Data suggests that 6% of the U.S. population is harboring a retrovirus in their bodies that can develop into an acquired immune deficiency. This is not the well-known AIDS caused by HIV, but Acquired Immune Deficiency Syndrome (AIDS) associated with other retroviruses. These non-HIV retroviruses were unintentionally introduced into humans over the past 75 years.
It began with trials of polio vaccines and yellow fever vaccines given in the early 1930s. This is when the first recorded cases of Chronic Fatigue Syndrome and autism appeared. It involved the use of laboratory mice to prepare vaccines for human use. 
20 Million Americans Likely Infected with Retroviruses
Retrovirus exposure intensified in the 1970s as new vaccines and pharmaceutical products were developed. These retroviruses and related infectious agents are now associated with dozens of modern chronic illnesses – perhaps nearly all of them. In these diseases, infection leads to inflammation — and unresolved inflammation can lead to chronic disease.
The list of diseases stretches from autism to cancer and from Chronic Fatigue Syndrome to Alzheimer’s. The diseases cripple the development of the young, steal the productivity and enjoyment of life for adults, and provide a slow and withering death to the elderly.
via Health Impact News Vaccines and Retroviruses: A Whistleblower Reveals What the Government is Hiding