When we first saw reports that scientists were trying to recreate the 1918 influenza virus that killed 50 million people worldwide, our first thoughts jumped to the potential for a deadly mistake. Maybe we’ve see “Outbreak” reruns on cable TV one too many times, but the idea of engineering one of history’s biggest killers was scary.

The two teams of federal and university researchers, however, have made important discoveries that could help to prevent another pandemic. The scientists found that the 1918 virus, often called the Spanish flu, was a form of bird flu that was transmissible to and between humans. That’s a troubling finding, but one that provides hope.

By unlocking the genetic code of the Spanish flu, scientists have been able to identify some of the changes that make bird flu contagious to people, which makes it particularly dangerous. The Spanish flu was different from other bugs for its ability to attack cells within the lung that are normally immune.

Understanding what made the Spanish flu so deadly is the keystone that future efforts to battle avian flu will be built upon. The knowledge comes with real risk. The Spanish flu has been gone for almost 75 years. Its rebirth, even for the purpose of the destruction of other flu viruses, has potential for great harm. Terrorists salivate over such an efficient killer, and even an accidental release could create chaos around the globe.

Every major scientific advance carries with it elements of misuse. In this case, the risk is worth it if it expands our ability to confront the next pandemic before it gets started. In 1918, the world had not yet discovered viruses; that ignorance offered no protection. Ignorance offers no protection now, either.