I enjoyed Shannon Brownlee and Jeanne Lenzer's boldness in questioning everything we thought we knew about the flu vaccine. I felt that they did not go far enough. The main distraction was the focus on mortality outcomes. This is an example of an irrelevant outcome of a study. Many healthy people get vaccinated not to prevent dying from the flu but to prevent the flu in the first place! I get a flu shot because getting the flu is a pain the ass, not because I'm afraid of dying from it.
Moreover, if vaccination is effective, it also prevents other people from getting sick. It is possible, for instance, to have an whole unit or group out sick just because one person did not get a vaccination. (externalities)
However, they only touch on the general efficacy of the flu vaccine, i.e.:
... vaccine “mismatches” occurred in 1968 and 1997: in both years, the vaccine that had been produced in the summer protected against one set of viruses, but come winter, a different set was circulating. In effect, nobody was vaccinated. Yet death rates from all causes, including flu and the various illnesses it can exacerbate, did not budge.
I would like to be able to replace the phrase "death rates" with "infection rates".
... Studies show that young, healthy people mount a glorious immune response to seasonal flu vaccine, and their response reduces their chances of getting the flu and may lessen the severity of symptoms if they do get it. But they aren’t the people who die from seasonal flu. ... Is vaccine necessary for those in whom it is effective, namely the young and healthy?
Focusing only on the young and healthy, a randomized trial would not have the same ethical problems as a randomized trial of the elderly. They also do not consider the externality effects of vaccination (if vaccination is indeed effective):
From a paper I have yet to read:
Vaccination provides indirect benefits to the unvaccinated. Despite its important policy implications, there is little analytical or empirical work to quantify this externality, nor is it incorporated in a number of cost-benefit studies of vaccine programs. We use a standard epidemiological model to analyze how the magnitude of this externality varies with the number of vaccinations, vaccine efficacy, and disease infectiousness. We also provide empirical estimates using parameters for influenza and mumps epidemics. The pattern of the externality is complex and striking, unlike that suggested in standard treatments. The size of the externality is not necessarily monotonic in the number vaccinated, vaccine efficacy, nor disease infectiousness. Moreover, its magnitude can be remarkably large. In particular, the marginal externality of a vaccination can be greater than one case of illness prevented among the nonvaccinated, so its omission from policy analyses implies serious biases.