Each year the strains of flu that affect humans are different. However, one thing that is not different is that the flu is a very contagious and dangerous illness, causing hundreds of thousands of hospitalizations and tens of thousand of deaths each year. This is why scientists monitor the strains of flu that move through Asia to develop vaccines that will help us develop immunity against the impending infections. Flu season extends from October to May in the United States, which is why the vaccine is generally available by September.
What is a Flu Vaccine and How Does it Work?
Humans have a very smart immune system. When foreign bodies such as viruses infect our bodies, we have 2 immune responses that go into action. First, our innate system mounts a general attack on the virus. White blood cells (WBC) go into action to kill and remove the invading organism. At the same time, a series of chemicals are released that cause inflammation, trying to isolate the organism and make the environment very unfriendly. Finally, our adaptive (or acquired) immune system puts the final touches on our response. When a new foreign entity (antigen) is identified, this system creates antibodies that will recognize future infections or exposures. These antibodies will respond to any future infections or exposures and create a response that will neutralize and destroy whatever antigen is targeted.
Vaccines are developed to activate the adaptive immune system. Each year, a new set of flu vaccines are developed with viruses obtained from the CDC or other government regulated labs. The most commonly used flu vaccines are developed by injecting the virus into chicken eggs. The virus is allowed to replicate in this environment, and then the fluid is harvested. At this point the viruses used for the injectable vaccine are killed.
Another type of flu shot that is being developed is called a recombinant vaccine. In the development of this vaccine, a whole virus is not used, but rather a protein from the virus. This vaccine does not need eggs as a host because there is no virus to replicate. In other words, the flu virus contained in the injectable flu vaccine is either not alive, or is only a part of a virus that is not alive. When the vaccine is injected into your arm, your innate system may react and cause some local tenderness. However, your adaptive system will identify the new virus and start making antibodies. This is how immunity is obtained. If you are exposed to one of the strains of the flu virus in the vaccine, your antibodies that have now been created will jump into action to start fighting the infection. Once receiving the flu vaccine, it takes your body about 2 weeks to develop full immunity.
Can the Flu Shot Give You the Flu?
Many people are convinced that you can get the flu from a flu vaccine. In fact, they may have a story about how they know someone that got the flu two days after they had the vaccine. The fact is, as stated above, there is no live virus present in any of the recommended flu vaccines. Therefore, there is no way that you can get the flu from the shot. The most common side effects after getting the flu vaccine are soreness, redness, or swelling at the site of injection. You may also get some body aches, headache, and low-grade fever.
So, why the stories about getting the flu after getting the shot? There are a number of explanations. First, there is always the possibility that someone is exposed to an illness other than the flu, or a strain of the flu that is not covered in the vaccine developed for that season. Additionally, if you are exposed to the flu a few days before, and up to 2 weeks after receiving the vaccine, you will not yet have full immunity and therefore are susceptible to coming down with the flu. What is absolutely certain is that there is no way to get the flu from the vaccine itself.
It is important to remember that the flu can be a very serious illness, especially in the very young, the very old, and the chronically ill. However, even if you do not fall into one of these categories, you can get very sick and possibly be hospitalized if you get the flu. The CDC recommends that every person should get the vaccine every year, beginning at 6 months of age. If you have any further questions about the flu vaccine or any other preventative health measures, or if you would like to arrange to get the flu vaccine, please call Patient Care Now Urgent Care at our Fairless Hills location at (267) 202-6433 today. We look forward to helping you achieve your highest level of health.