Influenza is a nasty illness. It isn’t just a bad cold. This viral infection kills up to half a million people in the world every year. And that’s in a good year. In a bad year, like 1968, the Hong Kong flu killed a million people and back in 1918-20 the Spanish Flu sickened about 500 million and resulted in over 20 million deaths. So it seems that if there is an effective way to reduce the risk of catching and spreading this nasty bug we should take advantage of it. And there is. The annual flu vaccine. Does it work 100 percent of the time? No. No medication does.
The flu vaccine introduces a small dose of an inactivated virus which then stimulates the body to produce antibodies that will engage and neutralize the active virus should it present itself. The problem is that there are many varieties of flu virus and every year scientists at the Centers for Disease Control in Atlanta make a guess as to which viruses are likely to circulate that winter season. The three most likely candidates are then incorporated into the annual vaccine. In general, they make very good guesses. We know this because statistics indicate that in populations where vaccination incidence increases, flu incidence decreases. To put a number on the effectiveness is difficult because there are many variables and not all cases of flu are recorded. The vaccine is more effective in children and healthy adults than in the elderly because their immune system is more vigorous and produces antibodies more readily.
Numerous studies have examined the effectiveness of the flu vaccine in the general population and there is no doubt that they reduce the chance of contracting the disease but by how much isn’t clear. Estimates run from 25 to 75% depending on the age group being looked at and whether the virus strain in the vaccine matches the circulating virus. The greatest protection is offered to children and healthy adults. As far as health care workers go, it is clear that as vaccination rates of personnel in direct contact with patients rise, the risk of a flu outbreak in the facility declines. And this is really important because frail, elderly patients don’t get much protection from vaccines due to their already impaired immune systems.
There is yet another motive to go for the jab. In the year following an inoculation, the shots are associated with about a 50% reduction in the risk of having a heart attack, stroke or sudden death from heart disease. Respiratory infections put a stress on the heart and an infection with the flu virus causes inflammation and inflammation is known to cause plaque in coronary arteries to burst, which in turn can trigger the formation of a blood clot and consequently a heart attack. Of course the benefits of the vaccine have to be evaluated relative to any risk. As with any intervention, there is a risk. But it is very small. People with allergies to egg protein should not take the vaccine since it is produced by growing the virus in eggs. Fever, aches, mild flu symptoms and soreness at the point of injection are possible. Guillain-Barré syndrome has been linked by some to vaccination but the fact is that the flu itself increases the risk of this paralytic disease more than vaccination. Given that the flu is a serious ailment, the risk-benefit ratio is clearly on the side of benefit. I’ve been jabbed. Have you?
