Four in 10 immunocompromised people have a “low or undetectable” level of immunity after two vaccines

Four in 10 people with weakened immune systems show “low or undetectable” levels of Covid immunity after being double vaccinated, a major UK study has found.

The discovery will put pressure on government science advisers to give the green light to a recall program for the most vulnerable Britons this fall.

Researchers at the Universities of Glasgow and Birmingham measured antibody levels in 600 immunocompromised people and compared them to healthy volunteers.

About one in ten in the vulnerable group failed to generate detectable Covid antibodies four weeks after their second dose of Pfizer or AstraZeneca.

Another 30% generated a significantly lower antibody response than in healthy people, according to the study published as a pre-print in The Lancet.

Scientists pointed out that almost all of the people who did not show an antibody response had vasculitis, a disease that causes inflammation of blood vessels.

They added that in almost all of the patients, the T-cell response was similar to that of healthy adults, indicating that they were at least partially protected against Covid.

While antibodies are the most obvious indicator of immunity, T cells – a type of white blood cell – also play a crucial role in preparing the body for disease.

The experts behind the study asked the Joint Committee on Vaccination and Immunization (JCVI) to approve the booster doses for the immunocompromised in the coming weeks.

Daily Covid infections, deaths and hospital admissions in Britain have been increasing slowly but steadily for several weeks, raising fears of a new wave when schools return and reinforcing the case for recalls.

People who are immunocompromised include those with certain types of arthritis, inflammatory bowel disease, and certain cancers.

Sources say the JCVI is set to roll out third doses for this group starting in September, but will stop on a mass recall campaign to entire age groups and wait for more evidence of the benefits.

To determine how well immunosuppressed people are protected from vaccines, research looked at the levels of antibodies and T cells in 600 of them before a vaccine, after one dose, and after both injections. They compared this with samples taken from 231 healthy individuals.

Four weeks after receiving a second dose, 100% of healthy Britons produced antibodies.

But only 89% of immunocompromised people did – meaning more than 1 in 10 people had no antibodies to protect themselves against the virus.

And there were even fewer in certain subgroups of immunocompromised people.

For example, 72 percent of people with vasculitis did not produce antibodies after two doses.

The researchers said these patients were taking drugs that shut down the production of antibodies to calm their immune systems, making it very difficult for them to prepare a response to the vaccine. Patients with solid cancers tended to have high levels of antibodies.

They said their findings “strongly” supported the administration of booster doses to people with chronic illnesses or on immunosuppressants.

Professor Iain McInnes, a rheumatoid and psoriatic arthritis expert at the University of Glasgow and study leader, said the lack of an antibody response in some vulnerable was concerning, but said there were concerns. positive elements to be drawn from the study.

He noted that it is not clear what correlation exists between the antibody response and the likelihood of getting an infection or the severity of the infection.

Professor McInnes said: “I want to stress that the group of patients who did not make antibodies were mostly contained in the vasculitis group, and the vasculitis group is a rare disease group in this country.”

And the “vast majority” of people who have solid cancer – a cancerous growth rather than one in the blood – as well as those with immune disease, inflammatory bowel disease, or arthritis “will probably be fine. , but more work needs to be absolutely reassured, ”he said.

The researchers also found that healthy and immunocompromised patients – including those with vasculitis – had similar T-cell responses to jabs.

And Professor McInnes said the majority of immunocompromised patients developed an immune response that appeared “remarkably similar” to a healthy control group.

Some 60 percent of participants with “fairly significant conditions actually look the same as people who otherwise have an intact immune system,” he added.

Britain is under increasing pressure to launch its own mass deployment.

JCVI should only allow third doses for vulnerable adults with weakened immune systems.

The boosters will almost certainly be offered to the 3.7 million Britons classified as “extremely clinically vulnerable” with diseases such as cancer.

But originally, it was hoped the program would be open to anyone over 50, key workers and sick patients, which would have included up to 32 million people.

Some scientists have said the vaccines should be used to deliver the first doses to people in other countries before the third doses are offered in the UK.

Professor Eleanor Riley, an expert in immunology and infectious diseases at the University of Edinburgh, said the results were ‘unsurprising’ but ‘important’

It’s no surprise that many risk groups have lower antibody responses after two doses than healthy people, she said.

But it is promising that many had a detectable antibody response after a dose that escalated after a second jab, Professor Riley said.

She added: “It is quite possible that they react even better after a third dose of the vaccine.

“These data therefore support the idea that people with specific comorbidities should be given priority for a booster dose of vaccine in the coming weeks.”

Professor Neil Mabbott, chair of immunopathology at the University of Edinburgh, said the results suggest that boosters should be given to those with weakened immune responses.

He said: “There is a lot of debate in the UK as to whether we should roll out booster shots for adults who have already received two doses.

“Of course, we currently do not have a reliable serum marker that can tell us if and to what extent an individual is protected against developing severe Covid disease after vaccination.

“Despite this, the results of this study provide useful evidence to inform these decisions.

“This study supports the suggestion that if booster shots are to be used, they should be prioritized for people, such as the people in this study, who have weakened immune responses and have responded poorly to their previous vaccinations.”