Influenza Vaccine and Asthma

This article I found recently in the New York Times struck me as being very similar to the debate at hand in Vaccine Wars. Published in the "Really?" section the article is entitled "The Claim: The Flu Shot Can Worsen Asthma" published on March 25, 2013. It must be noted that the author, Anahad O'Connor, is not in any way a medical doctor and the column is less of an advice piece, and more a dissection of a question in circulation using published medical studies. 

In "The Facts" O'Connor states that "having asthma does not make one more vulnerable to getting the flu. But it does raise the risk of pneumonia and other serious complications. Asthma is the most common medical condition in people hospitalized with the flu." For him, "The Bottom Line" is that "despite concerns that the flu vaccine can provoke asthma, most studies have found that is not the case." 

O'Connor sites two separate medical studies on this issue which I also read on this issue. First is "Does influenza vaccination increase consultations, corticosteroid prescriptions, or exacerbations in subjects with asthma or chronic obstructive pulmonary disease?" published in Thorax, An International Journal of Respiratory Medicine (2003). This article was peer-reviewed. 

• Subject base: 12 000 individuals with asthma or COPD from 432 general practices 
• Methodology: Incidence rate ratios (IRR) calculated for asthma or COPD diagnoses, prescriptions for oral corticosteroids, and acute exacerbations on the day of vaccination and on days 1–2 and 3–14 after vaccination compared with other time periods in the influenza season.
• Results: Older people with asthma or COPD commonly have diagnoses recorded or prescriptions for oral corticosteroids given on the day of influenza vaccination, but there is no increased risk of adverse acute outcomes in the first 2 weeks after vaccination. Our findings strongly suggest that influenza vaccination is safe in this population.

The second study is titled Vaccines for preventing influenza in people with asthma, published February 28, 2013 in the Cochrane Database of Systematic Reviews. 

• Subject Base: We included randomised trials of influenza vaccination in children (over two years of age) and adults with asthma. We excluded studies involving people with chronic obstructive pulmonary disease. First trial: 696 children. Cross-over trials: 1526 adults and 712 children (over three years old)
• Methodology: Nine trials studying lung function following vaccination with both live and inactive vaccines. 
• Results: Uncertainty remains about the degree of protection that vaccination affords against asthma exacerbations that are related to influenza infection. Evidence from more recently published randomised trials of inactivated split-virus influenza vaccination indicates that there is no significant increase in asthma exacerbations immediately after vaccination in adults or children over three years of age. We were unable to address concerns regarding possible increased wheezing and hospital admissions in infants given live intranasal vaccination.

Why I think this particular article is important is that it serves as an example of what could have been done right in the case of the Wakefield Lancet report. Personally I've heard much controversy surrounding flu vaccines, and I can see how this could easily have turned into a similar situation as the MMR vaccination/ Autism issue if someone were to stake the claim that getting a flu vaccine caused their asthma. What these studies do differently is avoid the correlation as causation mistake. Both studies recognize that in some individuals flu vaccinations may exacerbate respiratory problems especially in individuals with asthma or C.O.P.D, but they avoid the assertion that flu vaccinations cause respiratory problems or cause asthma. Overall, I think these is a good example of a question very similar to that of the Lancet report, but one which is properly addressed as to not make the correlation as causation mistake.