This language can be found on the CDC and ACOG (American College of OB/GYNs) websites: "There is a flu vaccine made without thimerosal, but experts have not said that the thimerosal-free version is better for any particular group—including children and pregnant women."
"Experts have not said..."
Imagine similar language if I'm trying to sell you an old used car: "Chris has not said that the car has any problems." Does that mean that the car works well and is safe? No. All it means is that I haven't said that the car has any problems. That statement is about me, not the car.
The Comparative Toxicogenomics Database, funded by the US National Institutes of Health, curates high quality research to discover what genes may be impacted by chemical exposure and cause disease. Here's what they've found thus far about thimerosal (mercury) exposure:
See for yourself here.