New study to test third COVID-19 vaccine for people with weakened immune systems.

Posted on: 26th August 2021

A new clinical trial to determine whether a third dose of vaccine will improve the immune response for people who have weakened immune systems is launching in the UK.

The study, called OCTAVE DUO, will offer people who are immunosuppressed or immunocompromised a Pfizer, Moderna or Novavax vaccine to determine whether this will give a stronger immune response than two doses.

The £2.2 million study will build on the OCTAVE trial, led by the University of Glasgow and co-ordinated by the University of Birmingham’s Cancer Research UK Clinical Trials Unit.

What were the results of the OCTAVE study?

The OCTAVE trial has published preliminary data today showing that 89% of people who are immunocompromised or immunosuppressed generate antibodies following vaccination, and 60% generated a strong antibody response following two doses of a vaccine.

However, 40% of people in these groups mounted a low, or undetectable, immune response after two doses, and the level of antibody response varies between the groups studied.

The level of antibodies required for protection from COVID-19 is still not known, and it is likely that T cells also play an important role in protecting people from the virus. These findings therefore don’t provide a conclusive assessment of the protection vaccines offer people with weakened immune systems.

Rebecca West, Liver Nurse Manager at the British Liver Trust, says: “Some liver patients who are immunocompromised or immunosuppressed are understandably worried about how effective the vaccine is for them, and it’s still really important people in this group continue to take measures such as hand washing and social distancing to keep them safe.

“However, the fact that 89% of people in this group did generate some antibodies is encouraging so we continue to recommend that everyone living with liver disease has both doses of the COVID-19 vaccine to give them as much protection as possible from the virus.”

About the OCTAVE DUO study

Up to 1,200 patients who are already involved in the OCTAVE study or those with other at-risk conditions involved in parallel studies will be recruited to the OCTAVE DUO trial.

The OCTAVE DUO study, co-funded by the government’s Vaccines Taskforce and UK Research and Innovation (UKRI) and led by the University of Glasgow and University of Birmingham, will analyse in detail the immune response of this group to the vaccine and the durability of this protection. It will also use healthcare records to determine whether any participants are later diagnosed with COVID-19.

Patients included in the study are people with liver and intestinal disease, lymphoid malignancies, immune mediated inflammatory diseases (including rheumatoid arthritis, psoriatic arthritis, vasculitis and inflammatory bowel disease), renal disease, solid tumours (including breast and lung cancers), haematopoietic stem-cell transplantation, and primary immune deficiency.

Initial results are expected later this year to inform the UK’s COVID-19 vaccine deployment in these specific at-risk groups. The trial will follow the patients to mid-2022 and offer more detailed information at that stage about the immune responses that develop in these groups.

The government is carefully considering the findings of the OCTAVE trial and will also consider any further appropriate advice – including from the independent Joint Committee on Vaccination and Immunisation (JCVI) - for those who are immunosuppressed as part of regular reviews of the latest data and evidence on vaccine efficacy and effectiveness.

What have other studies shown?

A separate study by Public Health England in July which looked at antibody response and vaccine effectiveness against symptomatic infection also showed that those who were immunocompromised had lower antibody responses.

It also found that protection from COVID (vaccine effectiveness against symptomatic disease) for those who are immunosuppressed of all ages after one dose was 4%, but after two doses it was 74%, providing similar protection to those who are not in an at-risk group. Again, vaccine effectiveness may vary by specific condition and severity of that condition.

Background on the vaccination programme

  • The latest UK-wide vaccination statistics are published here and NHS England publishes vaccine statistics for England here.
  • The latest PHE analysis on the efficacy of COVID-19 vaccines is available here. Their latest study on the number of cases prevented and lives saved by vaccines is here.
  • PHE have published data on the effectiveness of COVID-19 vaccines for at-risk groups here.
  • Visit the NHS website for advice on how to book or manage a COVID-19 vaccination appointments.