- Multiple sclerosis (MS) is an autoimmune disorder that affects the central nervous system (CNS) and can cause mild to severe neurological symptoms.
- While drug treatments for MS can reduce symptoms of the condition, they may also lessen the body’s vaccine immune response.
- A new study finds that people taking the MS drug cladribine still show protective antibodies to two common vaccines.
- These findings may offer hope that people with MS who are treated with this and other disease-modifying drugs may produce adequate protective antibodies to other vaccines.
MS is an autoimmune condition that impacts the CNS. MS symptoms include numbness or tingling sensations in the face, arms, legs, or other parts of the body, fatigue, blurred vision, memory and concentration issues, and problems with coordination and muscle strength.
Estimates indicate there are 2.8 million people with MS globally.
Scientists still do not fully understand the cause of MS. However, symptoms occur because of inflammation and damage to the
This damage is the result of the body’s immune system mistakenly attacking healthy nerve cells. Symptoms may be mild or severe and can occur occasionally or persistently, but they often worsen over time.
Relapsing-remitting MS (RRMS) is the most common form of the condition and presents with periods of increased symptoms followed by days, months, or years of remission.
There is no cure for MS. However, drug treatments include steroid medications and condition-modifying therapies in injectable, infused, and oral forms.
One of the latest medications for MS is an oral pill called cladribine (Mavenclad) manufactured by EMD Serono.
Cladribine may reduce the symptoms of MS through its action of targeting and lowering the number of adaptive immune cells called lymphocytes that circulate in the body. This reduction of lymphocytes means there are fewer immune cells available to attack nerve cells.
However, having reduced lymphocytes in the blood lowers the body’s ability to fight viruses or mount an adequate vaccine response.
This means vaccines given during or around the same time as MS therapy drugs may not produce the desired antibody response.
To investigate protective antibody responses to vaccines in individuals treated with cladribine, researchers looked at how a small cohort of people treated with the drug responded to the
Study results premiered at the virtual Americas Committee for Treatment and Research in Multiple Sclerosis Forum, which took place between February 25 and 27, 2021.
Using the results of blood samples taken from people treated with cladribine before and after vaccination, investigators found the following:
- Twelve people who received the seasonal influenza vaccine produced protective antibodies to the influenza virus that lasted for at least 6 months after vaccination. These results did not depend on lymphocyte blood levels measured at the time of vaccination in year 1 or 2 of cladribine treatment.
- In a sub-analysis of three people treated with at least one dose of cladribine before receiving the influenza vaccine, protective antibodies were increased 4 weeks after the shot. At the time of vaccination, one person treated with the drug 2 months previous and one person treated 4 months before the vaccine dose had decreased lymphocyte levels in their blood. These lower levels did not appear to impact the body’s ability to mount an immune response to the vaccine.
- Three individuals who received the VZV vaccination 1 year before beginning cladribine treatment also produced protective antibodies. These protective levels continued past 6 months after starting the drug, despite depletion of lymphocytes.
Dr. Klaus Schmierer, professor of neurology at Queen Mary University of London and The Royal London Hospital in the United Kingdom, comments on the results:
“Understanding vaccine efficacy in MS patients is particularly important in the face of the current pandemic and the growing availability of COVID-19 vaccines. Whilst this new information is based on a small cohort of patients receiving influenza and varicella zoster vaccines, it provides physicians with preliminary evidence that patients taking Mavenclad are able to mount and maintain effective vaccine responses.”
The MAGNIFY-MS study used in this research was sponsored by the Mavenclad manufacturer, EMD Serono, a biopharmaceutical enterprise of Merck KGaA, Darmstadt, Germany, in the United States and Canada.
Because of this, further investigation by independent researchers is needed to verify results.
Moreover, the number of study participants was limited. In the full MAGNIFY-MS 2-year trial, 270 participants have been enrolled. However, the number of people with relapsing MS who partook in the vaccine portion of the research is unknown.
Further evaluations using a greater number of people could reveal whether these preliminary results remain consistent across a wider population.