October is the beginning of the flu season. Are you going to get a flu shot? This seems to become a more controversial question every year. Here are some considerations you can take into account to help make your decision.
WHAT IS THE FLU SHOT?
The flu shot is a vaccine intended to protect you against influenza viruses. Influenza, or “the flu” for short, is a contagious respiratory infection that can affect your nose, throat and lungs. It can cause mild to severe illness and possibly even death.
Over 200 viruses cause influenza, and every year researchers predict which strains will be the most prevalent during the year’s flu season. A new vaccine is created each year that provides protection against three or four targeted flu strains.
The Centers for Disease Control (CDC) has complete details on the various formulations of vaccines available this year.
HOW ARE FLU VACCINES MADE?
Flu vaccines contain inactivated (killed) influenza viruses. Introducing these inactive viruses into your body will promote the development of antibodies that can protect you against the flu. It takes about two weeks after you have been vaccinated to develop enough antibodies for immunity.
All flu vaccines are made by private companies. Different manufacturers use different production techniques, but they are all approved by the Food and Drug Administration (FDA). The three approved production techniques are:
Egg-Based Flu Vaccines – This process starts with growing influenza viruses in chickens’ eggs. Then the viruses are injected into fertilized hens’ eggs and allowed to replicate over several days. Fluid containing the viruses is taken from the eggs, and the viruses are killed and purified prior to use in the flu vaccine.
Cell-Based Flu Vaccines – Viruses are also initially grown in eggs for this process. Then they are mixed with mammalian cells to replicate over several days, and the virus-containing fluid is collected, inactivated and used for vaccines.
Recombinant Flu Vaccines – These are the only type of egg-free flu vaccines. Instead of an initial egg culture, certain proteins are isolated from an influenza virus. These proteins are combined with portions of another virus and mixed with insect cells to replicate over time, before they are collected and purified like the egg-based processes.
WHEN IS THE FLU SHOT RECOMMENDED?
The CDC recommends everyone 6 months and older get a flu shot each year, with a few exceptions. Different types of flu shots are approved for people of different ages, so check with your doctor to make sure you’re getting the right one for you.
Those who should not get a flu shot include:
- Children younger than 6 months.
- People with severe allergies to a flu vaccine or any of the ingredients in the vaccine.
It’s recommended you speak to your doctor before getting a flu vaccine if:
- You are allergic to eggs or any of the vaccine ingredients.
- You have ever had Guillain-Barré syndrome.
- You are not feeling well.
WHAT CONCERNS HAVE BEEN RAISED ABOUT THE FLU SHOT?
Ingredients – The fact the vaccines start with cultures using animal products can be an ethical concern. Ethics aside, other ingredients in flu vaccines are potential toxins. These are present in small amounts, but many question whether or not the injection of any of these chemicals directly into your blood stream is safe.
For instance, Fluzone, a common brand of flu vaccine, contains residual formaldehyde and octylphenol ethoxylate, which are used during its production. Fluzone also contains some mercury as a preservative.
Some brands of flu vaccine contain gelatin, so if you’re vegan make sure to ask about the ingredients before you get a shot.
Effectiveness – The CDC has tracked the effectiveness of the flu vaccine since 2004. The average effectiveness of the vaccine from 2004 to early 2016 was 41 percent. In other words, only 41 percent of people who received the flu shot were protected against the flu.
Of the 200 viruses that can cause influenza, it’s estimated that vaccines may only be effective against 10 percent of circulating viruses. Also, there is very little evidence flu vaccines are effective for people over 65 or under two years old.
Side Effects – Many possible side effects from the flu vaccine have been reported. For instance, the product label for Fluzone states that the vaccine may be related to the following events:
- Anaphylaxis or other allergic reactions
- Ocular hyperemia
- Guillain-Barré syndrome (GBS)
- Facial palsy
- Dyspnea (shortness of breath)
- Stevens-Johnson syndrome
- Pain in extremities or chest
Lack of Research – Various aspects of the flu vaccine still require more research. For instance, the labels of many brands of flu vaccine, such as Fluzone and Afluria, directly state that no adequate studies have been done in pregnant women or nursing mothers. They recommend the vaccine should only be administered to pregnant or nursing women if clearly needed.
Another under-studied area is potential side effects of receiving a flu vaccine. In the case of Guillain-Barré syndrome, one study suggested this side effect could be due to bacterial contamination of the eggs used to culture the vaccines. But research remains limited on the definite cause of this and other possible vaccine-induced diseases or how to prevent them.