The National Academy of Sciences has just issued yet another report supporting the safety of vaccinations. From the press release

An analysis of more than 1,000 research articles concluded that few health problems are caused by or clearly associated with vaccines.  A committee of experts convened by the Institute of Medicine to review the scientific literature on possible adverse effects of vaccines found convincing evidence of 14 health outcomes -- including seizures, inflammation of the brain, and fainting -- that can be caused by certain vaccines, although these outcomes occur rarely.  It also found indicative though less clear data on associations between specific vaccines and four other effects, such as allergic reactions and temporary joint pain.  In addition, the evidence shows there are no links between immunization and some serious conditions that have raised concerns, including Type 1 diabetes and autism.  The data were inadequate to reach conclusions about other suggested adverse effects. ...

Six vaccines -- MMR, varicella, influenza, hepatitis B, meningococcal, and the tetanus-containing vaccines -- can trigger anaphylaxis, an allergic reaction that appears shortly after injection.  And, in general, the injection of vaccines can trigger fainting and inflammation of the shoulder, the committee noted.  

The evidence suggests that certain vaccines can lead to four other adverse effects, although the data on these links are not as convincing, the report says.  The MMR vaccine appears to trigger short-term joint pain in some women and children. Some people can experience anaphylaxis after receiving the HPV vaccine.  And certain influenza vaccines used abroad have resulted in a mild, temporary oculo-respiratory syndrome characterized by conjunctivitis, facial swelling, and mild respiratory symptoms.

The committee's review also concluded that certain vaccines are not linked to four specific conditions.  The MMR vaccine and diphtheria-tetanus-acellular pertussis (DTaP) do not cause Type 1 diabetes, and the MMR vaccine does not cause autism, according to the results of several studies.  The evidence shows that the flu shot does not cause Bell's palsy or exacerbate asthma.  Suggestions that vaccines can lead to these serious health problems have contributed to parental concerns about immunization for their children. 

Look, vaccines are not perfectly safe. Nothing is. But the scientific evidence clearly shows that the health benefits strongly outweigh the costs. Consider that up to 30 percent of people who get bacterial meningitis die. And especially note that yet another report finds no evidence for a link between vaccination and autism.