Multiple Sclerosis and Flu Shots, It's About Timing
The 2013-2014 flu season is in full swing, and the Centers for Disease Control and Prevention (CDC) is urging everyone to line up for their flu shots. For people with multiple sclerosis (MS), getting a flu shot is about timing.
People who have MS are often treated with disease-modifying drugs, which have been shown to be helpful in mitigating symptoms. Those drugs include interferon beta-1a (Avonex, Rebif), interferon beta-1b (Betaseron, Extavia), teriflunomide (Aubagio), glatiramer (Copaxone), fingolimod (Gilenya), mitoxantrone (Novantrone), dimethyl fumarate (Tecfidera), and natalizumab (Tysabri).
One of the unfortunate side effects of these medications is an increased risk of developing infections, including the flu. That raises the question as to whether it is safe for people with MS to get a flu vaccination or whether it will put them at greater risk of developing the infection.
About flu shots
For the 2013-2014 flu season, the following flu vaccines are available, according to the CDC:
- The trivalent vaccine is composed of an H1N1 virus, an H3N2 virus, and a B strain virus
- The quadrivalent vaccine contains the 3 viruses in the trivalent plus another B virus. The CDC does not recommend one vaccine over another.
According to the National Multiple Sclerosis Society, the injectable flu vaccines, which consist of inactivated viruses, are considered safe for people with MS. It notes that despite previous concerns about the effectiveness of flu vaccines in MSers who take disease-modifying drugs, studies suggest they provide sufficient protection.
One such study was recently published (August 2013) concerning the flu vaccine in individuals taking teriflunomide (7 mg and 14 mg) and interferon beta-1. The researchers found that more than 90 percent of the 128 patients achieved an appropriate level of antibody titers (concentration) for two of the three virus strains in the vaccine.
For the third strain, at least 90 percent of the patients had sufficient titers in the 7 mg and interferon beta-1 groups while only 77 percent reached that level of protection in the 14 mg group. The authors concluded that “teriflunomide generally does not adversely impact the ability of patients with RMS [relapsing MS] to mount immune responses to influenza vaccination.”
Three other general recommendations from the Society are important to note:
- If you are experiencing a serious relapse, delay getting your flu shot by 4 to 6 weeks after the start of your symptoms. Consult with your healthcare provider if you have any concerns or questions.
- Do not get the nasal vaccine called FluMist. It is a live-virus vaccine, which means the ability of the viruses to cause the flu have been weakened but not completely inactivated.
- Do not take the high-dose flu vaccine, which is available for individuals older than age 65. This form has not been evaluated for people with multiple sclerosis
Here’s something else you may not know about flu shots and timing. The effectiveness of the shot reportedly lasts between four to six months, but it provides the best protection after the first two to four weeks.
The decision to get the flu vaccine is a personal one and should be weighed carefully. If you have MS and have not yet gotten a flu shot, is it time?
Bar-Or A et al. Teriflunomide effect on immune response to influenza vaccine in patients with multiple sclerosis. Neurology 2013 Aug 6; 81(6): 552-58
Centers for Disease Control and Prevention
National Multiple Sclerosis Society