I have heard numerous reports in the media where they make mention of the "live flu virus" in the flu vaccine, specifically "flu-mist." This is mentioned in conjunction with a warning to avoid contact with this and that (yadda, yadda) for a certain time period. This confuses me. I was under the impression that the flu vaccines contain dead viruses and that it was not possible to catch the flu from the vaccine. Which is it?
You are right, most vaccines do contain viruses that are dead. FluMist, a nasal spray vaccine, contains live, though severely weakened viruses; weakened enough so that for most people it is pretty darn close to impossible to develop the flu from it. The catch is, in people with compromised immune systems, the vaccine virus can reproduce and create live virus which can cause flu symptoms and even the flu.
Each year influenza affects one in ten Americans, and anyone who's had the flu knows that it is no fun. Common flu symptoms include fever, congestion, fatigue, headache, sore muscles, and a sore throat. Many people, especially those who work in environments that are high-risk for flu like schools and hospitals, choose to be vaccinated to avoid the flu and its complications. While both the live and dead virus forms of vaccination are designed to prevent the strains likely to circulate in a given year, the attenuated (which means weakened) influenza vaccine (LAIV, a nasal spray flu vaccine) is taken through a spray in the nose, while the completely dead vaccine is given as a shot.
FluMist is intended for healthy people between the ages of 2 and 49 who are not pregnant. The flu shot, containing the dead flu vaccine, is intended for children between 6 and 23 months, adults over 50, women in their second or third trimester, or anyone with a compromised immune system or chronic condition. An important additional point is that people with compromised immune systems should avoid close contact with FluMist receivers because they could develop symptoms from exposure to the weakened virus. This precaution could be the instruction to avoid "this and that (yadda, yadda)" that you referred to in your question.
In order for either flu vaccine to be effective, you need to get vaccinated before the flu season peaks, which in the U.S. is usually between December and March.
The FluMist website gives an extensive listing of who should and should not receive this form of vaccination. Some who should not are those who:
- have an allergy or history of allergic reaction to chicken eggs or egg products
- are a child or adolescent who regularly takes aspirin, or products containing aspirin
- have a history of Guillain-Barré syndrome
- have a known or suspected immune deficiency disease
- are pregnant
You can also find more information on flu vaccinations at the Advisory Committee for Immunization Practices (ACIP) website. Finally, if you still have questions about how to best vaccinate yourself for flu this year, or whether you want to go that route at all, you can make an appointment with your health care provider to discuss your particular situation.
Hopefully this cleared up some of the mist enshrouding FluMist. Stay healthy!Alice!