It's called "Believing the first thing you hear or read on the Internet, and automatically rejecting everything you hear or read on the subject after that." It just means that some loony anti-vaxxer got to him/her first.
There ought to be a formal name for the fallacy of assigning greater credibility to earlier information, but I'm not sure what it would be.
No, and I understand why it's necessary to make it difficult to sue vaccine makers. Vaccines are not 100% safe or effective. Nobody ever said they were. The battle against disease cannot be fought with weapons that are 100% safe or effective, because such weapons don't exist. Unfortunately it's true that a very small number of vaccine recipients are going to experience some very severe side effects. Life goes on for the rest of us.
Meanwhile, as long as we rely on private industry to supply the vaccines we need, we have to protect the manufacturers from obviously-frivolous lawsuits that nevertheless require decades of research and millions of dollars in pointless, unproductive studies to prove that they're frivolous. For some reason this field attracts kooks... or haven't you noticed?
There ought to be a formal name for the fallacy of assigning greater credibility to earlier information, but I'm not sure what it would be.