JCVI issues advice on third dose COVID-19 vaccination for severely immunosuppressed

JCVI issues advice on third dose COVID-19 vaccination for severely immunosuppressed

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

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. These people may not mount a full response to vaccination and therefore may be less protected than the wider population.

The offer is separate to any potential booster programme, whilst the JCVI still deliberates the potential benefits of booster vaccines for the rest of the population and awaits further evidence.

Preliminary data from the OCTAVE trial showed that almost everyone who was immunosuppressed mounted an immune response after 2 doses, as indicated by either antibodies or T cells. However, in around 40% of people, the levels of antibodies were low. It is not clear how much this may affect protection against COVID-19 as antibodies represent only part of a person’s immune response.

The JCVI advises that for adults aged 18 and older, either the Moderna or Pfizer-BioNTech COVID-19 vaccines be administered for the third dose, as a number of studies have reported an increased immune response in some immunosuppressed people after a third dose of an mRNA vaccine. For those aged 12 to 17, the Pfizer-BioNTech vaccine is preferred.

As a general guide, the third dose should usually be at least 8 weeks after the second dose but with flexibility to adjust the timing so that, where possible, immunosuppression is at a minimum when the vaccine dose is given. This will enable a better immune response to be generated. For example, it is preferable to give a vaccine dose before someone undergoes chemotherapy, rather than during their treatment.

Those with less serious immunosuppression are not included in this advice but are likely to become eligible for another dose as part of a potential booster programme, pending further advice from the JCVI. In the event of a booster programme, it is expected that severely immunosuppressed people will also be offered a booster dose, at a suitable interval after their third dose.

A third primary dose is an extra ‘top-up’ dose for those who may not have generated a full immune response to the first 2 doses. In contrast, a booster dose is a later dose to extend the duration of protection from the primary course of vaccinations.

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.”