Vaccination for H1N1 is now available in Canada. There is much confusion around the vaccine, and in particular, questions related to its relative safety.
Some things to keep in mind when deciding about whether to get the vaccine include:
The question of whether flu shots and vaccines are safe for people with MS comes up frequently as it used to be thought that these inoculations posed a risk for triggering an MS attack. Dr. Paul O’Connor, National Scientific and Clinical Advisor to the MS Society of Canada suggests that flu shots and vaccines are usually safe and are generally recommended after discussion with one’s physician. Dr. O’Connor considers that they are equally safe for people with MS who are taking one of the disease modifying drugs. One small caution is that for people with MS who are taking chemotherapeutic drugs such as mitoxantrone, it would be important to check that their neutrophils are present in adequate numbers, prior to being vaccinated.
Most common reactions after getting the H1N1 flu vaccine are minor and include pain, swelling and redness at the injection site. Other commonly reported reactions are fatigue, muscle and joint pain, and headache. In younger children, a fever, drowsiness, irritability and loss of appetite have also been reported in low levels. Serious and life-threatening reactions are very rare.
Very common: (10%)
Headache; tiredness; pain, a hard lump at the injection site; joint pain.
Very common: (1% - 10%)
Warmth, itching or bruising at the injection site; increased sweating/shivering, flu-like symptoms; swollen glands in the neck, armpit or groin.
Uncommon: (0.1% - 1%)
Tingling or numbness of the hands or feet; sleepiness; sleeplessness; dizziness; diarrhea, vomiting, stomach pain, feeling sick; itching or rash.
All of these side effects usually disappear within 1-2 days without treatment. If they persist, CONSULT YOUR DOCTOR.
Current concern over the H1N1 vaccine derives from the 1976 swine flu vaccine which estimated that 1 per 100,000 people vaccinated acquired a complication called Guillain-Barré (GBS) which is a neurological condition causing muscle weakness. Using current prevalence rates for GBS, a calculation looks something like this:
Without vaccination, one’s risk of GBS is one or two per 100,000 people.
Vaccination may (or may not) increase the risk by less than a tenth of one case per 100,000. The added risk would be something like one in two million.
The risk of death from H1N1 influenza (the disease, not the vaccine) is unknown at this time; it may be as low as one percent, or as high as ten percent. If it is one percent, the risk of death is one thousand per 100,000 cases.
Most public health experts say the risk of vaccination is very low, while the risk of serious complication with H1N1 swine flu is significantly higher.
To keep ‘risk’ in perspective it is important to remember that one in three Canadians is predicted to catch H1N1, and between 1 and 10 of those who do, will have significant complications. Remember too that if you are one of the 1 in 3 Canadians who catch H1N1, chances are excellent that your entire family will get it too!
Young adults and children are disproportionately more likely to have severe H1N1 complications, and the highest rate of hospitalization is in children under the age of 15.
After receiving the vaccine it will take your body about 10 days to activate its immune response, so timing is an important consideration.
The vaccine is NOT recommended for people with allergy to eggs or egg products. Pregnant women and people with compromised immune systems are advised to receive the vaccine without adjuvant. It is also recommended not to get the vaccine if you have a fever.
Adjuvant is a booster added to the vaccine that makes it possible to get the same or better immune response by using less of the dead virus protein in the formulation. In the case of H1N1 adjuvant, the one used is a mixture composed of shark liver oil, vitamin E and polysorbate, an ingredient commonly used as an emulsifier in ice cream.
The recommended doses for H1N1 flu vaccine are as follows:
ADJUVANTED:
All Canadians 10 years of age and older should receive one dose of adjuvanted vaccine; and, children from six months to nine years of age should receive the adjuvanted vaccine in two half-doses, administered at least 21 days apart.
UNADJUVANTED:
Pregnant women should receive one dose of the unadjuvanted vaccine. In cases where the unadjuvanted vaccine is unavailable and H1N1 flu rates are high or increasing, women more than 20 weeks pregnant should be offered one dose of the adjuvanted vaccine.
All data to date indicates that adjuvanted vaccine is as safe as unadjuvated vaccine. Dr. O’Connor, National Scientific and Clinical Advisor to the MS Society of Canada, considers vaccine both with and without adjuvant to be safe for people with MS. If given a choice he suggests on theoretical ground that he would choose the unadjuvanted preparation, however reiterates that he considers both to be safe and effective.
Finally it is important to remember that even those who get the vaccine can still act as a sort of ‘hop on, hop off bus’ for the virus, transmitting it from one place to the other. Hand washing remains an important weapon for all of us as we fight the flu, whether we get the vaccine or not.
For local information on the H1N1 flu and vaccine availability please see your provincial website:
