You are exactly right. I know there are always theories about Merck and other Big Pharmas but I don't pay any attention to it. Someone let me know when something is actually proven.
Yeah, not just theories, but actual lawsuits (multiple) brought by scientists that worked for Merck claiming that Merck has been misrepresenting the efficacy rates of the MMR vaccine. What you may not be aware of is that based on its promise that efficacy stay above 95% the US gov't granted Merck the sole manufacturing license of every MMR vaccine made in the US. You may also not be aware that there have been a number of outbreaks in highly vaccinated populations. The scientists claim that, in order to keep the manufacturing license, Merck has been basically lying about the MMR efficacy rate. Based on the outbreaks and the scientists first hand knowledge of the vaccine, that seems like enough initial evidence to keep an eye on the on-going fraud case.
In addition to that fraud case, also ongoing, claiming that Merck has hid data regarding a link between autism and MMR vaccine specifically in young, black boys. I am a little more dubious on this case, but still worth understanding what is going on and what the real story is.
The above linked story appears to be a part of a pattern regarding problems with Merck vaccine manufacturing. It may turn out that the story is inaccurate, but knowing what I already know about Merck I think I will remain a little curious about what might be going on.