Omerta
Medical Control ploys

[And if they think of giving away a colleague then seeing what happens to Whistleblowers should put them off, which is the idea.  Or if someone comes up with information that is not in keeping with the medical propaganda, and sticks to his guns eg Dr. Andy Wakefield.  Most end up leaving the country.]

"Every doctor will allow a colleague to decimate a whole countryside sooner than violate the bond of professional etiquette by giving him away." --George Bernard Shaw

"Every time you hear of the tragic death of an infant, carried off in the first weeks of life by ‘viral meningitis’, you have the right to suspect that BCG is at work, even if the autopsy confirms a viral diagnosis. My wife lived through this tragedy in a major Swiss hospital where she worked. The autopsy of the child revealed the tubercular nature of the ‘viral’ meningitis following a BCG inoculation, but all the assistants and nurses had received very clear instructions to say nothing or risk terrible consequences. As with all secret societies, the law of silence is absolute among doctors!"--Dr Jean Elmiger (Rediscovering Real Medicine ISBN 1862041997)

or intimidate the experts into silence:

Dr. Derek Smith. A neurologist and assistant professor at Harvard Medical School, Smith had been retained to testify for people with transverse myelitis, a potentially paralyzing neurological disorder. Smith said he was "highly confident" that the tetanus vaccine could trigger the ailment in certain vulnerable individuals. Officials with the Vaccine Injury Compensation Program strongly disagreed.  Then Smith quit.  According to court papers and interviews, Smith decided to bail out  after complaints were lodged with his superiors by three other experts with a long history of testifying for the government in vaccine court.....Early in 2002, Smith was informed (that he)  "was ruining his reputation by his testimony  in the vaccine program," ...Wary of antagonizing people who could affect his career, Smith decided to drop out after testifying in one last case, .....Smith was told  in so many words that he was jeopardizing his access to research funding. [Media, 29 Nov 2004] Witnesses for Petitioners Are Often Tough to Find

Another time, Justice Department lawyers persuaded an expert to switch sides, helping them defeat a string of claims. The cases involved children who suffered seizures and brain damage after diphtheria-pertussis-tetanus, or DPT, vaccinations. But the children also had a congenital condition - tuberous sclerosis, or TS - that could trigger seizures by itself. The issue was whether the shot or only TS was to blame. 
    Petitioners won a couple of these cases in the early 1990s, thanks to testimony by Dr. Manuel Gomez of the Mayo Clinic, described in court rulings as "the world's expert in TS."
    Facing at least two dozen similar claims, the government mounted an aggressive counterattack. It retained three experts who then published three medical journal articles that supported the government's stand, according to program records.
    And without the knowledge of petitioners, government attorneys also contacted Gomez, briefed him on the work of their other experts and retained him as a defense expert.
    Gomez was "the guru of tuberous sclerosis," said Robert Moxley, a  Wyoming lawyer for petitioners. His defection "was completely pivotal." Like Chin-Caplan, Moxley described the government's actions as witness tampering.
    In September 1997, Special Master Laura Millman issued a lengthy ruling in the government's favor - basically finding that TS, not the vaccine, is usually responsible when TS infants suffer seizures. Gomez, Millman noted, had believed otherwise, "but in light of his more thorough education in the literature (courtesy of respondent) he has changed his mind."
    Her ruling led to the defeat of most TS claims. [Media, 29 Nov 2004] Witnesses for Petitioners Are Often Tough to Find