We get it. Some people are nervous about the unknown, and when it comes to the new H1N1 flu vaccine, many are skeptical about whether to get it now or wait for more proof of its effectiveness and safeness.Dr. Mike Evans, associate professor of family and community medicine at the University of Toronto and staff physician at St. Micheal's Hospital in Toronto, presents the 10 most important questions and answers that can help you make an informed decision whether to get the swine flu vaccine for you and your family.
1. What is the likelihood of getting sick from the H1N1 this year?
The usual attack rate for the regular flu is 9 to 12 out of 100 people, which can go up to 42 per cent if you have young children. H1N1 appears to have higher attack rates as data from the U.S. shows that they are already at the highest rates in 5 years. However, Evans says, that although attack rates for H1N1 influenza are on the rise, your chances of getting it are “still less than a coin toss.”
2. How sick will I get?
Infuenza exhibits worse symptoms than the common cold. According to Evans, most people who get sick from H1N1 influenza are able to cope. Some, however, require hospitalization. Based on U.S. H1N1 data, 11 out of 1,000 who got infected with H1N1 needed hospitalization and 7 out of 10,000 have died. About 70 per cent of people who have been hospitalized with H1N1 have had one or more medical conditions that placed them in the “high risk” category, including pregnancy, diabetes, heart disease, asthma and kidney disease.
3. Will the H1N1 vaccine actually protect me?
The effectiveness of the influenza vaccine depends on how the virus – mostly dead virus – that’s injected into you to make you immune matches with the virus that is circulating in the community and on your own immune system, Evans explains. “It is still early but it looks like the match with what is in the community is very accurate and so, hopefully, the H1N1 vaccine will be on the upper end of effectiveness.” The H1N1 vaccine works in about 10 days.
4. How do vaccines work?
Evans explains: Your body’s immune system is very smart. If you get invaded by a “bad virus,” your body makes a “photocopy” and sends it around so that if the virus shows up again it neutralizes it and you don’t get sick. Instead of allowing you to get sick, vaccines give you a dead or even a very small live part of the virus so that your immune system is prepared to fight off the real virus. The H1N1 vaccine gives you a dead virus for your immune system to “photocopy.” The H1N1 vaccine in Canada has an adjuvant, which is an additive that is sometimes put in vaccines to boost the effect. However, there isn’t much trial experience for the adjuvant among pregnant women and very young children. Hence, the vaccine is not recommended for children below 6 months old, and pregnant women with less than 20 weeks into their pregnancy may get the vaccine but without the adjuvant.
5. What are the side-effects: Didn’t I get sick the last time I got a flu shot?
According to Evans, about 20 per cent of people will develop symptoms after a flu shot. But before you go on blaming your health woes on the flu shot, the U of T professor notes the vaccines generally takes two weeks to work – so people can get sick with flu if they are exposed before the vaccine takes effect. People with egg allergies should not get the flu shot, as well as those with true allergic reaction to the flu shot.
6. What are the side-effects: What about the scary stuff I read on the Internet about mercury and paralysis?
About one in a million will have a severe reaction to the flu shot, according to Evans. Data is conflicting whether there is causal relationship between modern influenza vaccines and GBS (Guillain-Barre syndrome). If one exists, the risk is estimated to be very low – no more than 1 to 2 cases per million doses, Evans says.
There is also concern about thimerosal, which is preservative for vaccines and most influenza vaccines in Canada contain minute amounts of it. Thimerosal has some mercury in it, hence the safety concerns. The H1N1 vaccine has an adjuvant which means we need about one-tenth of the usual amount of thimerosal, Evans notes. “To keep things in perspective, there is less mercury in the shot than in a tuna sandwich.”
7. Does my decision affect others?
Aside from thinking about how the H1N1 influenza can affect you, another factor you should consider is the effect of your health on others, says Evans. In his case, the U of T professor says his main reason for getting the flu shot is because he sees many older and sick people in his work and he wants to protect them. “If you get the shot, you reduce the risk for people in your life who may struggle with dealing with H1N1 swine flu and conversely, if you get the kids the shot, your chances of getting sick go down quite a bit.”
8. What are the risks versus the benefits?
Based on available data, Evans says that a person’s chance of getting the H1N1 flu and getting quite sick is likely about one in four, and higher if they have small kids. The chance of a negative lasting consequence from the vaccine is around 1 to 2 in a million. Your arm will likely be sore for 2 days after getting vaccinated, but the pain doesn’t limit normal activity.
9. What are the recommended doses for the use of the H1N1 flu vaccine?
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.
10. Will you vaccinate your kids and yourself?
Evans says, “Yes.”
