ST. PAUL, MN -- April 10, 2001 -- Flu shots are safe for most multiple sclerosis (MS) patients and prevent infections that can trigger or worsen MS symptoms, according to a study in the April 10 issue of Neurology, the scientific journal of the American Academy of Neurology.
"This is contrary to popular belief," said neurologist and study author Neville Moriabadi, MD, of Julius Maximilians University in Würzburg, Germany. "Many MS patients and their doctors worry that the vaccine itself will cause a flare-up in their symptoms, but that is most unlikely."
The study examined 12 MS patients and 28 healthy volunteers before and for four months after they had flu shots. None of the MS patients had any worsening of symptoms or any other side effects directly after the vaccination.
Both groups showed a positive response to the vaccine, with increased antibodies to fight off the influenza A virus targeted by the vaccine. And both groups showed no change in T cells reactive against myelin proteins, regarded as disease-causing factors in MS. In contrast, these T cells increased in six patients and four volunteers who happened to develop respiratory infections over the four-month follow-up period.
One patient had a relapse in symptoms after a respiratory infection. MS symptoms for the other patients remained stable over the four-month period.
Of the 12 patients who took part in the study, seven had the relapsing-remitting form of the disease, where attacks are followed by periods of partial or total recovery, and five had the secondary-progressive form of the disease, which steadily worsens.
"The flu vaccine is recommended for MS patients with the relapsing-remitting or secondary-progressive form of the disease who have flare-ups or worsening soon after infections," Dr. Moriabadi said. "It's safe, as it does not cause exacerbations of symptoms or autoreactive responses, and it can prevent influenza infections that might trigger an attack.
Patients with other forms of the disease or with high disease activity should talk to their doctor about whether to vaccinate."
MS involves inflammation within the central nervous system, followed by loss of the myelin that protects the nerve fibers, and later loss of some of the nerve fibers themselves. When myelin is damaged, nerve impulses are not properly transmitted. As a result of the inflammation process, lesions, or plaques, develop in the brain and spinal cord, causing a variety of neurologic symptoms, such as vision loss, numbness or tingling and weakness.
SOURCE: The American Academy of Neurology