This article suggests that observational trials (versus actual clinical trials) have led to public health measures overestimating the effectiveness of flu vaccines in the elderly.

"A growing number of immunologists and epidemiologists say the vaccine probably does not work very well for people over 70, the group that accounts for three-fourths of all flu deaths."

I believe the ethical dilemma is the use of a public health resource (which is limited) on a possibly noneffective or essential treatment.

Here is the article:
http://www.nytimes.com/2008/09/02/health/02flu.html

Comments are welcome

Omai