This large U.S. study found no association between MMR vaccination before age 2 and childhood autism. Click here to learn more.
Any substance can be
harmful in significantly high doses, even water. Vaccines go through a rigorous approval process with the Food and Drug Administration (FDA) just as over-the-counter and prescription drugs do.
The FDA requires that vaccines undergo an extensive development program in the laboratory, as well as in animal studies and human clinical trials, to determine their safety and effectiveness. Highly trained FDA scientists and clinicians carefully evaluate all of the information and make a determination whether to license (approve) a vaccine before it can be used in the U.S. Prior to licensure, as part of the FDA’s evaluation, it takes all of the ingredients of a vaccine into account, including the active ingredients as well as other substances. After the FDA approves a vaccine, it continuously monitors its safety.
There have been concerns raised about some vaccine ingredients such as aluminum. However, using this as an example, aluminum is also found in drinking water, fruits and vegetables, flour, cereals, nuts, dairy products, honey, antacids, buffered aspirin, antiperspirants, and more.
Sources:
https://www.fda.gov/vaccines-blood-biologics/development-approval-process-cber/vaccine-development-101
https://www.chop.edu/centers-programs/vaccine-education-center/vaccine-ingredients/aluminum
https://www.fda.gov/vaccines-blood-biologics/safety-availability-biologics/common-ingredients-us-licensed-vaccines
The American Academy of Pediatrics currently recommends 15 vaccines for children birth through age 18. Of those, eight were approved between 1987 and 2006. From 1995 to 2010 four new vaccines were added with four updates to previously recommended vaccines. Annual updates to both the childhood and adult immunization schedules offer guidance to health care providers.
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Herd immunity, also known as community immunity, is very real. It protects everyone, but is especially important because some people can’t get vaccinated against certain diseases — such as infants and those with weakened or failing immune systems. If a large portion of the population is immune to those diseases, ideally through vaccination, it is unlikely those diseases can spread.
See how herd immunity works: https://www.historyofvaccines.org/content/herd-immunity-0
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It is extremely unlikely for a vaccine to cause the disease it is designed to prevent. Many vaccines are inactivated, meaning they contain killed viruses that cannot cause illness. New vaccines are often recombinant vaccines. They do not contain the whole virus. They only contain small parts of the virus that elicits an immune response
There are vaccines contain weakened live viruses and these vaccines may cause mild symptoms, such as the minor rash that occasionally occurs after the chickenpox vaccine. These symptoms do not mean the person has developed a full case of the disease.
One historical exception was the oral polio vaccine, which could very rarely cause polio. However, this vaccine is no longer used in the United States. The polio vaccine which is currently used in the United States is a killed vaccine and never causes a polio infection.
https://www.cdc.gov/vaccines/basics/explaining-how-vaccines-work.html
Vaccine preventable diseases have been virtually eliminated. Some vaccine-preventable diseases, like pertussis (whooping cough) and chickenpox, are still present in the US. The main reason that there are so few cases of the other vaccine-preventable diseases in the US is due to vaccines. People becoming vaccinated helped to stop the spread of disease. However, vaccine preventable diseases are still quite prevalent in other countries. Travelers can unknowingly bring these diseases into the US, and if the community is unprotected, the diseases could quickly spread causing outbreaks or epidemics. The relatively few cases that the US may currently have could very quickly become tens or hundreds of thousands of cases without the protection given by vaccines. With adequate vaccination rates, most of these types of outbreaks can be prevented. But if vaccination rates drop, “imported” cases of preventable diseases can begin to spread again.
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