Most public debate surrounding the hypothetical adverse effects of vaccines is an extension of the polemics, controversies, and discussions that have arisen within the medical field itself. Examples include the adverse effects of the mercury contained in a number of vaccines, such as the one against measles-mumps-rubella (MMR), which can cause inflammatory bowel disease and autism; the link between the hepatitis B vaccine and multiple sclerosis; the polio vaccine, the SV40 virus, and cancer; reverse transcriptase in chicken embryo cells and the risk of infection by retrovirus; and vaccines as a cause of asthma and insulin-dependent diabetes. In some cases, the public health has clearly been harmed-in England, for instance, when alarming reports circulated about the risks of the DTP vaccine in the 1970s or, more recently, involving the MMR vaccine, likewise in England, and the vaccine against hepatitis B, in France. Groups of activists against vaccines have also spread alarming stories through the media, especially the internet. The ones who gain from this situation are the people and lawyers who sue for millions in damages, whether or not their allegations have any scientific basis. This has brought further problems for the public at large, especially in countries like the United States, with the cost of vaccines rising to cover the cost of lawsuits and with a number of companies halting their vaccine production, thus contributing to crises of vaccine availability. Brazil's National Immunization Program has been successful in dealing with the public aspects of adverse events by training the health professionals working in this sector, not just in technical aspects but also in social communication.
vaccines; vaccine adverse events; social reaction