Vaccinations are an important part of life individually and for our society. Vaccines provide important protections against disease, some potentially devastating. The Center of Disease Control and Prevention (CDC) provides information regarding recommended vaccines for children and adults.
The most familiar vaccine we encounter each year is the influenza vaccine, the flu shot. Although it is a bit early to think about the annual flu vaccine, I will urge you to get the flu vaccine when it becomes available in the fall and to always practice good hygiene.
MS and Common Vaccines
If you are concerned, as an MS patient, that the flu vaccine might increase your risk of MS relapse, research shows that it does not increase risk. A recent study published in the Journal of Neurology (July 2011) provides a systemic review and meta-analysis of the role vaccines may have in the risk of development multiple sclerosis or MS exacerbation.
Researchers found that the risk of developing multiple sclerosis remained unchanged after BCG (tuberculosis), Hepatitis B, Influenza, MMR (measles-mumps-rubella), Polio and Typhoid fever immunization, whereas diphtheria and tetanus vaccinations may be associated with a decreased risk of MS. Further research is needed for the remaining vaccines, according to the report.
MS and the Yellow Fever Vaccine
Although common vaccines are safe for use in multiple sclerosis, a recent study in the Archives of Neurology (online June 2011) indicates that the Yellow Fever vaccine can increase relapse rate in travelers with MS. This study was conducted by the same researchers who undertook the meta-analysis referenced above.
Seven patients with RRMS who were traveling to areas where yellow fever is endemic received the yellow fever vaccine and were observed for two years. To serve as controls, 21 additional patients were included: seven healthy individuals who were age- and sex-matched, seven MS patients who received flu vaccines according to WHO (World Health Organization) recommendations, and seven MS patients who receive no vaccines.
Patients were told to report exacerbations within 72 hours, otherwise they were examined every three months for two years. MRI scans were conducted three months and nine months following the vaccination, and the scans were compared to scans conducted 12 months prior to the beginning of the study. Relapses were analyzed both during the “at risk period” between one and five weeks following vaccination and the “non-risk period” which was the remaining time of weeks six to 104. Since the yellow fever vaccine contains a live virus, researchers began measuring the ARP one full week after vaccination.
For the entire two-year time period, the annual relapse rate was 0.99 with five (of seven) patients experiencing 14 exacerbations. There were five relapses during the at-risk period (annualized relapse rate of 8.57) and nine relapses during the non-risk period (annualized relapse rate of 0.67). The exacerbation rate was 12.778 times higher [emphasis mine] during the at-risk period. Patients also had more lesions three months after immunization as compared to 12 months before the study and during the two-year follow-up. Two of the seven patients in the test group had no relapses or additional lesions at any time during the study.