The National Academy of Sciences issued a press release on its study of studies of vaccines. It is already being used to bash the "anti-vaccine" crowd.  For example, Ron Bailey, the non-libertarian libertarian who also believes in anthropogenic global warming and a global carbon tax, headlined his article on the piece, "For Pete's Sake, Go Get Your Kids Vaccinated Already!"

And from the NAS's own press release:

"With the start of the new school year, it's time to ensure that children are up to date on their immunizations, making this report's findings about the safety of these eight vaccines particularly timely," said committee chair Ellen Wright Clayton, professor of pediatrics and law, and director, Center for Biomedical Ethics and Society, Vanderbilt University, Nashville, Tenn.  "The findings should be reassuring to parents that few health problems are clearly connected to immunizations, and these effects occur relatively rarely.  And repeated study has made clear that some health problems are not caused by vaccines."

But do you know what the study actually concluded? Here is the money shot, from the press release's penultimate paragraph.

"It did not examine information that would have allowed it to draw conclusions about the ratio of benefits to risks."

Here is the list of "vaccine-related adverse effects" culled from the NAS press release.

• Fever-triggered seizures
• Brain inflammation
• Brain swelling
• Pneumonia
• Hepatitis
• Meningitis
• Shingles
• Chickenpox
• Anaphylaxis (an allergic reaction)
• Fainting
• Inflammation of the shoulder
• Joint pain
• Oculo-respiratory syndrome characterized by conjunctivitis
• Facial swelling
• Mild respiratory symptoms

The NAS also concludes, "In many cases of suggested vaccine-related adverse outcomes, there is too little evidence, or the available evidence offers conflicting results or is otherwise inadequate to draw conclusions."

Nowhere in the NAS press release did I find any numbers for the frequency of adverse effects - X effects out of Y vaccinations. But the leading sentence of the press release was this:

"An analysis of more than 1,000 research articles concluded that few health problems are caused by or clearly associated with vaccines." 

There you have it: "few."

As the person, or parent of the person, getting the vaccine, I want to know two numbers for informed consent: (1) chances of dying or adverse effects with the vaccine and (2) chances of dying or adverse effects without the vaccine.

This NAS study quantified neither. For the first, it provided only qualitative values of "few" or "rarely." In fact, it admitted that we cannot "draw conclusions about the ratio of benefits to risks" based on this study. Then why should this be comforting? Are the possibilities of pneumonia, hepatitis and meningitis comforting to you?

By the way, the adverse effect of chickenpox was a potential result of the vaccine against chickenpox.