by Dr. Y.L.M
I’m thinking of getting myself vaccinated against the flu. But my mother told me I might get sick from the vaccine itself. I'm a little hesitant. What is a flu vaccine?
A vaccine is generally a biological preparation that confers immunity to a particular disease. In this case, we are talking about the flu vaccine, so this vaccine will confer immunity against the flu ... for a period of time.
A vaccine does this by stimulating the body's immune response to the micro-organism we want to be immune to. Once certain cells (called lymphocytes) are stimulated to produce antibodies, some of these will carry a memory of the micro-organism's structure. The next time the same micro-organism attempts to invade the body, the body mounts a swift response before the 'invasion' occurs.
There are 2 types of flu vaccines – an injection form (with killed viruses) and a nasal spray vaccine (with live but weakened viruses).
The flu vaccine is around 70 to 90% effective, which means it won't totally prevent you from getting the flu.
I’ve heard most vaccines confer immunity to the disease for life, but not the flu vaccine. Why is this so?
This is because of the nature of the flu virus. Each year, it mutates slightly, thus rendering the vaccine used in the previous year inactive.
The flu virus is one of the most versatile and durable of viruses because of its penchant to forever change its structure. That is also why the flu virus is so effective in causing widespread disease.
Therefore, you need a new flu vaccine every year and you need to go for your jab annually.
Does this mean that in order to produce a new flu vaccine every year, the scientists will have to wait for the virus to mutate? Then what will happen to us in the months between the virus mutating and the production of the new flu vaccine?
Scientists do not actually wait for the virus to mutate, but they predict instead which types of flu viruses will cause the disease for the following year, and prepare the concoction to combat those. They are usually quite accurate in their predictions.
Within 2 weeks of your injection, the flu vaccine will be effective.
But influenza is not a very dangerous disease, right? I shouldn't need to vaccinate against it.
Don't forget that influenza once killed over 20 million people in the outbreak of the early 20th century. It is best to vaccinate against it as the flu virus is highly infectious. And influenza as a disease in itself is not a common cold – you are quite ill with a fever, body aches, and fatigue. You will miss work or school.
But the worst thing is the possible secondary infection on top of your flu. If you get bacterial pneumonia as a complication, this may lead to death in old people and very young babies.
Which one is better – the injected flu vaccine or the nasal spray?
They are different. One is better for certain groups of people. The injected flu vaccine is an inactivated vaccine, which means it contains killed flu viruses. This is injected into the muscle, usually that of the upper arm. Your immune response is stimulated to produce antibodies to the flu viruses that are injected inside you. The next time those same viruses enter you, these antibodies will attack and kill the viruses before you get ill.
There are some side effects, but they are not common. These include soreness at the injection site, muscle aches, fever, a general feeling of being ill. Very rarely do allergic reactions occur.
Around one in a million people who get the flu vaccine might acquire Guillain-Barre Syndrome.
The nasal spray flu vaccine contains weakened live influenza viruses instead of killed viruses. This is called a live attenuated virus. It targets the same viruses as the injected vaccine.
But it is considered not as strong as the injected vaccine in one recent study. People at risk for flu complications like children less than five years of age who have recurrent wheezing, people with chronic heart and lung disease, pregnant women, toddlers, the elderly (over age 50), and people who have a suppressed immune system are generally not advised to take the nasal spray vaccine.
If I currently have the flu, can I take the flu vaccine?
If you have been ill recently with a fever, you should not be taking the flu vaccine just yet, though if you have a cold or mild disease without a fever, you can take it.
It must be noted that people with allergy to chicken eggs should not take the flu vaccine.
Will this flu vaccine cover me against influenza A(H1N1)?
No. There are a couple of new vaccines for that and they are now available in hospitals and clinics throughout Malaysia.
More info on FLU VACCINE here.
8:10 AM Flu