The photo, shared by U.S. Representative Thomas Massie, a Republican from Kentucky, shows three definitions of vaccinations listed by the CDC over the years: one from before 2015, then a change in 2015 and finally an update in 2021. Precaution: A condition in a recipient that could increase the risk of serious side effects, cause diagnostic confusion, or impair the vaccine`s ability to produce immunity. Massie shared an image with three definitions of the word “vaccination” with its 326,000 followers on Sunday. One was described as “before 2015” and described vaccination as: “injection of a killed or weakened infectious organism for the prevention of disease.” Another was dated 2015-2021 and said, “The act of introducing a vaccine into the body to create immunity to a particular disease.” The third was from September 2021 and was called vaccination: “The act of introducing a vaccine into the body to create protection against a particular disease.” Acquired immunodeficiency syndrome (AIDS): A condition in which the immune system cannot function properly and protect the body from disease. As a result, the body cannot defend itself against infections (such as pneumonia). AIDS is caused by the human immunodeficiency virus (HIV). This virus is spread through direct contact with the blood and body fluids of an infected person. High-risk activities include unprotected sex and intravenous drug use (needle sharing). There is no cure for AIDS, but research efforts to develop a vaccine continue.

The CDC previously defined vaccination as: “the act of introducing a vaccine into the body to produce immunity to a particular disease.” Now, according to the September 2021 update, it defines it as: “The act of introducing a vaccine into the body to create protection against a particular disease.” Adjuvant: Listen to the media symbol[MP3] A vaccine component that differs from the antigen and strengthens the immune response to the antigen. For the definition of the vaccine, the CDC has gone from claiming that it is a “product that stimulates a person`s immune system to produce immunity to a particular disease and thereby protect against that disease” to now that it is a “preparation used to stimulate the body`s immune response against a particular disease.” “After Covid-19 vaccines were introduced and found that they did not necessarily prevent disease or `provide immunity,` the CDC again changed the definition of vaccines to say that they `simply create protection.` Booster shots: Additional doses of a vaccine are needed regularly to “boost” the immune system. For example, the tetanus and diphtheria (Td) vaccine, which is recommended for adults every ten years. Epidemic: Listen to the media symbol[MP3] The appearance of diseases in a particular geographic area or population beyond what is normally expected. Therefore, it cannot be confirmed that the CDC took this action due to something they only recently discovered. Verificat tried to contact the CDC to find out the real reason for the definition change, but had not received a response at press time. The McClatchy news agency managed to reach out to a spokesperson for the center, who said the real reason was that previous definitions could be interpreted to mean that vaccines were “100 percent effective, which was not the case with any vaccine,” so the current definition is “more transparent.” Regardless, they add, “it is important to emphasize that the changes to the definition do not change the fact that vaccines and vaccination have prevented millions of infections and saved countless lives.” Conjugate vaccine: listen to the media symbol[MP3] A combination of two compounds (usually a protein and a polysaccharide) to increase the effectiveness of a vaccine. Vaccination: Listen to the multimedia icon [MP3] The physical act of administering a vaccine or toxoid. Langlois stated that the changes also help make the definition more precise. He said the word “immunity” can be misleading with any vaccine because “it`s incredibly rare that this immunity is perfect.” Vaccine: Listen to the media symbol[MP3] A virus related to the cowpox and cowpox viruses used in smallpox vaccine. Vaccine: Listen to the multimedia icon[MP3] Suspension of live (usually attenuated) or inactivated (e.g., bacteria or viruses) microorganisms or fractions thereof, administered to induce immunity and prevent infectious diseases and their consequences.

Some vaccines contain highly defined antigens (for example, Haemophilus influenzae type B polysaccharide or hepatitis B surface antigen); others have complex or incompletely defined antigens (e.g., Bordetella pertussis antigens or live attenuated viruses). Advisory Committee on Immunization Practice (ACIP): A group of medical and public health experts that develops recommendations for the use of vaccines in the U.S. civilian population. The recommendations serve as public health guidelines for the safe use of vaccines and related biologics. This is not the first time the agency has decided to change the definitions of certain terms on its website. Just a few months ago, they rephrased what was meant by “close contact,” and until recently they were also considering changing what`s called “fully vaccinated,” though the CDC has been reluctant to do so until now. Dr. Ryan Langlois, a professor of microbiology and immunology at the University of Minnesota, says the CDC`s changes “make total sense,” adding nuance after emerging developments of vaccines like mRNA technology. The claim has already spread online from other sources, with the false suggestion that the definition changes prove that vaccines don`t work.

“We reused that word, vaccination, from over 200 years ago,” said Langlois, who teaches a course on the history of vaccination. “It`s always hard when a word is so deeply rooted, but technology evolves. I think it`s very, very clear that one of the things the CDC is trying to do is try to update the definition with update technology. Thimerosal: Listen to the media icon[MP3] Thimerosal is a mercury-containing preservative that has been used in some vaccines and other products since the 1930s. There is no convincing evidence of harm caused by low levels of thimerosal in vaccines, except for minor reactions such as redness and swelling at the injection site. However, in July 1999, public health authorities, the American Academy of Pediatrics and vaccine manufacturers agreed to reduce or eliminate thimerosal in vaccines as a precautionary measure. Today, all routinely recommended pediatric vaccines manufactured for the U.S. market contain thimerosal or only trace amounts, with the exception of some flu vaccines. There are flu vaccines without thimerosal. Investigational vaccine: A vaccine approved by the Food and Drug Administration (FDA) for use in human clinical trials. However, experimental vaccines are still in the testing and evaluation stage and are not approved for use by the general public. Attenuated vaccine: listen to the media symbol[MP3] A vaccine in which live microbes are weakened (attenuated) by chemical or physical processes to elicit an immune response without causing the serious effects of disease.

Weakened vaccines currently approved in the United States include measles, mumps, rubella, chickenpox, rotavirus, yellow fever, smallpox, and some formulations of influenza and typhoid vaccines. “While there have been slight changes over time in the wording of the definition of `vaccine` on the CDC website, these have not affected the overall definition,” the statement said, noting that the previous definition “could be interpreted to mean that vaccines are 100 percent effective, which has not been the case with any vaccine.” This change has provoked comments from vaccine skeptics who believe the change is motivated by the increase in infections occurring in the Covid-19 vaccinated population. Yet no vaccine ever approved is 100% effective. The World Health Organization (WHO) and CDC affirm this on their websites, and at Verificat, we point out in this infographic that even the smallpox vaccine, the only disease eradicated in humans in history, is not foolproof. We are a team of young journalists from Barcelona who work independently to combat disinformation in our territory and beyond. We rely on facts and data to verify what politicians are saying and what lies are circulating on social media.