[1][14][15] The group alleges that a large proportion of American children have conditions as diverse as autism, attention deficit hyperactivity disorder, food allergies, cancer, and autoimmune diseases due to exposure to a variety of chemicals and radiation.

[16] The chemicals and radiation that the group has blamed and campaigned against include vaccines, pesticides, fluoridation of drinking water, paracetamol (acetaminophen), aluminum, wireless communications.

[19] Alleging widespread corruption within health care research and collusion by multiple governments, the group endorsed a 2017 edition of the book Judy Mikovits wrote about her discredited theories, with Kennedy writing the foreword.

[6] During the pandemic, the group accused the United States government of supporting research on a vaccine as part of a plan to increase revenues for the pharmaceutical industry.

[9][23] Other misinformation promoted by Children's Health Defense is a conspiracy theory in relation to the Great Reset that claims that elites, including Bill Gates, plan to take over the United States and establish a Marxist high-control regime.

While Kennedy claimed the President agreed to establish a commission to study the risks allegedly associated with vaccines, government officials denied any decision was taken and nothing subsequently came of it.

[25][26] On February 15, 2017, with other anti-vaccination activists and actor Robert De Niro at his side, Kennedy challenged anybody to prove the use of thimerosal is safe "in the amounts contained in vaccines currently being administered to American children and pregnant women", ignoring a 1999 Food and Drug Administration review doing just that.

[35] The organization uses social media and internet advertising to propagate anti-vaccination messages, targeting young parents and minorities in the United States.

[1][2] During the COVID-19 pandemic, those communications attempted to downplay the risk posed by the virus, to argue the new vaccines are dangerous, and to undermine public health authorities.

[47] Echoing other actors in the anti-vaccination movement and Nation of Islam, Children's Health Defense claims that the United States government seeks to harm ethnic minorities by prioritizing them for COVID vaccines.

The conspiracy theory is elaborated upon in an hour-long video production Medical Racism: The New Apartheid released in March 2021 by Children's Health Defense and Kennedy.

[1][48] The organization's social media channels have been shown to amplify conspiracy theories common to other anti-vaccination groups as well as QAnon, such as the "Great Reset" and the "Deep state".

[51] A study found Children's Health Defense was one of major buyers of anti-vaccine Facebook advertising in December 2018 and February 2019, the other being Stop Mandatory Vaccination.

[53][1] Children's Health Defense said that the efficacy of its non-advertising Facebook campaigns has been greatly affected by the platform taking additional measures against misinformation in 2019.

[56][57] In January 2023, CHD filed a complaint alleging the efforts of major news outlets to limit the spread of COVID-19 misinformation amount to a violation to the Sherman Antitrust Act.

[64] Despite its messaging impeding the government's efforts to limit the spread of COVID-19, Children's Health Defense received $145,400 in federally backed small business loans through the Paycheck Protection Program from JPMorgan Chase in 2020.

[58] Given the impact they had during the height of the COVID-19 pandemic, ethicist Arthur Caplan commented that funding Children's Health Defense and similar groups might have grave consequence in future epidemics.

Responding to Children's Health Defense's claims that the city's reaction to a "garden-variety annual measles outbreak" was excessive, the judge pointed out that the documents filed as evidence in fact demonstrated otherwise.

He concluded that "the unvarnished truth is that these diagnoses represent the most significant spike in incidences of measles in the United States in many years and that the Williamsburg section of Brooklyn is at its epicenter.

On January 10, 2023, Children's Health Defense sued Reuters, AP, BBC, and the Washington Post in an antitrust suit, claiming that these groups were working together to keep certain opinions out of the media.

[74] On January 25, 2023,[citation needed] Children's Health Defense sued the FDA under Freedom of Information Act to force release of Vaccine Adverse Event Reporting System data.