Scientists ensure the safety of vaccines by conducting the following types of studies"
- Clinical trials are studies conducted before a vaccine is made available. These studies are carried out by vaccine manufacturers and help the FDA make decisions about if it is safe, effective and ready to be licensed for use.
- Studies, after it is licensed, are conducted after a vaccine is approved by the FDA and made available to the public. These studies continue to monitor vaccine safety and often include groups that are often underrepresented in clinical trials. These studies look for rare adverse reactions.
According to the CDC, on-time vaccination throughout childhood is imperative because it helps provide immunity before children are exposed to potentially life-threatening diseases. Vaccines are tested to ensure that they are safe and effective for children to receive at the recommended ages.
Vaccines and Autism
Some people are concerned about vaccines being linked to the occurrence of autism in people. The studies have shown that there is no link between receiving vaccines and being autistic. In 2011, an Institute of Medicine (IOM) report, on 8 vaccines given to children and adults with rare exceptions, these vaccines are very safe.
A study conducted by the CDC in 2013 added to the research showing that vaccines do not cause autism. They looked at the number of antigens from vaccines during the first two years of life. The results showed that the total number of antigens from vaccines received was the same between autistic children and typical children.
One vaccine ingredient that had been studied specifically was thimerosal. It is a mercury-based preservative. It is used to prevent contamination of multidose vials of vaccines. The research shows that thimerosal does not cause autism. A 2004 scientific review by the IOM concluded that "the evidence favors rejection of a causal relationship between thimerosal-containing
vaccines and autism."They found no link between the MMR vaccine and autism. This substance was removed between 1999 and 2001 to calm the hysteria. There is a trace amount in some flu vaccines. There are thimerosal-free options for people who do not want it in their vaccines.