Some patients with compromised immune systems failed to generate antibodies against Covid-19
New research has added weight to calls for a 冠状病毒病-19 vaccine booster programme in the UK this autumn after some patients failed to produce antibodies against the virus.
The new study examined the ability of 600 patients whose immune system was compromised, either by diseases such as cancer or because of medical treatment, to respond to the vaccines.
虽然 60 per cent generated antibodies, 40 per cent had a markedly lower level with 11 per cent failing to make any antibodies at all four weeks after having two vaccine doses.
The results come as the government’s Joint Committee on Vaccination and Immunisation is due to imminently decide on whether some people in the UK should get a third dose of vaccine amid emerging evidence of waning protection among older vaccinated patients.
Professor Iain McInnes, from the University of Glasgow, who led the OCTAVE study, told journalists on Tuesday that a booster programme of third jabs would “would be a reasonable next step” for the government to take.
The OCTAVE study, funded by the Medical Research Council. is one of the largest projects in the world investigating the response to vaccines among immunosuppressed patients. Due to concern over the findings and fears patients with a poor antibody response could be susceptible to the virus, the study is planning to enrol patients for a third dose vaccine in coming months.
Among the patients included in the study were those with cancer, inflammatory arthritis, diseases of the kidney or liver and patients who had a stem cell transplant.
The study is vital to understand how clinically at risk patients respond to the vaccines as these groups were excluded from the original vaccine trials.
The worst-affected patients, who generated no antibodies, were those with the inflammatory condition vasculitis and who were being treated with a drug called Rituximab. Almost nine out of 10 of these patients had a worse immune response than healthy patients. Half of those with arthritis had a poorer response, while other groups saw between a third and two fifths having a worse immune reaction to the jabs than standard healthy patients.
Prof McInnes said the results were not necessarily a cause for alarm as patients still created T-cells, another form of immune response. He likened the immune system to the aviation industry saying: “The human immune system has numerous backup systems. Even though patients did not make antibodies they did make T-cells.”
He said this gave the research team some optimism that even among patients with low or no antibody responses there was still some degree of protection against the virus.
Prof Mcinnes said he would take a “cautious rather than pessimistic” view of the research pointing to the fact a majority of patients did mount an immune response that was similar to a healthy control group of younger vaccinated healthy people.
He said a booster programme for these cohorts of patients “would be a reasonable next step” for the government to take.
“In this group who have the slightly lower antibody response, we are emphasising that we don’t what that will mean. The absence of an antibody is probably not ideal and that is why we are now doing the third boost.”
Professor Pam Kearns from the University of Birmingham, which helped coordinate the study, 添加: “We don’t know whether these patients are more vulnerable to Covid-19. We can speculate that is the case but we don’t know that for certain.”
Earlier this week the government confirmed it had purchased 35 million doses of the Pfizer/BioNTech vaccine for next year with the NHS already warning GPs and hospitals to start planning for a Covid vaccine booster rollout alongside this year’s flu jab campaign.
Dr Rob Buckle, chief scientist at the Medical Research Council, 说: “Today’s results will be of concern for the subset of people within those who are immunosuppressed for whom the vaccine didn’t trigger a large protective response. We’re funding an extension to the OCTAVE study to give third jabs to this group, which we hope will deliver a much-needed immunity boost, or identify those who could benefit from other interventions.
So far more than 2,500 patients have been recruited to the trial with this data representing only the initial results with more detailed analysis to come in the future.
Dr Fatima Sulaiman, head of research at Blood Cancer UK, 说: “This study supports previous research which suggests that people with blood cancer are unlikely to respond as well to the Covid vaccines as healthy people after two vaccines and it’s important for this community to continue being cautious.
“We currently do not know what sort of vaccine response is needed to provide protection from Covid, but as many people with blood cancer have a lower antibody response compared to healthy people, it’s important to explore how else we can protect this group from Covid either through alternative treatments or booster vaccines.
“The government needs to give people with blood cancer, and those immunocompromised more generally, support to avoid coming into contact with Covid by writing to them so they understand their risk and by putting in place financial support for those who are unable to work from home.”