Story highlights The government reinstates controversial research to make deadly viruses

If pathogens are mishandled, critics say, millions could be threatened

(CNN) The US government on Tuesday lifted a ban on making lethal viruses, saying the research is necessary to "develop strategies and effective countermeasures against rapidly evolving pathogens that pose a threat to public health."

Dr. Francis Collins, director of the National Institutes of Health, made the announcement, in which he outlined a new framework for the controversial research. The work with three viruses can now go forward, but only if a scientific review panel determines that the benefits outweigh the risks.

"We have a responsibility to ensure that research with infectious agents is conducted responsibly, and that we consider the potential biosafety and biosecurity risks associated with such research," Collins said in a statement

The decision brings an end to a three-year moratorium on research involving the influenza virus, severe acute respiratory syndrome (known as SARS) and Middle East respiratory syndrome (or MERS). Critics say the research could unleash a new germ that threatens millions if it is not properly stored or if it escapes from a lab.

The government paused the research in 2014 to review the practices in handling and storing infectious agents. At the time, Collins said that biosafety and biosecurity risks needed to be "understood better."

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