Research News

Vaccination Safety
Recent studies continue to affirm the safety of vaccinations for people with MS. An evaluation of several reports and trial outcomes by the US Penitentiary Health Services Unit in Terre Haute, IN, concluded that the hepatitis B (HB), influenza, and tetanus vaccines do not increase the risk of developing MS or exacerbating its symptoms.

Although an acute central demyelinating event following HB vaccination was reported in a portion of those vaccinated in France between 1991 and 1999 (several hundred out of roughly 12 million vaccinated), follow-up studies failed to establish the causality of the HB vaccine. The Centers for Disease Control and Prevention in Atlanta, GA, report that immunizations are unlikely to be a major cause of autoimmune disease (AID), but point out the need for additional epidemiological studies to asses the risk in some susceptible individuals. While some evidence for immunization leading to AID comes from several sources including animal studies, more rigorous (or scientifically accurate) investigation has failed to confirm most of these claims.

A case-crossover study (at the European Database for Multiple Sclerosis Coordinating Center and the Service de Neurologie A, Hospital Neurologique in Lyons, France) was conducted to determine if vaccinations increased the risk of relapse in MS. Researchers contacted 643 individuals with MS who experienced a relapse between 1993 and 1997, but who had no other disease exacerbation for at least one year prior to that time. Relapses were confirmed by visits to the neurologist, and information on vaccinations was confirmed through medical records.

No evidence of specific risk for relapse was associated with tetanus, HB, or influenza vaccinations. Researchers concluded that vaccines do not appear to increase the short-term risk of relapse in MS.

An earlier article written by AE Miller, et al, for Neurology, provides results of a multicenter, randomized, double-blind, placebo-controlled trial of influenza immunization in MS. The article states, “Prevention of a febrile viral illness is clearly desirable in MS, and previous studies suggest that immunization is safe. Despite this, many clinicians avoid vaccination because they fear precipitating an MS exacerbation.”

More than 100 people with MS at five MS centers were given the standard influenza vaccine or a placebo. The researchers concluded, “The two groups showed no difference in attack rate or disease progression over six months. Influenza immunization in MS patients is neither associated with an increased exacerbation rate in the post-vaccination period nor a change in disease course over the subsequent six months.”

These studies and others continue to support the safety of vaccinations for individuals with MS. This is good news for people who would like to have added protection against one of the previously mentioned illnesses (hepatitis B, tetanus, and influenza). Individuals with MS should consult their physician before receiving any vaccination to be sure that other health conditions would not be affected.

Sources for this article include:

• Chen RT, et al, Epidemiology of autoimmune reactions induced by vaccination, Journal of Autoimmunity, vol. 16 (3) pp. 309-318, May 2001.
• Confavreux C., et al, Vaccinations and the risk of relapse in multiple sclerosis, New England Journal of Medicine, vol. 344 (5), pp. 319-326, Feb. 2001.
• Gout O, Vaccinations and multiple sclerosis, Neurological Sciences, vol. 22 (2), pp. 151-154, April 2001.
• Miller AE, et al, A multicenter randomized, double-blind, placebo-controlled trial of influenza immunization in multiple sclerosis, Neurology, vol. 48 (2), pp. 312-314, Feb. 1997.
• Sievers EJ, Heyneman CA, Relationship between vaccinations and multiple sclerosis, Annals of Pharmacotherapy, vol. 36 (1), pp. 160-162, Jan. 2002.

Limited Baclofen Availability
A shortage of the drug baclofen (Lioresal®), in its oral tablet form, has been reported by Magee Rehabilitation of the Jefferson Health System. Many individuals with MS or other neurologic conditions depend on baclofen to treat spasticity. Causing muscle stiffness or spasms, spasticity is one of the most common symptoms of MS, and baclofen is the medication most often prescribed for this symptom. The shortage does not involve the form of baclofen used for the implanted pump.

A lack of raw materials has been blamed for the shortage, which was originally expected to continue until at least January 2003, when new materials to make the drug would become available. The pharmacy director from Magee believes that the raw materials may arrive at the pharmaceutical companies much earlier, possibly by November. Meanwhile, Magee was able to locate one drug company that could still supply the drug.

Individuals who take baclofen should check with their pharmacy for availability before their medication runs out and a refill is needed. Should a pharmacy not have a supply, individuals may either check with other local pharmacies, or ask their pharmacy to contact various suppliers.

People taking baclofen must be weaned off the drug slowly – discontinuing it abruptly can cause serious and even life-threatening symptoms, including increased spasticity, delirium, and seizures. Should the drug not be available at any time, individuals need to contact their physician for instructions. Alternative medications include tizanidine (Zanaflex®), dantrolene (Dantrium®), clonazepam (Klonopin®), diazepam (Valium®), chlordiazepoxine (Librium®), cyclobenzaprine (Flexeril®), and carbamazepine (Tegretol®), but some of these come with unwanted side effects, including excessive sleepiness and drug dependency.