As the world’s top pharmaceutical companies work to develop a safe and effective coronavirus vaccine, they have been under immense pressure to produce a vaccine that will eliminate the need for the continued shutdowns that have been put in place across the world. This has led to some concerns that when a vaccine is approved, it could be potentially dangerous because the development and approval process, which usually takes years, is being cut short.

To help quell those concerns, the CEOs of nine of the world’s largest drug members issued a rare public letter pledging to “make the safety and well-being of vaccinated individuals our top priority.”

They said they will not submit their vaccine candidates for approval until they have completed a “Phase 3 clinical study that is designed and conducted to meet requirements of expert regulatory authorities such as FDA,” and vowed to “continue to adhere to high scientific and ethical standards.”

The drug companies are hoping to have early results from the tests by the end of the year, as several are currently undergoing the final phase of clinical trials.