Complete and utter nonsense. From the book "Rising from the Dead" (author is a nephrologist who actually dared to report some adverse effects):

I found that there had never been any studies on the effects of seasonal flu vaccines on the kidneys. Few, if any, reactions were reported in the vast body of medical literature. Because the correlation was clear to me, I decided that reactions should be reported to VAERS. Within a few weeks, I had reported four potential adverse events, and that was more than the VAERS system usually hears from one doctor.

They must have thought, ‘There’s either a bad lot of vaccines going around, or there is a crazy doctor.’ They ruled out the bad lot, so they wanted to know why I, compared to all the other nephrologists (who probably like me, didn’t know there was a reporting system!), was officially reporting all these reactions. For the first four reports, I just got the regular phone call to make sure you are who you say you are: you work at the hospital, the patient exists, and you’re not a crank.

Then, one dialysis tech had new onset seizures after his flu vaccine, but didn’t want to report it, because he didn’t think anyone would believe him, and he thought he would be penalized if he did. After I explained the system to him and that he would not be penalized, he filed the report.

In a four-person medical practice, you share a lot of patients and cover for each other. Some of my partners’ patients also had vaccine reactions, which they told me about, knowing I would report to VAERS and spare them the trouble. So I reported for them as well.

At this point, the CDC decided to follow up more intensely. It would usually start with a young woman who would confirm who I was, and then say, “Well, okay, somebody else will be calling you.” Then I would get several calls, and each time I was told, “Someone else will call you,” as if I was being transferred up the CDC hierarchy.

Finally, the CDC director for the state of Maine called me, and kept saying, “What made you change and be different to what you used to be?” Quite apart from the fact that he couldn’t believe my cases were real, he was only really interested in sticking it to me. The conversation really degenerated when I asked him, “What do you think about the fact that we’re vaccinating kids up the nose with a live attenuated flu virus when the package insert says that recipients shouldn’t be around the immunosuppressed or elderly? Does that tell you that vaccinated children might be contagious and spreading the virus?” He said, “I can tell you that this is an area of study for me, and I assure you nasal flu vaccines do not spread the virus and this is absolutely false.” I responded, “Then why does it say that on the package insert? Did you read the symptoms, ‘sore throat, fever, runny nose’ after getting the vaccine and don’t be around immuno-compromised people? To me that says we’re giving these kids the flu and they have capacity to spread it around. I have a problem with that.” Then I said, “And I’ve seen people getting kidney failure after their vaccines, and I’ve reported it. What’s your problem?”

Completely ignoring any science I put to him, he just wanted to compare me to everyone else who never reported reactions. I told him that there may come a time when the same truths that hit me between the eyes will hit other doctors, and he may be getting more reports. After the phone call, which certainly seemed slanted to shut me up, I kept on reporting reactions. But after that, I only got the usual CDC phone calls to verify the case was real.

So, in reality, everything in VAERS is validated. And just ca. 1% of all adverse effects are being reported. And there is a resistance if you report too often.