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There is a compelling case for rolling out COVID-19 booster vaccines for some people with weakened immune systems to help optimize antibodies against SARS-CoV-2, the scientists said.
The comments followed the results of a study that suggested that a significant proportion of clinically at-risk patients with certain immunocompromised or immunocompromised conditions exhibit a weak or undetectable antibody immune response after two doses of a COVID vaccine.
Initial data from the Observational Cohort Trial-T-cells Antibodies and Vaccine Efficacy in SARS-CoV-2 (OCTAVE) study were reported today in a pre-publication.
This suggests that about 60% of patients in the study groups developed an immune response that resembled that seen in healthy control subjects. However, around 40% had a weak or undetectable immune response.
The research, a UK-wide, multi-center trial led by the University of Glasgow and coordinated by the UK Cancer Research Clinical Trials Unit at the University of Birmingham, aimed to assess immune responses after COVID vaccination in immunocompromised people. mediated by inflammatory and chronic diseases. These included inflammatory arthritis, kidney or liver disease, cancer, and patients undergoing stem cell transplants.
Preliminary results
The first data, based on about 600 participants from a much larger cohort, was compared to that of 231 healthy people in the PITCH (Protective T Cell Immunity in Healthcare Workers) study.
The researchers report that although all individuals tested in the PITCH study generated antibodies against the SARS-CoV-2 spike protein after two doses of the Pfizer / BioNTech or AstraZeneca / Oxford vaccine, only 89% of patients within of OCTAVE were seroconverted 4 weeks after a second dose.
Antibody levels depended on the disease of the patients. The percentage of patients responding less well than the lowest levels seen in healthy subjects was highest in those with:
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Patients with ANCA-associated vasculitis treated with rituximab (87%)
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Inflammatory arthritis (51%)
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Renal failure on hemodialysis and immunosuppressants (42%)
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Liver disease (36%)
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Renal failure on hemodialysis (20.3%)
The lowest rates of patients with poor antibody reactivity were seen in patients with solid cancer (10%) and those who had hematopoietic stem cell transplants (17%).
Prof Iain McInnes / SMC
Professor Iain McInnes, deputy director of the University of Glasgow, who led the study, said in a briefing hosted by the Science Media Center: “The majority of patients in the OCTAVE trial actually developed an immune response that looks remarkably like a healthy control group. “
In addition, their results were compared to an “optimal group” made up of people who were, on average, younger than the OCTAVE cohort.
He also pointed out that even patients who showed no antibody response after vaccination could be protected by a T cell response.
“We’re pretty reassured that even patients on sizeable immunosuppressive regimens develop this cellular response, this T-cell response, and it gives us optimism that there is indeed a degree of protection against viruses, even for those whose antibody levels may be negative. “
Booster vaccine study
When asked if patients with weakened immune systems might benefit from a booster vaccine, Prof McInnes said: “Our data suggests that a booster for people who have developed an absent level of antibody response or less would be a very reasonable next step. “
Researchers had already started a separate trial, called OCTAVE DUO, to answer this question, he said.
These would be patients randomized to receive the Pfizer or Moderna vaccine, a small subgroup receiving a third booster dose with the Novavax vaccine.
‘Depth study’
Commenting, Dr Doug Brown, chief executive of the British Society for Immunology, described the paper as “one of the most comprehensive studies to date” on the subject.
He said: “As we find our way out of the pandemic, we must continue to research how to optimize COVID vaccination schedules for patients with weakened immune systems in order to maximize the future protection of these people.
“This includes examining the usefulness of booster doses and researching other treatment options for the small minority of patients unable to generate an immune response after vaccination.”
Eleanor Riley, professor of immunology and infectious diseases at the University of Edinburgh, said research has shown that many patients in the OCTAVE trial “produced a detectable antibody response and their response again increased after the second dose of vaccine “. So it was “quite possible that they reacted even better after a third dose of the vaccine,” she said.
Examining the Immunologic Effects of COVID-19 Vaccination in Patients with Conditions That May Cause Impaired Immune Response Capacity – The OCTAVE Trial, Pre-publication
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