StemCell Therapy

A common treatment for inflammatory bowel disease (IBD) blunts the immune response to a Covid-19 vaccine, a study has found.

Exeter University researchers measured antibody responses after vaccination with the Pfizer/BioNTech or the Oxford/AstraZeneca vaccine in 865 people treated with infliximab, an anti-tumour necrosis factor (anti-TNF) biologic drug, prescribed to around two million people worldwide.

Anti-TNF drugs are effective treatments for immune-mediated inflammatory diseases, but by suppressing the immune system, they can reduce vaccine effectiveness and increase risk of serious infection.

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IBD is a term mainly used to describe two conditions, ulcerative colitis and Crohns disease, both long-term conditions that involve inflammation of the gut. It affects at least one in 250 people of the UK population and the prevalence is rising.

The Exeter team found that people treated with infliximab had significantly lower concentrations of antibodies, when compared to 428 people on an alternative treatment, vedolizumab.

After a single dose of vaccine, only about one third of participants (103 of 328) treated exclusively with infliximab generated adequate levels of antibodies to the virus for the vaccine to be considered effective.

In participants simultaneously taking infliximab and immunomodulator drugs, such as azathioprine or methotrexate, the levels of antibodies were even lower after a single vaccine dose; only 125 of 537 met the threshold of a positive antibody test.

However, in a sub-group of people who had previously been infected with Covid-19, and also in the few patients studied who had already had a second dose of vaccine, the vaccine-triggered antibody responses rose significantly, indicating an effective response after two exposures.

Based on these observations, the researchers conclude that people taking anti-TNF drugs should be considered a priority for a second vaccination.

Co-author Dr Nick Powell, of Imperial College London, said: Although we know that this has been an incredibly difficult time for people with IBD, our research indicates that people treated with infliximab should consider that they are not protected from Covid-19 until they have had both doses of a vaccine and should continue to practice enhanced physical distancing and shielding if appropriate.

The study is published in the journal Gut.

Read more here:
IBD treatment blunts immune response to Covid-19 vaccines - iNews

This entry was posted on May 2, 2021 at 1:53 am and is filed under Immune System. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed. |