The Flu Shot

I put together this blog post to educate my readers about the influenza vaccine, specifically the flu shot.   It is essentially a compilation of relevant facts.   I will follow-up with a blog about naturopathic flu prevention and treatment options next week.   The 'flu shot' you're being offered by doctors and pharmacists is the 'inactivated' version (the live version is 'FluMist').

The Evidence:

The Cochrane Library is an extremely highly-regarded database company that regularly reviews the current scientific studies on a particular subject and releases what is referred to as a 'plain language summary' (along with a detailed report) so that anyone can understand the results of their work.   They do this so that we can all benefit from, and practice, evidence-based medicine.  

In 2010 they released a report on 'Vaccines for preventing influenza in healthy adults.'   What follows (in green) is what they refer to as their 'plain language summary'.  Please remember, this pertains to healthy adults aged 16 to 65 years of age:

"Over 200 viruses cause influenza and influenza-like illness which produce the same symptoms (fever, headache, aches and pains, cough and runny noses). Without laboratory tests, doctors cannot tell the two illnesses apart. Both last for days and rarely lead to death or serious illness. At best, vaccines might be effective against only influenza A and B, which represent about 10% of all circulating viruses. Each year, the World Health Organization recommends which viral strains should be included in vaccinations for the forthcoming season.

Authors of this review assessed all trials that compared vaccinated people with unvaccinated people. The combined results of these trials showed that under ideal conditions (vaccine completely matching circulating viral configuration) 33 healthy adults need to be vaccinated to avoid one set of influenza symptoms. In average conditions (partially matching vaccine) 100 people need to be vaccinated to avoid one set of influenza symptoms. Vaccine use did not affect the number of people hospitalised or working days lost but caused one case of Guillian-Barré syndrome (a major neurological condition leading to paralysis) for every one million vaccinations. Fifteen of the 36 trials were funded by vaccine companies and four had no funding declaration. Our results may be an optimistic estimate because company-sponsored influenza vaccines trials tend to produce results favorable to their products and some of the evidence comes from trials carried out in ideal viral circulation and matching conditions and because the harms evidence base is limited."  [http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD001269.pub4/abstract]

I completely understand this review runs counter to what you're being told by the government.  For example, this infographic says that 60 to 80% of healthy adults and children can 'prevent the flu with the flu shot' :

[http://www.health.gov.on.ca/en/pro/programs/publichealth/flu/docs/hcw_11x8.5_infographic.pdf].

One reason for this discrepancy is because the efficacy of the vaccine is extremely dependent on how well-matched the vaccine is to the strain that actually circulates that year.   For example, the CDC released this report in 2008 which stated (in green): 

"... vaccine effectiveness (VE) against culture-confirmed influenza ranged from 71% to 79% when the vaccine and circulating strains were suboptimally matched to 74% to 79% when the matches were well matched... In contrast, a 2-year study of....influenza vaccine among healthy adults aged 18--64 years found no measurable VE during a year when a poorly matched strain circulated"  
[http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5715a1.htm]

The flu shot is less effective in the elderly, and those with compromised immune function.  

How Well Does it Work in Children?

This 2008 study released by a Rochester, New York, hospital was unable to demonstrate vaccine effectiveness (VE) in children in New York state, Ohio, and Tennessee.  They compared kids who had been treated for influenza to kids who were patients of doctors participating in the study.   An excerpt (in green):

"However, significant influenza VE could not be demonstrated for any season, age, or setting after adjusting for county, sex, insurance, chronic conditions recommended for influenza vaccination, and timing of influenza vaccination (VE estimates ranged from 7%-52% across settings and seasons for fully vaccinated 6- to 59-month-olds)"
[http://www.ncbi.nlm.nih.gov/pubmed/18838647]

This is just one study!   However, it did indicate the current state of affairs when I reviewed the research.   The CDC has a fabulous webpage giving details about how effective vaccines are here.   In regards to children, they say:

"Children In a four-year randomized, placebo-controlled study of inactivated and live influenza vaccines among children aged 1–15 years, vaccine efficacy was estimated at 77% against influenza A (H3N2) and 91% against influenza A (H1N1) virus infection (Neuzil et al., 2001). A two-year study of children aged 6–24 months found that the vaccine was 66% effective in preventing laboratory-confirmed influenza in one year of the study (Hoberman et al., 2003)."

Notice, these results pertain only to particular strains of Influenza A.  The first study (Neuzil) talked about kids in 1990, and the second study (Hoberman) actually found that although the vaccines were effective in terms of reducing infection rates, also,:

".... in neither cohort were there any statistically significant differences between the vaccine group and the placebo group during ensuing respiratory seasons regarding utilization of selected health care resources. During the second year of the study the rate of hospitalization was actually higher in the vaccine group than in the placebo group."

[http://jama.jamanetwork.com/article.aspx?articleid=197348]

Last but not least, FluMist is fast becoming the go-to choice for children older than 24 months of age.  

Ingredients:

The flu shot in Canada can contain thimerosal (mercury), formaldehyde, and egg.  
[http://www.gsk.ca/english/docs-pdf/product-monographs/Fluviral.pdf]
[http://www.phac-aspc.gc.ca/publicat/ccdr-rmtc/07vol33/acs-06/index-eng.php]

Side Effects:

This is a tricky subject.  There is a lot of anecdotal evidence out there that vaccines can cause some pretty serious side effects ('anecdotal evidence' means that a lot of people like you and me report it, but it has never been thoroughly scientifically studied or proven).   I would direct my readers to check out The Vaccination Risk Awareness Network for more information at  http://vran.org/about-vaccines/specific-vaccines/influenza-vaccine-flu-shot/

I often hear patients tell me they got sick after they got the flu shot.  You can't get the flu from the flu shot, but it can have an effect on your immune system function. 

When to Seek Help:

The following (in green) is an excerpt from the Ontario Ministry of Health website. 

Call 911 right away or take your child to the nearest hospital emergency department if your child has new onset or worsening of the following symptoms:

• Difficulty breathing / shortness of breath when doing very little or resting
  
• Blue lips, cold feet, hands and/ or toes; sudden paleness
  
• Extreme lack of energy; limp or unconscious
  
• Continuous vomiting or severe diarrhea with signs of dehydration such as dry tongue, dry mouth, decreased peeing (no urine for the past 6-8 hours), or very yellow/ orange urine
  
• Stiff neck, sensitive to light
  
• Seizures or convulsions
  
• Confusion or disorientation
  

[http://health.gov.on.ca/en/public/programs/publichealth/flu/tools/assessment/default.aspx]

If You Get the Flu Shot:

• Don't get it when you're sick.  You're immune system does much better handling one thing at a time.
  
• Avoid taking medication like tylenol, ibuprofen, or aspirin afterwards because they may reduce the efficacy of the vaccine [http://www.sciencedaily.com/releases/2009/12/091201152648.htm]
  

[Image courtesy of 'cooldesign' / freedigitalphotos.net]