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Clearing the Vaccine Confusion


As a pharmacist, I frequently get questions about medications. But rarely have I received so many questions and overheard so much confusion as I have with the H1N1 vaccine choices. This post will hopefully help you understand the different types of vaccines available.

There are three main types of vaccine that all accomplish the same goal – immunity to H1N1 – but certain types of vaccines are more appropriate for certain populations.

Multi-shot vial

The multi-shot vial vaccine is produced by introducing the killed H1N1 virus into an egg, allowing these dead viral proteins to multiply.  The proteins are then extracted and made into a vaccine.  The vaccine enables your body to build up immunity to the virus without causing the flu.  The multi-shot vial is an injectable vaccine that contains a very small amount of the preservative thimerosal to prevent bacterial contamination of the vial.  Some people are concerned about thimerosal, but according to the FDA and the CDC, there is no conclusive evidence that the amount of thimerosal in vaccines can be linked to autism.  This shot is most appropriate for people over the age of 2 years.

Single Syringe Vaccine

The single syringe vaccine is also an injectable vaccine produced the same way as the multi-shot vial, but it does not contain the preservative thimerosal.  This shot is good for everyone over 6 months of age.  However, children under the age of 2 and pregnant women are being given priority until the vaccine supplies becomes more accessible.

Intranasal Vaccine

The H1N1 nasal vaccine, brand name LAIV, contains a very small amount of live, but weakened, virus that has been harvested after multiplying in eggs.  The live virus in this vaccine has been modified so that it cannot replicate or survive at body temperature.  LAIV is inhaled through the nose and then your body builds natural immunity against the virus while avoiding disease.  The LAIV vaccine should not be given to people who have long-term health problems, a weakened immune system, pregnant women and children taking aspirin long term.  It is recommended for otherwise healthy children and adults ages 2-49 years.  (Children under 2 are not able to get the LAIV vaccine because their immune system is not fully developed.  Adults over the age of 49 are more at risk of having a chronic medical condition that may weaken the immune system.)

FDA-Approved Influenza A

The FDA-approved Influenza A (H1N1) 2009 monovalent vaccines are made in the same licensed facilities and with the same manufacturing processes used to safely produce hundreds of millions of doses of seasonal influenza vaccine every year.  All FDA-approved products have to be tested for safety and efficacy in humans.  Some people are concerned that the vaccines were produced quickly and, therefore, the H1N1 vaccine has not been adequately tested.  In reality, the seasonal flu vaccine is reformulated in the spring every year so that the newest, most prevalent strains are included in the next annual vaccine.  So, the manufacturing process for the H1N1 vaccine has not changed from the way the traditional flu vaccine is produced year to year.

Unless you have an allergy to eggs or other vaccine ingredients or have had a previous life-threatening reaction to influenza vaccination, getting vaccinated is a good idea.  But of course, the best protection against the flu or any virus is prevention, so don’t forget to wash your hands frequently with soap and warm water.

Want to know more about how vaccines are made? Watch this MSNBC slideshow.

About Julie Stauss Geurink, PharmD

Julie is the Emergency Department Pharmacy Clinical Coordinator, WakeMed Raleigh Campus.  She earned a bachelor in LAS concentrated in Chemistry from University of Illinois, Urbana-Champaign and her Doctorate in Pharmacy from the University of Illinois, Chicago. Originally from the suburbs of Chicago, lL., she moved to Raleigh-Durham in October 2009 after working at Mayo Clinic in Rochester for seven years as a Critical Care Pharmacist.