(Reuters) -A federal judge has ruled in favor of Merck ( MRK ) in litigation accusing the drugmaker of concealing the risks of Gardasil, a vaccine to prevent cervical and other fatal cancers.

The decision made public on Tuesday by U.S. District Judge Kenneth Bell in Charlotte, North Carolina covers more than 200 cases in the so-called multidistrict litigation.

Plaintiffs argued Merck ( MRK ) should have added warnings to labels for Gardasil about the risk of heart rate increases and ovarian problems allegedly associated with the vaccine.

But the judge said federal law did not give Merck ( MRK ) authority to unilaterally add the requested warnings.

"Federal law requires more than speculative inferences prior to adding dire warnings to lifesaving vaccines that discourage their use," Bell wrote.

Merck ( MRK ) said it was "extremely pleased" with the decision.