Treatments used to help people with multiple sclerosis (MS) manage their condition can reduce the effectiveness of COVID-19 vaccines, according to a new study led by Cardiff University.
Disease-modifying therapies (DMTs) are a group of treatments that suppress the body's immune system and are used by people with MS and other conditions such as cancer and rheumatoid disease. As vaccines work by triggering the body to produce an immune response, it was suspected that some DMTs could reduce the effectiveness of COVID-19 vaccines.
This new study, led by Cardiff University and Queen Mary University of London (QMUL), and involving sample collection at five sites across the UK, is published in the journal Annals of Neurology, provides the largest peer-reviewed evidence of the effect of MS DMTs on immune responses to COVID-19 vaccines.
It is hoped this new information will better equip clinicians to provide guidance to people with MS on treatment and vaccination.
Dr Emma Tallantyre, Clinical Senior Lecturer in Neurology at Cardiff University, said: "Questions about the COVID-19 vaccine are among the most common we are currently facing from people with MS in our clinics.
"Highlighting groups who have mounted an inadequate vaccine response has already been helpful in guiding who should receive additional doses of the vaccine, and who may need to continue to take additional infection-prevention precautions over the winter.
"We hope further work will allow us to individualise our management, to protect people with MS from COVID, while keeping their MS under control."
The research team studied almost 500 people with MS and used a technique known as dried blood spot sampling to investigate the effects of DMTs on COVID-19 vaccine effectiveness.
They found people with MS taking either of two particular DMTs, fingolimod and ocrelizumab, were less likely to produce antibodies in response to AstraZeneca and Pfizer vaccines than people with MS not taking any DMT.
If they did produce antibodies, the levels were lower than those found in people taking other DMTs, or not taking any DMT at all. However, the researchers found that other DMTs, including some that are highly effective for MS treatment, had no detrimental effect on vaccine response.
