The COVID-19 pandemic is a major concern for people on long-term treatments that modify the immune system function. People with multiple sclerosis (pwMS) form a large group who receive such treatments called disease modifying therapies (DMTs). Several types of DMTs with different effects on the immune system are being used for multiple sclerosis (MS). In the absence of large-scale national studies, the risk of COVID-19 among pwMS on various DMTs has not been established.

A few physician-reported registry-based studies have suggested that anti-CD20 monoclonal antibodies, such as ocrelizumab and rituximab, used in the treatment of MS can increase the risk of COVID-19. However, in our community-based COVID-19 study of a large cohort of pwMS as part of the UK MS Register, we could not demonstrate an association between DMTs and susceptibility to COVID-19. Other studies have not found any relationship between DMTs and the outcome of COVID-19 among pwMS.

To our knowledge, UK is the only country in the world that collects national data on DMT use, providing us with the opportunity to investigate the impact of DMTs on COVID-19 susceptibility and severity in a large population of pwMS. In England, no DMT is being dispensed without prior approval and specialised commissioning by the national Health Services (NHS) England & NHS Improvement (NHSE/I). The scheme, currently implemented in over 100 NHS Trusts in England, ensures that treatment decisions are made in line with agreed commissioning policy and are evidence-based. NHSE/I also has access to Public Health England (PHE) held data on all people who have had a SARS-CoV-2 test. By identifying all pwMS on DMTs and all those who have had a test for coronavirus and collecting data on the clinical outcome of their COVID-19 from their local NHS hospitals, we would be able to establish the risk of COVID-19 and the risk of contracting the infection associated with different DMTs. The findings of the study will help MS clinical teams address the concerns of pwMS about taking DMTs during the COVID-19 pandemic and update their guidelines on the measures pwMS need to take during these unprecedented times.

Inclusion Criteria:

• Age 18 or above
• Diagnosed with MS
• Received treatment with a DMT

Exclusion Criteria:

• Not fulfilling the inclusion criteria

The study population is all people with MS taking DMTs in England.