H1N1 vaccine: the bare facts

 As of November 6th, Illinois  has experienced 1003 confirmed cases of H1N1 hospitilizations and 36 H1N1 related deaths for the year to date.  Of these cases, 272 hospitilizations and 8 deaths occurred during the previous week.  While the vast majority of H1N1 cases will continue to be the few days of achey, feverish, just not feeling at all well type of misery characteristic of the flu, about 1% of those exposed to H1N1 will be at risk of severe complications and possible death.   Fortunately, there is finally a vaccine for H1N1.  Unfortunately, confusion regarding the vaccine's availability and safety abounds, causing panic on the one hand and hesitation on the other.  The importance of knowing the facts is compounded for parents who must decide whether or not to vaccinate their children (the young are among those at highest risk for severe complications if infected).

Following is a break-down of the H1N1 vaccine: how it's made, what's happening with the supply, how it's given (nasal vs. injection), and what we know of its safety. 

Manufacturing the H1N1 vaccine.  Of the 5 companies currently producing the H1N1 vaccine, only one is located in the United States.  Operated by Sanofi Pasteur, the plant utilizes chicken eggs to 'grow' a crop of H1N1 viruses (the eggs are supplied exclusively by a government farm, the location of which is kept secret).  Once grown, the viruses are then killed and incorporated into the vaccine.  This process is identical to that used for decades to produce other vaccines, including yearly influenza shots.  However, the H1N1 virus does not grow well in eggs and so there is a debate regarding adding an adjuvant to help boost the body's immune response.  According to the Centers for Disease Control and Prevention (CDC), the plain vaccine provides a sufficient immune response and so no adjuvants will be added to the U.S.'s H1N1 vaccine supply.    Thimerosal, a mercury-based preservative used to prevent bacterial growth in many intravenous products is only used in multi-dose vials of the vaccine.  It is not present in either the single-use syringes or the nasal mist formulation (which is always a single-dose).

What's the hold-up?  Initial estimates promised a vaccine supply in the range of 120 million doses.  As of last week, just over 24 million doses have been shipped out.  So, what happened?  For starters, it's not inconceivable that companies, vying for government contracts, overestimated their production capabilities.  In addition, the slow growth of the H1N1 virus hampered production.  As the companies continue to learn more about the virus and refine their process accordingly, production will ramp up.  It is important to keep in mind the demand for H1N1 vaccine doses isn't much higher than the current supply.  Those 24 million doses shipped may be far short of the projected estimates, but they're enough to fill 90% of placed orders.  (For a look at the number of doses shipped to various areas, check out this website: www.flu.gov/individualfamily/vaccination/supply.html . )

Injection vs. inhalation.  The H1N1 vaccine is available in two forms: injection and nasal mist.  The difference isn't just superficial (i.e. they don't make the mist for those scared of needles).   H1N1 vaccination administered via injection contains no live virus, relying instead on certain viral markers to provoke an immune response sufficient to launch a defensive attack should the person be exposed to H1N1 in the future.  The nasal spray, however, contains a weakened  (or 'attenuated') form of the virus.  Though the virus cannot survive within the human body, it does trigger an immune response, protecting the individual against future exposure in the same way as the injectable form.  Weakened as it is, the virus is live and there is a risk of infection in those with impaired immune systems.  The nasal mist is only recommended for healthy, non-pregnant individuals aged 2 to 49 years.  Children under 9 years of age should receive 2 doses of the vaccine (regardless of the type used).  The second dose, a 'booster', is given at least 28 days after the first, 'primer' dose.  You can find more information on these vaccines by going to: www.cdc.gov/h1n1flu/vaccination/nasalspray_qa.htm .

How safe is it?  For many people, particularly parents, this is the big question.  A great deal of concern stems from vaccinations given in 1976.  Of 40 million doses given, 400 cases of Guillain-Barre syndrome  (a syndrome involving creeping paralysis, often permanent) were reported.  The cases were never absolutely linked to vaccination and it's never happened again.  Researchers are keeping a close eye on this batch of vaccines.  According to Bruce Gellin, director of the national vaccine program, of the10 million doses administered by late October, not one resulted in side effects more serious than soreness at the injection site or stomach aches.  When weighing the pros and cons of vaccinating yourself or your child, keep in mind the facts.  We know at least 1% of those infected by H1N1 will become seriously ill and may require long-term care.  Meanwhile, if Guillain-Barre is a true risk of innoculation, that risk is 0.001% and, as yet, no side effects have surfaced.  Also, single-dose vaccines do not contain any mercury-based preservatives.   If you're still concerned (and there's absolutely nothing wrong with placing a lot of thought into this decision), talk to a health professional.  You can also check out the national vaccine reporting system, by visiting VAERS' website:vaers.hhs.gov/index  .

Those are the basics.  For more information, stick to reputable sources (the CDC and IDPH websites contain a wealth of information) and utilize your health professionals.  Look for facts. 

If you have questions or comments concerning this topic, please let me know by leaving your thoughts in the 'Comments' section or email me at: christianaki1@hotmail.com.  I'd especially appreciate any first-hand experiences with the vaccine.  Thanks.