of people, the levels of antibodies were low.

The JCVI is awaiting further evidence to inform a decision on a potential booster programme for those with less serious immunosuppression.

Professor Wei Shen Lim, chair of COVID-19 immunisation for the JCVI, said: “We want people with severely suppressed immune systems to have the best chance of gaining protection from COVID-19 via vaccination. Therefore, we are advising they have a third vaccine dose on top of their initial two doses, as we hope this will reduce their risk of severe outcomes such as hospitalisation and death.”