The evidence does not support the claim that the MMR vaccine causes autism

Pushed by nervous parents and professional agitators, the government keeps commissioning studies of vaccine safety. The latest has just been released for public comment, and you can read the executive summary here. Or you can just go to Orac, doctor and crusader against medical nonsense. This study was produced by the committee charged with figuring out which kinds of possible harm from vaccines will be compensated from the government's fund for vaccine victims, and their charge is essentially to allow payments for any sort of harm for which there is any good evidence. Convincing proof is not required. For most of the posited links between vaccines and disease, the committee found that there was insufficient evidence to say whether there is a link or not. No surprise there, since alarmists keep coming up with reasons to fear vaccines faster than anyone can test the links. But there is enough data to conclude that many of the most famous claims are false:

These include claimed correlations between MMR vaccine and type 1 diabetes, DTaP vaccine and type 1 diabetes, MMR vaccine and autism, inactivated influenza vaccine and asthma exacerbation or reactive airway disease episodes, and inactivated influenza vaccine and Bell's palsy. Let me repeat that again: The evidence does not support the claim that the MMR vaccine causes autism, just as it doesn't support any relationship between vaccines and autism.

The committee did find evidence for the following sorts of harm from vaccines:

• Fever-triggered seizures, which seldom cause long-term consequences, from the measles-mumps-rubella, or MMR, vaccine.
• MMR also can cause a rare form of brain inflammation in some people with immune problems.
• The varicella vaccine against chickenpox sometimes triggers that viral infection, resulting in widespread chickenpox or a painful relative called shingles. It also occasionally can lead to pneumonia, hepatitis or meningitis.
• Six vaccines -- MMR and the chickenpox, hepatitis B, meningococcal and tetanus-containing vaccines -- can cause severe allergic reactions known as anaphylaxis.
• Vaccines in general sometimes trigger fainting or a type of shoulder inflammation.

There *is* something strange and scary about the apparent increases in autism and severe allergies in our time, but there is no evidence at all that those conditions are caused by vaccines. There is very good evidence that vaccines save millions of lives.

On a methodological note, the committee says in their summary that they did not find any one study, no matter how well designed and executed, to be sufficient evidence to make a recommendation. This sort of caution has to be the standard in medical science now, since the field is full of apparently strong research findings that turn out not to be true. Remember that next time you read about a single study that seems to prove something, even if that study comes from top doctors and seems to be really good science.