Multiple sclerosis (MS) drugs can interact with vaccines in ways that affect both the safety and effectiveness of vaccinations. This interaction depends largely on the specific disease-modifying therapy (DMT) a person with MS is using, as these drugs vary in how they influence the immune system. Understanding these interactions is important to ensure that vaccines provide adequate protection without increasing the risk of MS relapses or other complications.
MS drugs, especially immunosuppressive or immunomodulatory therapies, can reduce the immune system’s ability to respond to vaccines. This means that vaccines might be less effective in generating a protective immune response when given during treatment with certain MS drugs. For example, some drugs that modulate immune cells can blunt the production of antibodies after vaccination, potentially leaving the patient less protected against infections.
Live-attenuated vaccines, which contain weakened forms of the virus or bacteria, are generally not recommended for people on many MS therapies that suppress the immune system. This is because the weakened pathogen in the vaccine could potentially cause an infection in someone whose immune defenses are lowered by their medication. For instance, drugs like fingolimod and siponimod (MAYZENT) require avoiding live vaccines during treatment and for a period after stopping the drug to prevent such risks.
Inactivated vaccines, which contain killed pathogens or parts of them, are usually considered safe for people with MS, even those on immunosuppressive treatments. However, the immune response to these vaccines might still be diminished depending on the drug. For example, the annual influenza vaccine is strongly recommended for people with MS because flu infections can worsen MS symptoms, but the vaccine’s effectiveness might be somewhat reduced if the person is on certain DMTs.
Timing of vaccination is a critical factor. For some MS drugs, it is advised to complete necessary vaccinations before starting treatment. This allows the immune system to mount a full response to the vaccine without interference from the drug. For example, vaccination against varicella (chickenpox) is recommended before starting siponimod, with a waiting period of several weeks after vaccination before beginning the drug to ensure full vaccine efficacy.
Some MS drugs require avoiding any vaccinations during treatment unless specifically approved by a healthcare provider. Fingolimod, for example, advises against any immunizations during treatment and for two months after stopping the drug, due to the risk of infections and reduced vaccine effectiveness. Additionally, people on fingolimod should avoid close contact with household members who have recently received live vaccines, as the vaccine virus could potentially be transmitted.
Certain MS drugs can increase the risk of serious infections, including rare but severe brain infections like progressive multifocal leukoencephalopathy (PML). This risk underscores the importance of careful vaccination planning and monitoring during treatment, as infections can have more severe consequences in immunocompromised individuals.
In summary, the interaction between MS drugs and vaccines is complex and depends on the type of MS medication, the kind of vaccine, and the timing of administration. Live vaccines are generally avoided during and shortly after treatment with immunosuppressive MS drugs. Inactivated vaccines are safer but may be less effective. Vaccinations are often recommended before starting MS therapy to maximize protection. Patients with MS should always consult their neurologist or healthcare provider to develop a personalized vaccination plan that considers their specific treatment and health status.
