Update on Flu Vaccines - Are They Still Important for the Person Who Has Asthma?
This flu season of 2012-2013 has been one to remember. Each year, people who have asthma are advised to get the flu vaccine, because we are considered at high risk for serious, even life-threatening, complications from the flu. This is because the flu is a respiratory infection and asthma already causes us to have weakened respiratory systems, particularly if our asthma is not well-controlled.
Each February, close to a year before the next flu season begins, experts attempt to predict the top 3 strains of flu that may be circulating the following season. There are always new strains of flu virus cropping up and prediction is a difficult task. However, these experts are generally quite successful at picking the strains and the subsequent flu vaccines they develop are highly effective at preventing or at worst, minimizing, the impact of the flu.
But sometimes, they are not as successful at predicting the flu virus strains, and this season seems to be one of them. Even people who were vaccinated have become infected with the flu. However, often times, you will still have a less severe case of the flu because you did get vaccinated and have at least a small amount of protection.
In my next post, I'll talk about what you can do if the worst happens and you DO get the flu. But for now, I'd like to take a look at some new developments on the horizon for flu vaccines.
What's New Right Now
Traditionally, flu vaccine is made using fertilized chicken eggs. It is a months-long process and also involves the use of preservatives such as thimerosal. Although experts have determined that even people with egg allergies and thimerosal sensitivity can safely receive the flu vaccine, it can still be worrisome.
And the reason why the experts aren't always 100% accurate in their flu strain predictions is because they must make them so far in advance due to the time it takes to actually develop and produce flu vaccine. The whole process is very expensive and cumbersome. Not to mention the fact that brand new vaccine must be produced every single year!
This is why scientists have been looking for a better way. And they have begun to make such advancements. This year, two radically new flu vaccines were introduced.
FluBlok is based on a surface protein on the influenza virus called hemagglutinin, rather than on live virus cells. It is produced in insect cells, rather than chicken eggs. Most of the antibodies that battle infection are directed toward hemagglutinin. It is still a strain-specific vaccine, but it can be produced more quickly and without the risk of allergic reactions.
Also introduced this season was a vaccine called Flucelvax, that is grown in dog kidney cells rather than chicken eggs. Both Flucelvax and FluBlok were available in limited quantities this year and not recommended for children or older adults. Still, they definitely represent some exciting developments in flu vaccine technology!
What's Ahead on the Horizon
There are already 2 new vaccines that will be ready for next flu season (2013-2014). One is an injectable vaccine; the other a nasal spray (by FluMist). Both will protect against 4 strains of the flu, rather than the usual 3.
Not yet ready for primetime is research being done at Stanford Lucile-Packard Children's Hospital and 3 other sites in the U.S. using DNA. This vaccine will be made from only portions of a virus' genetic material. When it is injected into the body, it stimulates human cells to make proteins that will mount the proper immune response towards the flu virus.
An added feature of this DNA vaccine is that it is injected into the skin rather than the deeper muscle. Your skin has more immune cells and so this is thought to have a higher probability of success. It may be able to be used alone or perhaps in conjunction with the standard flu vaccine.
The ultimate goal is to develop a flu vaccine that is universal, that would provide protections against ALL strains of the flu, eliminating the need for prediction and the risk that predictions will be less than accurate. This goal is probably still some years in the making, but does appear to be more and more realistic with each year that passes.